[OOM-CMPv2] Rename module folder truststoreMerger -> certServicePostProcessor

Issue-ID: DCAEGEN2-2253
Signed-off-by: Jan Malkiewicz <jan.malkiewicz@nokia.com>
Change-Id: I975f37507f7f79c238f1eac15f375fe64761c80c

26 files changed, 1686 insertions, 0 deletions

diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/AppExecutorTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/AppExecutorTest.java
new file mode 100644
index 00000000..19833cb8
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/AppExecutorTest.java
@@ -0,0 +1,76 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+
+package org.onap.oom.certservice.postprocessor;
+
+import static org.mockito.Mockito.doNothing;
+import static org.mockito.Mockito.doThrow;
+import static org.mockito.Mockito.verify;
+import static org.onap.oom.certservice.postprocessor.api.ExitStatus.ALIAS_CONFLICT_EXCEPTION;
+import static org.onap.oom.certservice.postprocessor.api.ExitStatus.SUCCESS;
+import static org.onap.oom.certservice.postprocessor.api.ExitStatus.UNEXPECTED_EXCEPTION;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.onap.oom.certservice.postprocessor.merger.exception.AliasConflictException;
+
+@ExtendWith(MockitoExtension.class)
+class AppExecutorTest {
+
+    @Mock
+    Runnable logic;
+    @Mock
+    AppExitHandler exitHandler;
+    @InjectMocks
+    AppExecutor executor = new AppExecutor();
+
+    @Test
+    void shouldExitWithUnexpectedException() {
+        doThrow(new NullPointerException()).when(logic).run();
+        doNothing().when(exitHandler).exit(UNEXPECTED_EXCEPTION);
+
+        executor.execute(logic);
+
+        verify(exitHandler).exit(UNEXPECTED_EXCEPTION);
+    }
+
+    @Test
+    void shouldExitWithKnownException() {
+        doThrow(new AliasConflictException("")).when(logic).run();
+        doNothing().when(exitHandler).exit(ALIAS_CONFLICT_EXCEPTION);
+
+        executor.execute(logic);
+
+        verify(exitHandler).exit(ALIAS_CONFLICT_EXCEPTION);
+    }
+
+    @Test
+    void shouldExitWithSuccess() {
+        doNothing().when(logic).run();
+        doNothing().when(exitHandler).exit(SUCCESS);
+
+        executor.execute(logic);
+
+        verify(exitHandler).exit(SUCCESS);
+    }
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/common/ExtensionResolverTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/common/ExtensionResolverTest.java
new file mode 100644
index 00000000..8450ab6d
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/common/ExtensionResolverTest.java
@@ -0,0 +1,44 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.common;
+
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.CsvSource;
+
+import java.io.File;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class ExtensionResolverTest {
+
+    @ParameterizedTest
+    @CsvSource(value = {
+        "opt/app/truststore.jks:.jks",
+        "opt/app/truststore.p12:.p12",
+        "opt/app/truststore.pem:.pem",
+        "opt/app/truststore.PEM:.pem",
+        "opt/app/truststore:''",
+    }, delimiter = ':')
+    void shouldReturnCorrectExtension(String filePath, String expectedExtension) {
+        String extension = ExtensionResolver.get(new File(filePath));
+        assertThat(extension).isEqualTo(expectedExtension);
+    }
+
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/common/FileToolsTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/common/FileToolsTest.java
new file mode 100644
index 00000000..7b3b28ae
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/common/FileToolsTest.java
@@ -0,0 +1,71 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.common;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import org.apache.commons.io.FileUtils;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+class FileToolsTest {
+
+    public static final String BAK_EXTENSION = ".bak";
+
+    @TempDir
+    File dir;
+
+    @Test
+    void shouldCreateBackupProvidedFile() throws Exception {
+        //given
+        File fileToBackup = createFile("truststore.pem", "arbitrary content");
+        String backupFilePath = fileToBackup.getPath() + BAK_EXTENSION;
+        //when
+        new FileTools().createBackup(fileToBackup);
+        //then
+        assertThat(fileToBackup).hasSameBinaryContentAs(new File(backupFilePath));
+    }
+
+    @Test
+    void shouldCopyFile() throws IOException {
+        //given
+        File sourceFile = createFile("source.p12", "any content");
+        File destinationFile = new File(dir.getAbsolutePath() + "destination.p12");
+        //when
+        new FileTools().copy(sourceFile, destinationFile);
+        //then
+        assertThat(sourceFile).hasSameBinaryContentAs(destinationFile);
+    }
+
+
+    private File createFile(String name, String content) throws IOException {
+        File file = new File(dir.getAbsolutePath() + File.pathSeparator + name);
+        if (file.createNewFile()) {
+            FileUtils.write(file, content, Charset.defaultCharset());
+        } else {
+            throw new IllegalStateException("File could not be created: " + file.getAbsolutePath());
+        }
+        return file;
+    }
+
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/common/PasswordReaderTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/common/PasswordReaderTest.java
new file mode 100644
index 00000000..697eaa83
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/common/PasswordReaderTest.java
@@ -0,0 +1,43 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.common;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.File;
+import org.onap.oom.certservice.postprocessor.merger.exception.PasswordReaderException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+class PasswordReaderTest {
+
+    @Test
+    void shouldReturnCorrectPasswordFromFile() throws PasswordReaderException {
+        String fileData = PasswordReader.readPassword(new File("src/test/resources/truststore-jks.pass"));
+        assertThat(fileData).isEqualTo("EOyuFbuYDyq_EhpboM72RHua");
+    }
+
+    @Test
+    void shouldThrowExceptionForNonExistingFile() {
+        assertThatExceptionOfType(PasswordReaderException.class)
+                .isThrownBy(() -> PasswordReader.readPassword(new File("src/test/resources/non-esisting-file.pass")));
+    }
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/AppConfigurationProviderTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/AppConfigurationProviderTest.java
new file mode 100644
index 00000000..24e2dab8
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/AppConfigurationProviderTest.java
@@ -0,0 +1,141 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.configuration;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.mockito.Mockito.when;
+import static org.onap.oom.certservice.postprocessor.configuration.model.EnvVariable.KEYSTORE_DESTINATION_PATHS;
+import static org.onap.oom.certservice.postprocessor.configuration.model.EnvVariable.KEYSTORE_SOURCE_PATHS;
+import static org.onap.oom.certservice.postprocessor.configuration.model.EnvVariable.TRUSTSTORES_PASSWORDS_PATHS;
+import static org.onap.oom.certservice.postprocessor.configuration.model.EnvVariable.TRUSTSTORES_PATHS;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.onap.oom.certservice.postprocessor.configuration.exception.CertificatesPathsValidationException;
+import org.onap.oom.certservice.postprocessor.configuration.exception.ConfigurationException;
+import org.onap.oom.certservice.postprocessor.configuration.model.AppConfiguration;
