ember-qunit-nice-errors

Because expected true, result false is not enough.

Gives message-less QUnit assertions a message: their own source text.

// you write
assert.ok(user.isActive);

// it compiles to
assert.ok(user.isActive, 'assert.ok(user.isActive)');

So a failure reports

assert.ok(user.isActive)

instead of

failed, expected argument to be truthy

Only assertions without a message are touched. Anything you wrote yourself is left alone.

Upgrading from v2? v3 is a Babel plugin rather than an ember-cli addon, and it needs one line of configuration — installing it is no longer enough. See MIGRATION.md.

Installation

pnpm add --save-dev ember-qunit-nice-errors

Then add it to your Babel config. This step is required — the plugin does nothing until you do.

Vite / Embroider

// babel.config.mjs
import qunitNiceErrors from 'ember-qunit-nice-errors';

export default {
  plugins: [
    qunitNiceErrors,
    // ...your other plugins
  ],
};

Classic ember-cli builds

// ember-cli-build.js
const app = new EmberApp(defaults, {
  babel: {
    plugins: [require.resolve('ember-qunit-nice-errors')],
  },
});

The same works in an addon's index.js and in an engine's ember-cli-build.js.

Compatibility

• @babel/core 7 or 8
• Node.js 22 or above

There is no longer an Ember version requirement — this is a plain Babel plugin. It works under Vite, Embroider and classic builds alike, and in any QUnit suite that runs through Babel.

Options

| option | type | default | meaning | | -------------------------- | --------------------------- | -------------------------------------- | ------------------------------------------------------------------------------------- | | include | RegExp \| string \| Array | [/-test\.(?:[cm]?[jt]sx?\|g[jt]s)$/] | Which filenames to transform. Replaces the default rather than extending it. | | exclude | RegExp \| string \| Array | — | Filenames to skip. Takes precedence over include. | | showFileInfo | boolean | false | Append at <path>:<line>:<column>, relative to Babel's cwd. | | completeExistingMessages | boolean | false | Also overwrite messages you wrote yourself. Off by default, and rarely what you want. |

Strings are compiled with new RegExp(...), so escape accordingly ('\\.spec\\.js$').

[
  'ember-qunit-nice-errors',
  {
    include: [/\.spec\.js$/],
    exclude: [/vendor/],
    showFileInfo: true,
  },
];

The default pattern is exported if you would rather extend it than replace it:

const { DEFAULT_INCLUDE } = require('ember-qunit-nice-errors');

['ember-qunit-nice-errors', { include: [...DEFAULT_INCLUDE, /\.spec\.js$/] }];

In v2 include and exclude were globs read from config/environment.js. They are now regular expressions passed as plugin options — see MIGRATION.md.

Which assertions

ok, notOk, equal, notEqual, strictEqual, notStrictEqual, deepEqual, notDeepEqual, propEqual, notPropEqual.

Assertions whose failure output is already descriptive — throws, step, verifySteps, expect, async, timeout — are deliberately left alone.

How it decides what is an assertion

It resolves the assert object through Babel's scope rather than matching the identifier by name. A call is transformed only when its object is the first parameter of a function passed to a QUnit test() — including QUnit.test, test.only, test.skip and test.todo.

That means:

• renamed parameters work — test('x', function (a) { a.ok(v); })
• arrow-function tests work — test('x', async (assert) => { … })
• an unrelated local called assert is not transformed
• an assert passed to hooks.beforeEach is not transformed, because it is not a test callback

The last two were gaps in v2, which tracked the most recently seen test() call textually and only matched FunctionExpression.

It is also idempotent: a call is only matched when its argument count says no message was passed, so re-running the transform cannot append twice.

Development

pnpm install
pnpm test          # node --test
pnpm run lint
pnpm run lint:fix

License

MIT