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diff --git a/vnfmarket/src/main/webapp/vnfmarket/node_modules/verror/README.md b/vnfmarket/src/main/webapp/vnfmarket/node_modules/verror/README.md deleted file mode 100644 index e9b54978..00000000 --- a/vnfmarket/src/main/webapp/vnfmarket/node_modules/verror/README.md +++ /dev/null @@ -1,120 +0,0 @@ -# verror: richer JavaScript errors - -This module provides two classes: VError, for accretive errors, and WError, for -wrapping errors. Both support printf-style error messages using extsprintf. - -## Printf-style errors - -At the most basic level, VError is just like JavaScript's Error class, but with -printf-style arguments: - - var verror = require('verror'); - - var opname = 'read'; - var err = new verror.VError('"%s" operation failed', opname); - console.log(err.message); - console.log(err.stack); - -This prints: - - "read" operation failed - "read" operation failed - at Object.<anonymous> (/Users/dap/node-verror/examples/varargs.js:4:11) - at Module._compile (module.js:449:26) - at Object.Module._extensions..js (module.js:467:10) - at Module.load (module.js:356:32) - at Function.Module._load (module.js:312:12) - at Module.runMain (module.js:492:10) - at process.startup.processNextTick.process._tickCallback (node.js:244:9) - - -## VError for accretive error messages - -More interestingly, you can use VError to build up an error describing what -happened at various levels in the stack. For example, suppose you have a -request handler that stats a file and fails if it doesn't exist: - - var fs = require('fs'); - var verror = require('verror'); - - function checkFile(filename, callback) { - fs.stat(filename, function (err) { - if (err) - /* Annotate the "stat" error with what we were doing. */ - return (callback(new verror.VError(err, - 'failed to check "%s"', filename))); - - /* ... */ - }); - } - - function handleRequest(filename, callback) { - checkFile('/nonexistent', function (err) { - if (err) { - /* Annotate the "checkFile" error with what we were doing. */ - return (callback(new verror.VError(err, 'request failed'))); - } - - /* ... */ - }); - } - - handleRequest('/nonexistent', function (err) { - if (err) - console.log(err.message); - /* ... */ - }); - -Since the file "/nonexistent" doesn't exist, this prints out: - - request failed: failed to check "/nonexistent": ENOENT, stat '/nonexistent' - -The idea here is that the lowest level (Node's "fs.stat" function) generates an -arbitrary error, and each higher level (request handler and stat callback) -creates a new VError that annotates the previous error with what it was doing, -so that the result is a clear message explaining what failed at each level. - -This plays nicely with extsprintf's "%r" specifier, which prints out a -Java-style stacktrace with the whole chain of exceptions: - - EXCEPTION: VError: request failed: failed to check "/nonexistent": ENOENT, stat '/nonexistent' - at /Users/dap/work/node-verror/examples/levels.js:21:21 - at /Users/dap/work/node-verror/examples/levels.js:9:12 - at Object.oncomplete (fs.js:297:15) - Caused by: EXCEPTION: VError: failed to check "/nonexistent": ENOENT, stat '/nonexistent' - at /Users/dap/work/node-verror/examples/levels.js:9:21 - at Object.oncomplete (fs.js:297:15) - Caused by: EXCEPTION: Error: Error: ENOENT, stat '/nonexistent' - - -## WError for wrapped errors - -Sometimes you don't want an Error's "message" field to include the details of -all of the low-level errors, but you still want to be able to get at them -programmatically. For example, in an HTTP server, you probably don't want to -spew all of the low-level errors back to the client, but you do want to include -them in the audit log entry for the request. In that case, you can use a -WError, which is created exactly like VError (and also supports both -printf-style arguments and an optional cause), but the resulting "message" only -contains the top-level error. It's also more verbose, including the class -associated with each error in the cause chain. Using the same example above, -but replacing the VError in handleRequest with WError, we get this output: - - request failed - -That's what we wanted -- just a high-level summary for the client. But we can -get the object's toString() for the full details: - - WError: request failed; caused by WError: failed to check "/nonexistent"; - caused by Error: ENOENT, stat '/nonexistent' - -# Contributing - -Contributions welcome. Code should be "make check" clean. To run "make check", -you'll need these tools: - -* https://github.com/davepacheco/jsstyle -* https://github.com/davepacheco/javascriptlint - -If you're changing something non-trivial or user-facing, you may want to submit -an issue first. |