+import org.onap.oom.certservice.postprocessor.configuration.path.DelimitedPathsSplitter;
+import org.onap.oom.certservice.postprocessor.configuration.path.env.EnvReader;
+
+@ExtendWith(MockitoExtension.class)
+class AppConfigurationProviderTest {
+
+    private static final String BASE_TRUSTSTORE_PATH = "/opt/app/truststore_";
+    private static final String JKS_EXTENSION = ".jks";
+    private static final String PASS_EXTENSION = ".pass";
+    private static final String SAMPLE_TRUSTSTORES_PATHS = "/opt/app/certificates/truststore.jks:/opt/app/certificates/truststore.pem";
+    private static final String SAMPLE_TRUSTSTORES_PASSWORDS_PATHS = "/opt/app/certificates/truststore.pass:/trust.pass";
+
+    @Mock
+    private DelimitedPathsSplitter pathsSplitter;
+    @Mock
+    private EnvReader envReader;
+    private AppConfigurationProvider provider;
+
+    @BeforeEach
+    void setUp() {
+        provider = new AppConfigurationProvider(pathsSplitter, envReader);
+    }
+
+    @Test
+    void shouldThrowExceptionWhenMandatoryEnvNotPresent() {
+        // given
+        when(envReader.getEnv(TRUSTSTORES_PATHS.name())).thenReturn(Optional.empty());
+        // when, then
+        assertThatExceptionOfType(ConfigurationException.class).isThrownBy(() -> provider.createConfiguration())
+            .withMessageContaining(TRUSTSTORES_PATHS + " mandatory environment variable is not defined");
+    }
+
+    @Test
+    void shouldThrowExceptionWhenTrustorePathsSizesDoNotMatch() {
+        // given
+        List<String> truststores = createListOfPathsWithExtension(2, JKS_EXTENSION);
+        List<String> truststoresPasswords = createListOfPathsWithExtension(1, PASS_EXTENSION);
+
+        mockTruststorePaths(truststores, truststoresPasswords);
+        // when, then
+        assertThatExceptionOfType(ConfigurationException.class)
+            .isThrownBy(() -> provider.createConfiguration())
+            .withMessageContaining("Size of " + TRUSTSTORES_PATHS
+                + " does not match size of " + TRUSTSTORES_PASSWORDS_PATHS + " environment variables");
+    }
+
+    @Test
+    void shouldReturnEmptyListWhenOptionalEnvNotPresent() {
+        // given
+        List<String> truststores = createListOfPathsWithExtension(2, JKS_EXTENSION);
+        List<String> truststoresPasswords = createListOfPathsWithExtension(2, PASS_EXTENSION);
+        mockTruststorePaths(truststores, truststoresPasswords);
+        mockKeystorePaths(Optional.empty(), Optional.empty());
+        // when
+        AppConfiguration paths = provider.createConfiguration();
+        // then
+        assertThat(paths.getDestinationKeystorePaths()).isEmpty();
+        assertThat(paths.getSourceKeystorePaths()).isEmpty();
+    }
+
+    private void mockTruststorePaths(List<String> truststores, List<String> truststoresPasswords) {
+        mockTruststores(truststores);
+        mockTruststoresPasswords(truststoresPasswords);
+    }
+
+    private void mockKeystorePaths(Optional<String> sourceKeystoresPairPaths, Optional<String> destKeystoresPairPaths) {
+        mockKeystoreCopierSourcePaths(sourceKeystoresPairPaths);
+        mockKeystoreCopierDestinationPaths(destKeystoresPairPaths);
+    }
+
+    private void mockTruststores(List<String> truststores) throws CertificatesPathsValidationException {
+        when(envReader.getEnv(TRUSTSTORES_PATHS.name())).thenReturn(Optional.of(SAMPLE_TRUSTSTORES_PATHS));
+        when(pathsSplitter.getValidatedPaths(TRUSTSTORES_PATHS, Optional.of(SAMPLE_TRUSTSTORES_PATHS)))
+            .thenReturn(truststores);
+    }
+
+    private void mockTruststoresPasswords(List<String> truststoresPasswords)
+        throws CertificatesPathsValidationException {
+        Optional<String> passwordsPaths = Optional.of(SAMPLE_TRUSTSTORES_PASSWORDS_PATHS);
+        when(envReader.getEnv(TRUSTSTORES_PASSWORDS_PATHS.name())).thenReturn(passwordsPaths);
+        when(pathsSplitter.getValidatedPaths(TRUSTSTORES_PASSWORDS_PATHS, passwordsPaths))
+            .thenReturn(truststoresPasswords);
+    }
+
+    private void mockKeystoreCopierSourcePaths(Optional<String> paths) {
+        when(envReader.getEnv(KEYSTORE_SOURCE_PATHS.name())).thenReturn(paths);
+    }
+
+    private void mockKeystoreCopierDestinationPaths(Optional<String> paths) {
+        when(envReader.getEnv(KEYSTORE_DESTINATION_PATHS.name())).thenReturn(paths);
+    }
+
+    private List<String> createListOfPathsWithExtension(int numberOfPaths, String passwordExtension) {
+        List<String> paths = new ArrayList<>();
+        while (numberOfPaths-- > 0) {
+            paths.add(BASE_TRUSTSTORE_PATH + numberOfPaths + passwordExtension);
+        }
+        return paths;
+    }
+
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/path/DelimitedPathsSplitterTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/path/DelimitedPathsSplitterTest.java
new file mode 100644
index 00000000..be1bc394
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/path/DelimitedPathsSplitterTest.java
@@ -0,0 +1,107 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.configuration.path;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.onap.oom.certservice.postprocessor.configuration.model.EnvVariable.TRUSTSTORES_PASSWORDS_PATHS;
+import static org.onap.oom.certservice.postprocessor.configuration.model.EnvVariable.TRUSTSTORES_PATHS;
+
+import java.util.Optional;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.onap.oom.certservice.postprocessor.configuration.exception.CertificatesPathsValidationException;
+
+@ExtendWith(MockitoExtension.class)
+class DelimitedPathsSplitterTest {
+
+    private static final String VALID_TRUSTSTORES = "/opt/app/certificates/truststore.jks:/opt/app/certificates/truststore.pem";
+    private static final String VALID_TRUSTSTORES_PASSWORDS = "/opt/app/certificates/truststore.pass:";
+    private static final String VALID_TRUSTSTORES_PASSWORDS_WITH_EMPTY_IN_THE_MIDDLE = "/opt/app/certificates/truststore.pass::/etc/truststore.pass";
+    private static final String INVALID_TRUSTSTORES = "/opt/app/certificates/truststore.jks:/opt/app/certificates/truststore.invalid";
+    private static final String INVALID_TRUSTSTORES_PASSWORDS = "/opt/app/certificates/truststore.pass:/.pass";
+
+    private DelimitedPathsSplitter delimitedPathsSplitter;
+
+    @BeforeEach
+    void setUp() {
+        delimitedPathsSplitter = new DelimitedPathsSplitter();
+    }
+
+    @Test
+    void shouldReturnCorrectListWhenTruststoresValid() {
+        // when, then
+        assertThat(delimitedPathsSplitter.getValidatedPaths(TRUSTSTORES_PATHS, Optional.of(VALID_TRUSTSTORES)))
+            .containsSequence("/opt/app/certificates/truststore.jks",
+                "/opt/app/certificates/truststore.pem");
+    }
+
+    @Test
+    void shouldThrowExceptionWhenTruststoresPathsEnvIsEmpty() {
+        // when, then
+        assertThatExceptionOfType(CertificatesPathsValidationException.class)
+            .isThrownBy(() -> delimitedPathsSplitter.getValidatedPaths(TRUSTSTORES_PATHS, Optional.of("")));
+    }
+
+    @Test
+    void shouldThrowExceptionWhenOneOfTruststoresPathsInvalid() {
+        // when, then
+        assertThatExceptionOfType(CertificatesPathsValidationException.class)
+            .isThrownBy(() -> delimitedPathsSplitter
+                .getValidatedPaths(TRUSTSTORES_PATHS, Optional.of(INVALID_TRUSTSTORES)));
+    }
+
+    @Test
+    void shouldReturnCorrectListWhenTruststoresPasswordsValid() {
+        // when, then
+        assertThat(delimitedPathsSplitter
