0000-pluggableLintTestGenerator.md

• Start Date: 2015-05-19
• RFC PR: (leave this empty)
• ember-cli Issue: (leave this empty)

Summary

Provide a unified API for linting for complete choice of testing framework and linting platform.

Motivation

Allow user to have full control over what testing language and what linter they prefer. Currently ember-cli is tied into using JSHint always rather than being fully agnostic.

Detailed design

In ember-cli addons main file.

Expose a test generator API for the linting addon to call:

  lintTree: function(type, tree) {
    return jshintTrees(tree, {
      jshintrcPath: this.jshintrc.tests,
      description: 'JSHint ' + type,
      testGenerator: this.testGenerator
    });
  }

Expose a new test Generator hook that would return the lint errors transformed to the test language (This will likely be in the testing framework addon):

  testGenerator: function (relativePath, errors) {
    if (errors) {
      errors = "\\n" + this.escapeErrorString(errors);
    } else {
      errors = "";
    }

    return "describe('JSHint - " + relativePath + "', function(){\n" +
      "it('should pass jshint', function() { \n" +
      "  expect(" + !!errors + ", '" + relativePath + " should pass jshint." + errors + "').to.be.ok(); \n" +
      "})});\n";
  }

Drawbacks

• The API for all linters will restrict the API of testGenerator hook.
• Errors in the linter not returning the correct API will cause issues in outputting.

Alternatives

• Consider using native new Error for APIs into testGenerator.
• Consider using object instead of multiple arguments for testGenerator.
• Use blueprints instead of testGenerator.

Unresolved questions

• What would the best API be for testGenerator?
• How do we make ember handle multiple extensions of testGenerator?
• Should we trigger a fatal error if testGenerator doesn't receive the valid API usage?