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