+            .getValidatedPaths(TRUSTSTORES_PASSWORDS_PATHS, Optional.of(VALID_TRUSTSTORES_PASSWORDS)))
+            .containsSequence("/opt/app/certificates/truststore.pass", "");
+    }
+
+    @Test
+    void shouldReturnCorrectListWhenTruststoresPasswordsContainsEmptyPathsInTheMiddle() {
+        // when, then
+        assertThat(delimitedPathsSplitter.getValidatedPaths(TRUSTSTORES_PASSWORDS_PATHS,
+            Optional.of(VALID_TRUSTSTORES_PASSWORDS_WITH_EMPTY_IN_THE_MIDDLE))).containsSequence(
+            "/opt/app/certificates/truststore.pass",
+            "",
+            "/etc/truststore.pass"
+        );
+    }
+
+    @Test
+    void shouldThrowExceptionWhenTruststoresPasswordsPathEnvIsEmpty() {
+        // when, then
+        assertThatExceptionOfType(CertificatesPathsValidationException.class)
+            .isThrownBy(
+                () -> delimitedPathsSplitter.getValidatedPaths(TRUSTSTORES_PASSWORDS_PATHS, Optional.of("")));
+    }
+
+    @Test
+    void shouldThrowExceptionWhenOneOfTruststorePasswordPathsInvalid() {
+        // when, then
+        assertThatExceptionOfType(CertificatesPathsValidationException.class)
+            .isThrownBy(() -> delimitedPathsSplitter
+                .getValidatedPaths(TRUSTSTORES_PASSWORDS_PATHS, Optional.of(INVALID_TRUSTSTORES_PASSWORDS)));
+    }
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/path/env/EnvReaderTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/path/env/EnvReaderTest.java
new file mode 100644
index 00000000..343e5655
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/path/env/EnvReaderTest.java
@@ -0,0 +1,62 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.configuration.path.env;
+
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.when;
+import static org.onap.oom.certservice.postprocessor.configuration.model.EnvVariable.TRUSTSTORES_PASSWORDS_PATHS;
+
+import java.util.Optional;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+
+class EnvReaderTest {
+
+    private static final String SAMPLE_PASS_PATH = "/sample/path/trust.pass";
+    EnvReader provider;
+
+    @BeforeEach
+    void setUp() {
+        provider = Mockito.spy(EnvReader.class);
+    }
+
+    @Test
+    void shouldReturnOptionalWithEnv() {
+        // given
+        String envName = TRUSTSTORES_PASSWORDS_PATHS.name();
+        when(provider.getSystemEnv(envName)).thenReturn(Optional.of(SAMPLE_PASS_PATH));
+        // when
+        Optional<String> result = provider.getEnv(envName);
+        // then
+        assertThat(result).isEqualTo(Optional.of(SAMPLE_PASS_PATH));
+    }
+
+    @Test
+    void shouldReturnEmptyOptional() {
+        // given
+        String envName = TRUSTSTORES_PASSWORDS_PATHS.name();
+        // when
+        Optional<String> result = provider.getEnv(envName);
+        // then
+        assertThat(result).isEmpty();
+    }
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/path/validation/ValidationFunctionsTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/path/validation/ValidationFunctionsTest.java
new file mode 100644
index 00000000..f65147a9
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/configuration/path/validation/ValidationFunctionsTest.java
@@ -0,0 +1,135 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.configuration.path.validation;
+
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.onap.oom.certservice.postprocessor.configuration.path.validation.ValidationFunctions.doesItContainValidCertificatesPaths;
+import static org.onap.oom.certservice.postprocessor.configuration.path.validation.ValidationFunctions.doesItContainValidPasswordPaths;
+import static org.onap.oom.certservice.postprocessor.configuration.path.validation.ValidationFunctions.doesItContainValidPathsToCopy;
+
+import java.util.Arrays;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+class ValidationFunctionsTest {
+
+    @Test
+    void shouldValidateWithSuccessCorrectCertificatesPaths() {
+        // given
+        List<String> certPaths = Arrays.asList("/opt/app/certificates/truststore.p12");
+        // when
+        boolean result = doesItContainValidCertificatesPaths().test(certPaths);
+        // then
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    void shouldValidateWithFailureCertificatesPathsWithOneEmptyPath() {
+        // given
+        List<String> certPaths = Arrays.asList("/opt/app/certificates/truststore.p12", "");
+        // when
+        boolean result = doesItContainValidCertificatesPaths().test(certPaths);
+        // then
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void shouldValidateWithFailureCertificatesPathsWithOnePathWhichHasIncorrectExtension() {
+        // given
+        List<String> certPaths = Arrays.asList("/opt/app/certificates/truststore.txt", "/opt/cert.p12");
+        // when
+        boolean result = doesItContainValidCertificatesPaths().test(certPaths);
+        // then
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void shouldValidateWithSuccessCertificatesPasswordPaths() {
+        // given
+        List<String> passwordPaths = Arrays.asList("/opt/app/certificates/truststore.pass", "");
+        // when
+        boolean result = doesItContainValidPasswordPaths().test(passwordPaths);
+        // then
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    void shouldValidateWithSuccessCertificatePasswordsPathsWhichContainsEmptyPathsInTheMiddle() {
+        // given
+        List<String> passwordPaths = Arrays.asList("/opt/app/certificates/truststore.pass", "", "/etc/truststore.pass");
+        // when
+        boolean result = doesItContainValidPasswordPaths().test(passwordPaths);
+        // then
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    void shouldValidateWithFailureCertificatesPasswordsPathsWithIncorrectExtension() {
+        // given
+        List<String> passwordPaths = Arrays.asList("/pass.txt");
+        // when
+        boolean result = doesItContainValidPasswordPaths().test(passwordPaths);
+        // then
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void shouldValidateWithFailureCertificatesPasswordPathsWithMissingPrecedingSlash() {
+        // given
+        List<String> passwordPaths = Arrays.asList("jks.pass");
+        // when
+        boolean result = doesItContainValidPasswordPaths().test(passwordPaths);
+        // then
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void shouldValidateWithSuccessSourcePathsToCopyFiles() {
+        // given
+        List<String> sourcePaths = Arrays.asList("/opt/dcae/cacert/external/keystore.p12",
+            "/opt/dcae/cacert/external/keystore.pass");
+        // when
+        boolean result = doesItContainValidPathsToCopy().test(sourcePaths);
+        // then
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    void shouldValidateWithSuccessDestinationPathsToCopyFiles() {
+        // given
+        List<String> sourcePaths = Arrays.asList("/opt/dcae/cacert/cert.p12","/opt/dcae/cacert/p12.pass");
+        // when
+        boolean result = doesItContainValidPathsToCopy().test(sourcePaths);
+        // then
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    void shouldValidateWithFailureDestinationPathsWithIncorrectExtension() {
+        // given
+        List<String> sourcePaths = Arrays.asList("/opt/dcae/cacert/cert.txt","/opt/dcae/cacert/p12.other");
+        // when
+        boolean result = doesItContainValidPathsToCopy().test(sourcePaths);
+        // then
+        assertThat(result).isFalse();
+    }
+
