villedemontreal / mocha-error-reporters

mocha-error-reporters includes the full error object as JSON in the test report when an error has some meaningful extra information.

(French version)

mocha-error-reporters

When a test fails due to an unexpected error, mocha-error-reporters appends the full error in JSON format to the test report.

Test report example

1 passing (5ms)
  1 failing

  1) Test Example
       Test with error:
     Error: Pow!
      at Context.it (test/testData/testExample.js:9:17)
  
  Full Error:
  {
    "additionnalAttribute": "The key to understand this bug",
    "name": "Error",
    "message": "Pow!",
    "stack": "Error: Pow!\n    at Context.it (test/testData/testExample.js:9:17)"
  }

Without mocha-error-reporters, the Full Error section would ne be present and it would be impossible to read additionnalAttribute which may be the key to understand this bug. All additionnal attributes (ex: inner error) will be fully serialized; thanks to the npm package serialize-error.

To Install

In your project, run this npm command:

npm install mocha-error-reporters --save-dev

Usage

Call mocha with:

mocha --require mocha-error-reporters --reporter=specWithFullErrors

mocha-error-reporters provides 8 reporters:

• specWithFullErrors
• minWithFullErrors
• dotWithFullErrors
• listWithFullErrors
• nyanWithFullErrors
• xUnitWithFullErrors
• progressWithFullErrors
• landingWithFullErrors

Custom reporters

Mocha allows you to define custom reporters.

The code snippet below shows how unexpected errors can be serialized in your custom reporters.

const { extendReporterWithFullErrors } = require('mocha-error-reporters');
const yourCustomReporter;
const yourCustomReporterWithFullErrors = extendReporterWithFullErrors(yourCustomReporter);

License

The source code of this project is distributed under the MIT License.

Contributing

See CONTRIBUTING.md.

Code of Conduct

Participation in this poject is governed by the Code of Conduct.

mocha-error-reporters's Issues

`extendReporterWithFullErrors` is incompatible with `mocha-junit-reporter`

Hey all! Firstly, thanks for the helpful util!

One note though is that in its current form, extendReporterWithFullErrors is incompatible with the popular mocha-junit-reporter. Since extendReporterWithFullErrors calls superReporter.call(this, runner, options); before calling withFullErrors, the JUnit reporter attaches its fail handler first which serializes the error to a string for the later-generated XML before addFullErrorIfMeaningful is ever called to modify error.stack.

I fixed this by adding the fail handler before calling the JUnit constructor:

junitWithFullErrors.js:

const { inherits } = require('util');
const addFullErrorIfMeaningful = require('mocha-error-reporters/lib/addFullErrorIfMeaningful');
const JUnitReporter = require('mocha-junit-reporter');

function JUnitReporterWithFullErrors(runner, options) {
  // `mocha-error-reporters` has a `extendReporterWithFullErrors` util but we manually pull in
  // `addFullErrorIfMeaningful` and extend the JUnit reporter in order to ensure that our
  // `.on('fail', ...)` is called before JUnit's `.on('fail', ...` so that the full error data is
  // appended to `error.stack` before JUnit serializes it to XML.
  runner.on('fail', (test, error) => addFullErrorIfMeaningful(error));
  JUnitReporter.call(this, runner, options);
}
inherits(JUnitReporterWithFullErrors, JUnitReporter);

module.exports = JUnitReporterWithFullErrors;