Apostrophe handling in CpsPathParser

Apostrophe is not currently handled correctly, and having apostrophe in
the xpath will lead to various errors.
For example, normalizing this xpath works:
  /path[@name="I'm quoted"] -> /path[@name='I\'m quoted']
However the resulting xpath will throw a PathParsingException if parsed!
(Thus path normalization is not idempotent.)

- Use '' for escaping apostrophe in single quoted leaf value,
  to comply with XPath standard (and use "" for escaping in ").
- Use Liquibase to make existing data comply with new rules.
- Leaf values in data leaves are now unescaped, e.g. "I'm quoted"
- Quoting is now consistent for leaf/text/contains conditions.

Issue-ID: CPS-1769
Signed-off-by: danielhanrahan <daniel.hanrahan@est.tech>
Change-Id: Iafc287f738254d7f99706c6bc548091c0ecd5aa0

1 files changed, 10 insertions, 4 deletions

diff --git a/cps-path-parser/src/main/antlr4/org/onap/cps/cpspath/parser/antlr4/CpsPath.g4 b/cps-path-parser/src/main/antlr4/org/onap/cps/cpspath/parser/antlr4/CpsPath.g4
index c88a822654..3aef120fed 100644
--- a/cps-path-parser/src/main/antlr4/org/onap/cps/cpspath/parser/antlr4/CpsPath.g4
+++ b/cps-path-parser/src/main/antlr4/org/onap/cps/cpspath/parser/antlr4/CpsPath.g4
@@ -1,6 +1,6 @@
 /*
  *  ============LICENSE_START=======================================================
- *  Copyright (C) 2021-2022 Nordix Foundation
+ *  Copyright (C) 2021-2023 Nordix Foundation
  *  Modifications Copyright (C) 2023 TechMahindra Ltd
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -19,6 +19,12 @@
  *  ============LICENSE_END=========================================================
  */
 
+/*
+ * Parser Rules
+ * Some of the parser rules below are inspired by
+ * https://github.com/antlr/grammars-v4/blob/master/xpath/xpath31/XPath31Parser.g4
+ */
+
 grammar CpsPath ;
 
 cpsPath : ( prefix | descendant | incorrectPrefix ) multipleLeafConditions? textFunctionCondition? containsFunctionCondition? ancestorAxis? invalidPostFix?;
@@ -60,7 +66,7 @@ invalidPostFix : (AT | CB | COLONCOLON | comparativeOperators ).+ ;
 /*
  * Lexer Rules
  * Most of the lexer rules below are inspired by
- * https://raw.githubusercontent.com/antlr/grammars-v4/master/xpath/xpath31/XPath31.g4
+ * https://github.com/antlr/grammars-v4/blob/master/xpath/xpath31/XPath31Lexer.g4
  */
 
 AT : '@' ;
@@ -89,9 +95,9 @@ IntegerLiteral : FragDigits ;
 // Add below type definitions for leafvalue comparision in https://jira.onap.org/browse/CPS-440
 DecimalLiteral : ('.' FragDigits) | (FragDigits '.' [0-9]*) ;
 DoubleLiteral : (('.' FragDigits) | (FragDigits ('.' [0-9]*)?)) [eE] [+-]? FragDigits ;
-StringLiteral : ('"' (FragEscapeQuot | ~[^"])*? '"') | ('\'' (FragEscapeApos | ~['])*? '\'') ;
+StringLiteral : '"' (~["] | FragEscapeQuot)* '"' | '\'' (~['] | FragEscapeApos)* '\'' ;
 fragment FragEscapeQuot : '""' ;
-fragment FragEscapeApos : '\'' ;
+fragment FragEscapeApos : '\'\'';
 fragment FragDigits : [0-9]+ ;
 
 QName  : FragQName ;