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/copier/KeystoreCopierTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/copier/KeystoreCopierTest.java
new file mode 100644
index 00000000..99193a8d
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/copier/KeystoreCopierTest.java
@@ -0,0 +1,147 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.copier;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.util.Collections;
+import org.apache.commons.io.FileUtils;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+import org.onap.oom.certservice.postprocessor.common.FileTools;
+import org.onap.oom.certservice.postprocessor.configuration.model.AppConfiguration;
+import org.onap.oom.certservice.postprocessor.copier.exception.KeystoreFileCopyException;
+import org.onap.oom.certservice.postprocessor.copier.exception.KeystoreNotExistException;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+public class KeystoreCopierTest {
+
+    private static final String SOURCE_CONTENT = "source content";
+    private static final String DESTINATION_CONTENT = "destination content";
+
+    @TempDir
+    File dir;
+
+    private KeystoreCopier copier = new KeystoreCopier(new FileTools());
+
+    @Test
+    void shouldDoNothingForEmptySourceFileList() {
+        AppConfiguration configuration = createEmptyConfiguration();
+
+        copier.copyKeystores(configuration);
+
+        assertThat(dir.listFiles()).isEmpty();
+    }
+
+
+    @Test
+    void shouldCopyFileAndCreateBackup() throws IOException {
+        File source = createFile("source.p12", SOURCE_CONTENT);
+        File destination = createFile("destination.p12", DESTINATION_CONTENT);
+        File backup = declareFile("destination.p12.bak");
+        AppConfiguration configuration = createConfiguration(source, destination);
+
+        copier.copyKeystores(configuration);
+
+        assertThat(readFile(destination)).isEqualTo(readFile(source));
+        assertThat(backup.exists()).isTrue();
+        assertThat(readFile(backup)).isEqualTo(DESTINATION_CONTENT);
+    }
+
+    @Test
+    void shouldCopyFileWithoutCreatingBackup() throws IOException {
+        File source = createFile("source.p12", SOURCE_CONTENT);
+        File destination = declareFile("destination.p12");
+        File backup = declareFile("destination.p12.bak");
+        AppConfiguration configuration = createConfiguration(source, destination);
+
+        copier.copyKeystores(configuration);
+
+        assertThat(destination.exists()).isTrue();
+        assertThat(readFile(destination)).isEqualTo(readFile(source));
+        assertThat(backup.exists()).isFalse();
+    }
+
+    @Test
+    void shouldThrowKeystoreNotExistException() throws IOException {
+        File source = declareFile("source.p12");
+        File destination = declareFile("destination.p12");
+        File backup = declareFile("destination.p12.bak");
+        AppConfiguration configuration = createConfiguration(source, destination);
+
+        assertThatExceptionOfType(KeystoreNotExistException.class).isThrownBy( () ->
+            copier.copyKeystores(configuration)
+        );
+
+        assertThat(source.exists()).isFalse();
+        assertThat(destination.exists()).isFalse();
+        assertThat(backup.exists()).isFalse();
+    }
+
+    @Test
+    void shouldThrowKeystoreFileCopyException() throws IOException {
+        File source = createFile("source.p12", SOURCE_CONTENT);
+        source.setReadable(false);
+        File destination = declareFile("destination.p12");
+        File backup = declareFile("destination.p12.bak");
+        AppConfiguration configuration = createConfiguration(source, destination);
+
+        assertThatExceptionOfType(KeystoreFileCopyException.class).isThrownBy( () ->
+            copier.copyKeystores(configuration)
+        );
+
+        assertThat(source.exists()).isTrue();
+        assertThat(destination.exists()).isFalse();
+        assertThat(backup.exists()).isFalse();
+    }
+
+    private AppConfiguration createConfiguration(File source, File destination) {
+        return new AppConfiguration(Collections.emptyList(), Collections.emptyList(),
+            Collections.singletonList(source.getAbsolutePath()),
+            Collections.singletonList(destination.getAbsolutePath()));
+    }
+
+    private AppConfiguration createEmptyConfiguration() {
+        return new AppConfiguration(Collections.emptyList(), Collections.emptyList(),
+            Collections.emptyList(),
+            Collections.emptyList());
+    }
+
+    private String readFile(File file) throws IOException {
+        return FileUtils.readFileToString(file, Charset.defaultCharset());
+    }
+
+    private File declareFile(String name) {
+        return new File(dir.getAbsolutePath() + File.pathSeparator + name);
+    }
+
+    private File createFile(String name, String content) throws IOException {
+        File file = new File(dir.getAbsolutePath() + File.pathSeparator + name);
+        if (file.createNewFile()) {
+            FileUtils.write(file, content, Charset.defaultCharset());
+        } else {
+            throw new IllegalStateException("File could not be created: " + file.getAbsolutePath());
+        }
+        return file;
+    }
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/TruststoreFilesProviderTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/TruststoreFilesProviderTest.java
new file mode 100644
index 00000000..9040b53d
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/TruststoreFilesProviderTest.java
@@ -0,0 +1,63 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+
+package org.onap.oom.certservice.postprocessor.merger;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Arrays;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+import org.onap.oom.certservice.postprocessor.merger.exception.KeystoreInstanceException;
+import org.onap.oom.certservice.postprocessor.merger.exception.LoadTruststoreException;
+import org.onap.oom.certservice.postprocessor.merger.exception.PasswordReaderException;
+import org.onap.oom.certservice.postprocessor.merger.exception.TruststoreFileFactoryException;
+import org.onap.oom.certservice.postprocessor.merger.model.Truststore;
+import org.onap.oom.certservice.postprocessor.merger.model.TruststoreFactory;
+
+class TruststoreFilesProviderTest {
+
+    private static final String TRUSTSTORE_JKS_PATH = "src/test/resources/truststore-jks.jks";
+    private static final String TRUSTSTORE_JKS_PASS_PATH = "src/test/resources/truststore-jks.pass";
+    private static final String TRUSTSTORE_P12_PATH = "src/test/resources/truststore-p12.p12";
+    private static final String TRUSTSTORE_P12_PASS_PATH = "src/test/resources/truststore-p12.pass";
+    private static final String TRUSTSTORE_PEM_PATH = "src/test/resources/truststore.pem";
+    private static final String EMPTY_PASS_PATH = "";
+
+    @Test
+    void shouldReturnTruststoreFilesList()
+        throws TruststoreFileFactoryException, PasswordReaderException, LoadTruststoreException, KeystoreInstanceException {
+        //given
+        List<String> truststorePaths = Arrays.asList(TRUSTSTORE_JKS_PATH, TRUSTSTORE_P12_PATH, TRUSTSTORE_PEM_PATH);
+        List<String> truststorePasswordPaths = Arrays
+            .asList(TRUSTSTORE_JKS_PASS_PATH, TRUSTSTORE_P12_PASS_PATH, EMPTY_PASS_PATH);
+
+        //when
+        List<Truststore> truststoreFilesList = TruststoreFilesProvider
+            .getTruststoreFiles(truststorePaths, truststorePasswordPaths);
+
+        //then
+        assertThat(truststoreFilesList.size()).isEqualTo(3);
+        TruststoreFactory.create(TRUSTSTORE_JKS_PATH, TRUSTSTORE_JKS_PASS_PATH);
+        TruststoreFactory.create(TRUSTSTORE_P12_PATH, TRUSTSTORE_P12_PASS_PATH);
+        TruststoreFactory.create(TRUSTSTORE_PEM_PATH, EMPTY_PASS_PATH);
+    }
+
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/JavaTruststoreTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/JavaTruststoreTest.java
new file mode 100644
index 00000000..93a5359b
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/JavaTruststoreTest.java
@@ -0,0 +1,56 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.merger.model;
+
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+import java.util.List;
+import org.junit.jupiter.api.Test;
+import org.onap.oom.certservice.postprocessor.api.ExitableException;
+import org.onap.oom.certservice.postprocessor.merger.exception.AliasConflictException;
+import org.onap.oom.certservice.postprocessor.merger.exception.MissingTruststoreException;
+import org.onap.oom.certservice.postprocessor.merger.model.certificate.CertificateWithAlias;
+
+class JavaTruststoreTest {
+
+    @Test
+    void throwExceptionWhenAliasConflictDetected() throws Exception {
+        //given
+        Truststore p12Truststore = TestCertificateProvider.getSampleP12Truststore();
+
+        List<CertificateWithAlias> certificateFromJks = TestCertificateProvider
+            .getSampleJksTruststoreFile().getCertificates();
+
+        //when //then
+        assertThatExceptionOfType(AliasConflictException.class)
+            .isThrownBy(() -> p12Truststore.addCertificates(certificateFromJks));
+    }
+
+    @Test
+    void throwExceptionWhenFileNotContainsTruststoreEntry() throws ExitableException {
+        //given
+        Truststore p12Truststore = TestCertificateProvider.getSampleP12Keystore();
+
+        //when//then
+        assertThatExceptionOfType(MissingTruststoreException.class)
+            .isThrownBy(() -> p12Truststore.getCertificates());
+    }
+
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/PemTruststoreTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/PemTruststoreTest.java
new file mode 100644
index 00000000..af254896
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/PemTruststoreTest.java
@@ -0,0 +1,128 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.merger.model;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.mockito.Mockito.mock;
+
+import java.io.File;
+import java.io.IOException;
+import java.security.KeyStore;
+import java.security.KeyStoreSpi;
+import java.security.cert.Certificate;
+import java.util.List;
+import java.util.stream.Collectors;
+import org.junit.jupiter.api.Test;
+import org.onap.oom.certservice.postprocessor.api.ExitableException;
+import org.onap.oom.certservice.postprocessor.merger.exception.MissingTruststoreException;
+import org.onap.oom.certservice.postprocessor.merger.exception.TruststoreDataOperationException;
+import org.onap.oom.certservice.postprocessor.merger.exception.WriteTruststoreFileException;
+import org.onap.oom.certservice.postprocessor.merger.model.certificate.CertificateWithAlias;
+
+class PemTruststoreTest {
+
+    private static final int EXPECTED_ONE = 1;
+
+    @Test
+    void getCertificatesShouldThrowExceptionWhenFileNotContainsCertificate() {
+        //given
+        File emptyPemFile = TestCertificateProvider.getEmptyPemFile();
+        PemTruststore pemCertificate = new PemTruststore(emptyPemFile);
+        //when//then
+        assertThatExceptionOfType(MissingTruststoreException.class)
+            .isThrownBy(pemCertificate::getCertificates);
+    }
+
+    @Test
+    void shouldThrowExceptionWhenCannotSaveFile() {
+        //given
+        KeyStoreSpi keyStoreSpi = mock(KeyStoreSpi.class);
+        KeyStore keyStore = new KeyStore(keyStoreSpi, null, "") {
+        };
+        File pemFile = TestCertificateProvider.getEmptyPemFile();
+        pemFile.setWritable(false);
+        PemTruststore pem = new PemTruststore(pemFile);
+
+        //when. then
+        assertThatExceptionOfType(WriteTruststoreFileException.class)
+            .isThrownBy(pem::saveFile);
+    }
+
+    @Test
+    void transformToStringInPemFormatShouldCorrectlyTransform() throws ExitableException, IOException {
+        //given
+        Truststore pemTruststore = TestCertificateProvider.getSamplePemTruststoreFile();
+
+        List<CertificateWithAlias> wrappedCertificates = pemTruststore.getCertificates();
+        List<Certificate> certificateList = unWrapCertificate(wrappedCertificates);
+        File notEmptyPemFile = TestCertificateProvider.getNotEmptyPemFile();
+        PemTruststore pemCertificate = new PemTruststore(notEmptyPemFile);
+
+        //when
+        String certificateTransformed = pemCertificate.transformToStringInPemFormat(certificateList);
+
+        //then
+        String expected = TestCertificateProvider.getExpectedPemCertificateAsString();
+        assertThat(certificateTransformed).isEqualTo(expected);
+    }
+
+    @Test
+    void fileNotContainsPemCertificateShouldReturnTrueIfFileNotContainsCertificate()
+        throws TruststoreDataOperationException {
+        //given
+        File emptyPemFile = TestCertificateProvider.getEmptyPemFile();
+        PemTruststore pemCertificate = new PemTruststore(emptyPemFile);
+        //when//then
+        assertThat(pemCertificate.isFileWithoutPemCertificate()).isTrue();
+    }
+
+    @Test
+    void fileNotContainsPemCertificateShouldReturnFalseIfFileContainsCertificate()
+        throws TruststoreDataOperationException {
+        //given
+        File notEmptyPemFile = TestCertificateProvider.getNotEmptyPemFile();
+        PemTruststore pemCertificate = new PemTruststore(notEmptyPemFile);
+
+        //when//then
+        assertThat(pemCertificate.isFileWithoutPemCertificate()).isFalse();
+    }
+
+    @Test
+    void privateKeyIsSkippedWhileReadingCertificates() throws ExitableException {
+        //given
+        File pemTruststoreFile = TestCertificateProvider.getPemWithPrivateKeyFile();
+        PemTruststore pemCertificate = new PemTruststore(pemTruststoreFile);
+
+        //when
+        List<CertificateWithAlias> certificate = pemCertificate.getCertificates();
+
+        //then
+        assertThat(certificate).hasSize(EXPECTED_ONE);
+    }
+
+    private List<Certificate> unWrapCertificate(List<CertificateWithAlias> certificateWithAliases) {
+        return certificateWithAliases
+            .stream()
+            .map(CertificateWithAlias::getCertificate)
+            .collect(Collectors.toList());
+    }
+
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/TestCertificateProvider.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/TestCertificateProvider.java
new file mode 100644
index 00000000..f32e09ce
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/TestCertificateProvider.java
@@ -0,0 +1,152 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.merger.model;
+
+import static org.onap.oom.certservice.postprocessor.api.CertificateConstants.JKS_TYPE;
+import static org.onap.oom.certservice.postprocessor.api.CertificateConstants.PKCS12_TYPE;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardCopyOption;
+import org.onap.oom.certservice.postprocessor.merger.exception.KeystoreInstanceException;
+import org.onap.oom.certservice.postprocessor.merger.exception.LoadTruststoreException;
+import org.onap.oom.certservice.postprocessor.merger.exception.PasswordReaderException;
+
+public final class TestCertificateProvider {
+
+    public static final String SAMPLE_P12_TRUSTSTORE_FILE_PATH = "src/test/resources/truststore-p12.p12";
+    public static final String SAMPLE_P12_TRUSTSTORE_PASSWORD_PATH = "src/test/resources/truststore-p12.pass";
+    public static final String TMP_P12_TRUSTSTORE_FILE_PATH = "src/test/resources/tmp-truststore-p12.p12";
+
+    public static final String SAMPLE_P12_KEYSTORE_FILE_PATH = "src/test/resources/keystore.p12";
+    public static final String SAMPLE_P12_KEYSTORE_PASSWORD_PATH = "src/test/resources/keystore.pass";
+
+    public static final String SAMPLE_JKS_TRUSTSTORE_FILE_PATH = "src/test/resources/truststore-jks.jks";
+    public static final String SAMPLE_JKS_TRUSTSTORE_UNIQUE_ALIAS_FILE_PATH = "src/test/resources/truststore-jks-uniq.jks";
+    public static final String SAMPLE_JKS_TRUSTSTORE_PASSWORD_PATH = "src/test/resources/truststore-jks.pass";
+    public static final String TMP_JKS_TRUSTSTORE_FILE_PATH = "src/test/resources/tmp-truststore-jks.jks";
+
+    public static final String SAMPLE_PEM_TRUSTSTORE_FILE_PATH = "src/test/resources/truststore.pem";
+    public static final String EMPTY_PEM_TRUSTSTORE_FILE_PATH = "src/test/resources/empty-truststore.pem";
+    public static final String TMP_PEM_TRUSTSTORE_FILE_PATH = "src/test/resources/tmp-truststore.pem";
+    public static final String SAMPLE_PEM_TRUSTSTORE_WITH_PRIVATE_KEY_FILE_PATH = "src/test/resources/truststore-with-private-key.pem";
+
+    public static final String PEM_FILE_PATH = "src/test/resources/truststore.pem";
+    public static final String PEM_BACKUP_FILE_PATH = "src/test/resources/truststore.pem.bak";
+
+    private TestCertificateProvider() {
+    }
+
+    public static Truststore getSampleP12Truststore()
+        throws LoadTruststoreException, KeystoreInstanceException, PasswordReaderException {
+        return createJavaTruststore(SAMPLE_P12_TRUSTSTORE_FILE_PATH, SAMPLE_P12_TRUSTSTORE_PASSWORD_PATH, PKCS12_TYPE);
+    }
+
+    public static Truststore getSampleP12Keystore()
+        throws LoadTruststoreException, KeystoreInstanceException, PasswordReaderException {
+        return createJavaTruststore(SAMPLE_P12_KEYSTORE_FILE_PATH, SAMPLE_P12_KEYSTORE_PASSWORD_PATH, PKCS12_TYPE);
+    }
+
+    public static Truststore createTmpP12TruststoreFile()
+        throws IOException, LoadTruststoreException, KeystoreInstanceException, PasswordReaderException {
+        copyFile(SAMPLE_P12_TRUSTSTORE_FILE_PATH, TMP_P12_TRUSTSTORE_FILE_PATH);
+        return createJavaTruststore(TMP_P12_TRUSTSTORE_FILE_PATH, SAMPLE_P12_TRUSTSTORE_PASSWORD_PATH, PKCS12_TYPE);
+    }
+
+    public static Truststore getSamplePemTruststoreFile() {
+        return getPemTruststoreInstance(SAMPLE_PEM_TRUSTSTORE_FILE_PATH);
+    }
+
+    public static Truststore createEmptyTmpPemTruststoreFile()
+        throws IOException {
+        copyFile(EMPTY_PEM_TRUSTSTORE_FILE_PATH, TMP_PEM_TRUSTSTORE_FILE_PATH);
+        return getPemTruststoreInstance(TMP_PEM_TRUSTSTORE_FILE_PATH);
+    }
+
+    public static Truststore createTmpPemTruststoreFile()
+        throws IOException {
+        copyFile(SAMPLE_PEM_TRUSTSTORE_FILE_PATH, TMP_PEM_TRUSTSTORE_FILE_PATH);
+        return getPemTruststoreInstance(TMP_PEM_TRUSTSTORE_FILE_PATH);
+    }
+
+    public static String getExpectedPemCertificateAsString() throws IOException {
+        Path samplePemFilePath = Paths.get(SAMPLE_PEM_TRUSTSTORE_FILE_PATH);
+        return Files.readString(samplePemFilePath);
+    }
+
+    public static Truststore getSampleJksTruststoreFile()
+        throws LoadTruststoreException, KeystoreInstanceException, PasswordReaderException {
+        return createJavaTruststore(SAMPLE_JKS_TRUSTSTORE_FILE_PATH, SAMPLE_JKS_TRUSTSTORE_PASSWORD_PATH, JKS_TYPE);
+    }
+
+    public static Truststore getSampleJksTruststoreFileWithUniqueAlias()
+        throws LoadTruststoreException, KeystoreInstanceException, PasswordReaderException {
+        return createJavaTruststore(SAMPLE_JKS_TRUSTSTORE_UNIQUE_ALIAS_FILE_PATH, SAMPLE_JKS_TRUSTSTORE_PASSWORD_PATH,
+            JKS_TYPE);
+    }
+
+    public static Truststore createTmpJksTruststoreFileWithUniqAlias()
+        throws IOException, LoadTruststoreException, KeystoreInstanceException, PasswordReaderException {
+        copyFile(SAMPLE_JKS_TRUSTSTORE_UNIQUE_ALIAS_FILE_PATH, TMP_JKS_TRUSTSTORE_FILE_PATH);
+        return createJavaTruststore(TMP_JKS_TRUSTSTORE_FILE_PATH, SAMPLE_JKS_TRUSTSTORE_PASSWORD_PATH, JKS_TYPE);
+    }
+
+    public static File getEmptyPemFile() {
+        return getFile(EMPTY_PEM_TRUSTSTORE_FILE_PATH);
+    }
+
+    public static File getNotEmptyPemFile() {
+        return getFile(SAMPLE_PEM_TRUSTSTORE_FILE_PATH);
+    }
+
+    public static File getPemWithPrivateKeyFile() {
+        return getFile(SAMPLE_PEM_TRUSTSTORE_WITH_PRIVATE_KEY_FILE_PATH);
+    }
+
+    public static void removeTemporaryFiles() throws IOException {
+        Files.deleteIfExists(Paths.get(TMP_PEM_TRUSTSTORE_FILE_PATH));
+        Files.deleteIfExists(Paths.get(TMP_JKS_TRUSTSTORE_FILE_PATH));
+        Files.deleteIfExists(Paths.get(TMP_P12_TRUSTSTORE_FILE_PATH));
+        Files.deleteIfExists(Paths.get(PEM_BACKUP_FILE_PATH));
+    }
+
+    private static Truststore createJavaTruststore(String filePath, String password, String instanceType)
+        throws LoadTruststoreException, KeystoreInstanceException, PasswordReaderException {
+        File certFile = getFile(filePath);
+        return JavaTruststoreFactory.create(certFile, password, instanceType);
+    }
+
+    private static Truststore getPemTruststoreInstance(
+        String tmpPemTruststoreFilePath) {
+        File file = getFile(tmpPemTruststoreFilePath);
+        return new PemTruststore(file);
+    }
+
+    private static void copyFile(String sourcePath, String destPath) throws IOException {
+        Files.copy(Paths.get(sourcePath), Paths.get(destPath), StandardCopyOption.REPLACE_EXISTING);
+    }
+
+    private static File getFile(String path) {
+        return new File(path);
+    }
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/TruststoreFactoryTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/TruststoreFactoryTest.java
new file mode 100644
index 00000000..42bf533a
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/TruststoreFactoryTest.java
@@ -0,0 +1,109 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+
+package org.onap.oom.certservice.postprocessor.merger.model;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.onap.oom.certservice.postprocessor.merger.exception.KeystoreInstanceException;
+import org.onap.oom.certservice.postprocessor.merger.exception.LoadTruststoreException;
+import org.onap.oom.certservice.postprocessor.merger.exception.PasswordReaderException;
+import org.onap.oom.certservice.postprocessor.merger.exception.TruststoreFileFactoryException;
+
+@ExtendWith(MockitoExtension.class)
+class TruststoreFactoryTest {
+
+    private static final String TRUSTSTORE_JKS_PATH = "src/test/resources/truststore-jks.jks";
+    private static final String TRUSTSTORE_JKS_PASS_PATH = "src/test/resources/truststore-jks.pass";
+    private static final String TRUSTSTORE_P12_PATH = "src/test/resources/truststore-p12.p12";
+    private static final String TRUSTSTORE_P12_PASS_PATH = "src/test/resources/truststore-p12.pass";
+    private static final String TRUSTSTORE_PEM_PATH = "src/test/resources/truststore.pem";
+    private static final String EMPTY_PASS_PATH = "";
+    private static final String TRUSTSTORE_UNKNOWN_EXTENSION_PATH = "src/test/resources/truststore-jks.unknown";
+    private static final String NON_EXISTING_TRUSTSTORE_PATH = "src/test/resources/non-existing-truststore.jks";
+
+    @Test
+    void shouldReturnCorrectJksTruststoreForJksFile()
+        throws LoadTruststoreException, PasswordReaderException, TruststoreFileFactoryException, KeystoreInstanceException {
+        //given, when
+        Truststore truststore = TruststoreFactory
+            .create(TRUSTSTORE_JKS_PATH, TRUSTSTORE_JKS_PASS_PATH);
+
+        //then
+        assertThat(truststore).isInstanceOf(Truststore.class);
+    }
+
+    @Test
+    void shouldReturnCorrectP12TruststoreForP12File()
+        throws LoadTruststoreException, PasswordReaderException, TruststoreFileFactoryException, KeystoreInstanceException {
+        //given, when
+        Truststore truststore = TruststoreFactory
+            .create(TRUSTSTORE_P12_PATH, TRUSTSTORE_P12_PASS_PATH);
+
+        //then
+        assertThat(truststore).isInstanceOf(Truststore.class);
+    }
+
+    @Test
+    void shouldReturnCorrectPemTruststoreForPemFile()
+        throws LoadTruststoreException, PasswordReaderException, TruststoreFileFactoryException, KeystoreInstanceException {
+        //given, when
+        Truststore truststore = TruststoreFactory
+            .create(TRUSTSTORE_PEM_PATH,
+                EMPTY_PASS_PATH);
+
+        //then
+        assertThat(truststore).isInstanceOf(Truststore.class);
+    }
+
+    @Test
+    void shouldThrowExceptionForInvalidP12PassPath() {
+        assertThatExceptionOfType(PasswordReaderException.class).isThrownBy(
+            () -> TruststoreFactory.create(TRUSTSTORE_P12_PATH, EMPTY_PASS_PATH)
+        );
+    }
+
+    @Test
+    void shouldThrowExceptionForInvalidJksPassPath() {
+        assertThatExceptionOfType(PasswordReaderException.class).isThrownBy(
+            () -> TruststoreFactory.create(TRUSTSTORE_JKS_PATH, EMPTY_PASS_PATH)
+        );
+    }
+
+    @Test
+    void shouldThrowExceptionForUnknownTruststoreExtension() {
+        assertThatExceptionOfType(TruststoreFileFactoryException.class).isThrownBy(
+            () -> TruststoreFactory
+                .create(TRUSTSTORE_UNKNOWN_EXTENSION_PATH, TRUSTSTORE_JKS_PASS_PATH)
+        );
+    }
+
+    @Test
+    void shouldThrowExceptionForNonExistingTruststoreFile() {
+        assertThatExceptionOfType(TruststoreFileFactoryException.class).isThrownBy(
+            () -> TruststoreFactory.create(NON_EXISTING_TRUSTSTORE_PATH, TRUSTSTORE_JKS_PASS_PATH)
+        );
+    }
+
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/TruststoreTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/TruststoreTest.java
new file mode 100644
index 00000000..8ef148a8
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/TruststoreTest.java
@@ -0,0 +1,206 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.merger.model;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+import static org.onap.oom.certservice.postprocessor.api.CertificateConstants.X_509_CERTIFICATE;
+import static org.onap.oom.certservice.postprocessor.merger.model.TestCertificateProvider.PEM_BACKUP_FILE_PATH;
+
+import java.io.File;
+import java.io.IOException;
+import java.security.cert.Certificate;
+import java.security.cert.CertificateEncodingException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Stream;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.onap.oom.certservice.postprocessor.api.CertificateConstants;
+import org.onap.oom.certservice.postprocessor.api.ExitableException;
+import org.onap.oom.certservice.postprocessor.merger.exception.CreateBackupException;
+import org.onap.oom.certservice.postprocessor.merger.exception.KeystoreInstanceException;
+import org.onap.oom.certservice.postprocessor.merger.exception.LoadTruststoreException;
+import org.onap.oom.certservice.postprocessor.merger.exception.MissingTruststoreException;
+import org.onap.oom.certservice.postprocessor.merger.exception.PasswordReaderException;
+import org.onap.oom.certservice.postprocessor.merger.exception.TruststoreDataOperationException;
+import org.onap.oom.certservice.postprocessor.merger.model.certificate.CertificateWithAlias;
+import org.onap.oom.certservice.postprocessor.merger.model.certificate.CertificateWithAliasFactory;
+
+class TruststoreTest {
+
+    private static final String BACKUP_EXTENSION = ".bak";
+
+    private static final int EXPECTED_ONE = 1;
+    public static final int EXPECTED_THREE = 3;
+    public static final int FIRST_ELEMENT = 0;
+
+    private final CertificateWithAliasFactory factory = new CertificateWithAliasFactory();
+
+    @Test
+    void createBackupShouldCreateFileWithExtension() throws CreateBackupException {
+        //given
+        File pemFile = new File(TestCertificateProvider.PEM_FILE_PATH);
+        Truststore truststore = new PemTruststore(pemFile);
+        //when
+        truststore.createBackup();
+
+        //then
+        File backupFile = new File(PEM_BACKUP_FILE_PATH);
+        assertThat(backupFile.getName().endsWith(BACKUP_EXTENSION)).isTrue();
+        assertThat(backupFile.isFile()).isTrue();
+    }
+
+    @ParameterizedTest
+    @MethodSource("truststoreProvider")
+    void truststoreShouldReadCertificatesFromFile(Truststore truststore) throws ExitableException {
+        //when
+
+        List<CertificateWithAlias> certificates = truststore.getCertificates();
+        Certificate certificate = certificates.get(FIRST_ELEMENT).getCertificate();
+
+        //then
+        assertThat(certificates).hasSize(EXPECTED_ONE);
+        assertThat(certificate.getType()).isEqualTo(X_509_CERTIFICATE);
+    }
+
+    @Test
+    void jksTruststoreShouldAddDifferentCertificates() throws Exception {
+        //given
+        Truststore jksTruststore = TestCertificateProvider.createTmpJksTruststoreFileWithUniqAlias();
+
+        List<CertificateWithAlias> certificateFromP12 = TestCertificateProvider.getSampleP12Truststore()
+            .getCertificates();
+
+        List<CertificateWithAlias> certificateFromPem = TestCertificateProvider
+            .getSamplePemTruststoreFile().getCertificates();
+
+        //when
+
+        jksTruststore.addCertificates(certificateFromP12);
+
+        jksTruststore.addCertificates(certificateFromPem);
+
+        jksTruststore.saveFile();
+
+        //then
+
+        assertThat(jksTruststore.getCertificates()).hasSize(EXPECTED_THREE);
+    }
+
+    @Test
+    void p12TruststoreShouldAddDifferentCertificates() throws Exception {
+        //given
+        Truststore p12Truststore = TestCertificateProvider.createTmpP12TruststoreFile();
+
+        List<CertificateWithAlias> certificateFromJks = TestCertificateProvider
+            .getSampleJksTruststoreFileWithUniqueAlias().getCertificates();
+
+        List<CertificateWithAlias> certificateFromPem = TestCertificateProvider
+            .getSamplePemTruststoreFile().getCertificates();
+
+        //when
+
+        p12Truststore.addCertificates(certificateFromJks);
+        p12Truststore.addCertificates(certificateFromPem);
+        p12Truststore.saveFile();
+
+        //then
+
+        assertThat(p12Truststore.getCertificates()).hasSize(EXPECTED_THREE);
+    }
+
+    @Test
+    void pemTruststoreShouldAddDifferentCertificates() throws IOException, ExitableException {
+        //given
+        Truststore pemTruststore = TestCertificateProvider
+            .createTmpPemTruststoreFile();
+
+        List<CertificateWithAlias> certificateFromJks = TestCertificateProvider
+            .getSampleJksTruststoreFileWithUniqueAlias().getCertificates();
+
+        List<CertificateWithAlias> certificateFromP12 = TestCertificateProvider.getSampleP12Truststore()
+            .getCertificates();
+
+        //when
+
+        pemTruststore.addCertificates(certificateFromJks);
+
+        pemTruststore.addCertificates(certificateFromP12);
+
+        pemTruststore.saveFile();
+
+        //then
+
+        List<CertificateWithAlias> addedCertificates = pemTruststore.getCertificates();
+        Certificate certificate = addedCertificates.get(FIRST_ELEMENT).getCertificate();
+
+        assertThat(pemTruststore.getCertificates()).hasSize(EXPECTED_THREE);
+        assertThat(certificate.getType()).isEqualTo(X_509_CERTIFICATE);
+    }
+
+    @Test
+    void shouldThrowExceptionWhenFileNotContainsCertificate() throws IOException {
+        //given
+        Truststore tmpPemTruststoreFile = TestCertificateProvider
+            .createEmptyTmpPemTruststoreFile();
+        //when//then
+        assertThatExceptionOfType(MissingTruststoreException.class)
+            .isThrownBy(() -> tmpPemTruststoreFile.getCertificates());
+    }
+
+    @Test
+    void shouldThrowExceptionWhenCannotConvertCertificateToPem() throws Exception {
+        //given
+        Truststore pemTruststore = TestCertificateProvider.createTmpPemTruststoreFile();
+        Certificate certificate = mock(Certificate.class);
+
+        when(certificate.getEncoded()).thenThrow(new CertificateEncodingException());
+
+        List<CertificateWithAlias> certificateFromPem = new ArrayList<>();
+        certificateFromPem.add(factory.createPemCertificate(certificate));
+
+        pemTruststore.addCertificates(certificateFromPem);
+
+        //when //then
+        assertThatExceptionOfType(TruststoreDataOperationException.class)
+            .isThrownBy(() -> pemTruststore.saveFile());
+    }
+
+    @AfterEach
+    void removeTemporaryFiles() throws IOException {
+        TestCertificateProvider.removeTemporaryFiles();
+    }
+
+    private static Stream<Arguments> truststoreProvider()
+        throws LoadTruststoreException, KeystoreInstanceException, PasswordReaderException {
+        return Stream.of(
+            Arguments.of(TestCertificateProvider.getSampleJksTruststoreFile()),
+            Arguments.of(TestCertificateProvider.getSampleP12Truststore()),
+            Arguments.of(TestCertificateProvider.getSamplePemTruststoreFile())
+        );
+    }
+
+}
diff --git a/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/certificate/PemAliasGeneratorTest.java b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/certificate/PemAliasGeneratorTest.java
new file mode 100644
index 00000000..03989f6f
--- /dev/null
+++ b/certServicePostProcessor/src/test/java/org/onap/oom/certservice/postprocessor/merger/model/certificate/PemAliasGeneratorTest.java
@@ -0,0 +1,58 @@
+/*============LICENSE_START=======================================================
+ * oom-truststore-merger
+ * ================================================================================
+ * Copyright (C) 2020 Nokia. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.oom.certservice.postprocessor.merger.model.certificate;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.HashSet;
+import java.util.Set;
+import org.junit.jupiter.api.Test;
+
+class PemAliasGeneratorTest {
+
+    private static final String PREFIX_ALIAS_NAME = "pem-trusted-certificate-";
+    static final int GENERATED_ALIASES_NUMBER = 100;
+
+    @Test
+    void aliasHasPemPrefix() {
+        //given
+        PemAliasGenerator pemAliasGenerator = PemAliasGenerator.getInstance();
+        //when
+        String alias = pemAliasGenerator.getAlias();
+        //then
+        assertThat(alias).contains(PREFIX_ALIAS_NAME);
+    }
+
+    @Test
+    void generatedAliasesHaveUniqNames() {
+        //given
+        PemAliasGenerator pemAliasGenerator = PemAliasGenerator.getInstance();
+        Set<String> aliases = new HashSet<>();
+
+        //when
+        for (int i = 0; i < GENERATED_ALIASES_NUMBER; i++) {
+            aliases.add(pemAliasGenerator.getAlias());
+        }
+
+        //then
+        assertThat(aliases).hasSize(GENERATED_ALIASES_NUMBER);
+    }
+
+}
diff --git a/certServicePostProcessor/src/test/resources/empty-truststore.pem b/certServicePostProcessor/src/test/resources/empty-truststore.pem
new file mode 100644
index 00000000..8b137891
--- /dev/null
+++ b/certServicePostProcessor/src/test/resources/empty-truststore.pem
@@ -0,0 +1 @@
+
diff --git a/certServicePostProcessor/src/test/resources/keystore.p12 b/certServicePostProcessor/src/test/resources/keystore.p12
new file mode 100644
index 00000000..bc047a98
--- /dev/null
+++ b/certServicePostProcessor/src/test/resources/keystore.p12
diff --git a/certServicePostProcessor/src/test/resources/keystore.pass b/certServicePostProcessor/src/test/resources/keystore.pass
new file mode 100644
index 00000000..665ff8e6
--- /dev/null
+++ b/certServicePostProcessor/src/test/resources/keystore.pass
@@ -0,0 +1 @@
+Foh49MJNYI7S_pEzE9gvUDSu
\ No newline at end of file
diff --git a/certServicePostProcessor/src/test/resources/truststore-jks-uniq.jks b/certServicePostProcessor/src/test/resources/truststore-jks-uniq.jks
new file mode 100644
index 00000000..76ce8bc4
--- /dev/null
+++ b/certServicePostProcessor/src/test/resources/truststore-jks-uniq.jks
diff --git a/certServicePostProcessor/src/test/resources/truststore-jks.jks b/certServicePostProcessor/src/test/resources/truststore-jks.jks
new file mode 100644
index 00000000..38229811
--- /dev/null
+++ b/certServicePostProcessor/src/test/resources/truststore-jks.jks
diff --git a/certServicePostProcessor/src/test/resources/truststore-jks.pass b/certServicePostProcessor/src/test/resources/truststore-jks.pass
new file mode 100644
index 00000000..7426fd4d
--- /dev/null
+++ b/certServicePostProcessor/src/test/resources/truststore-jks.pass
@@ -0,0 +1 @@
+EOyuFbuYDyq_EhpboM72RHua
\ No newline at end of file
diff --git a/certServicePostProcessor/src/test/resources/truststore-p12.p12 b/certServicePostProcessor/src/test/resources/truststore-p12.p12
new file mode 100644
index 00000000..0fa8aecc
--- /dev/null
+++ b/certServicePostProcessor/src/test/resources/truststore-p12.p12
diff --git a/certServicePostProcessor/src/test/resources/truststore-p12.pass b/certServicePostProcessor/src/test/resources/truststore-p12.pass
new file mode 100644
index 00000000..86cc5aac
--- /dev/null
+++ b/certServicePostProcessor/src/test/resources/truststore-p12.pass
@@ -0,0 +1 @@
+88y9v5D8H3SG6bZWRVHDfOAo
\ No newline at end of file
diff --git a/certServicePostProcessor/src/test/resources/truststore-with-private-key.pem b/certServicePostProcessor/src/test/resources/truststore-with-private-key.pem
new file mode 100644
index 00000000..95179062
--- /dev/null
+++ b/certServicePostProcessor/src/test/resources/truststore-with-private-key.pem
@@ -0,0 +1,56 @@
+-----BEGIN CERTIFICATE-----
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+-----BEGIN RSA PRIVATE KEY-----
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+-----END RSA PRIVATE KEY-----
diff --git a/certServicePostProcessor/src/test/resources/truststore.pem b/certServicePostProcessor/src/test/resources/truststore.pem
new file mode 100644
index 00000000..3268e3a6
--- /dev/null
+++ b/certServicePostProcessor/src/test/resources/truststore.pem
@@ -0,0 +1,28 @@
+-----BEGIN CERTIFICATE-----
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+-----END CERTIFICATE-----