Karma Spec Reporter

Installing karma-spec-reporter

Unlike progress, spec prints every describe()/it() description as it executes, indented to reflect nesting, with a checkmark or cross next to each spec's result. This makes it far easier to see exactly what a suite covers just from reading the output.

npm install --save-dev karma-spec-reporter

// karma.conf.js
config.set({
  reporters: ['spec']
});

// Example output:
// Calculator
//   ✓ adds two numbers
//   ✗ throws on invalid input
//     Expected function to throw an error.

The indentation mirrors nested describe() blocks, making the test suite's structure visible directly in the terminal.

Configuring Display Options

config.set({
  reporters: ['spec'],
  specReporter: {
    maxLogLines: 5,
    suppressErrorSummary: false,
    suppressFailed: false,
    suppressPassed: false,
    suppressSkipped: true,
    showSpecTiming: true,
    failFast: false
  }
});

• suppressPassed: true shows only failures, useful for very large, mostly-passing suites.
• showSpecTiming: true prints per-spec duration, helpful for spotting unexpectedly slow tests.
• suppressSkipped: true (a common default) hides xit/xdescribe skipped specs from cluttering output.
• maxLogLines caps how many lines of a failure's stack trace print before truncating.

specReporter Options Cheat Sheet

The most useful display tuning options.

spec vs. progress: Choosing Between Them

spec trades output volume for visibility — it's the better choice while actively writing tests locally, since seeing every spec description helps confirm you've covered what you intended. For CI logs on a very large suite, the extra volume can sometimes be more noise than signal, in which case progress (or spec with suppressPassed: true) may be preferable.

Combining spec with a File-Writing Reporter

spec is purely a terminal reporter — it prints nothing to a file. Pairing it with junit or html gives you both a readable live run and a durable, machine-consumable artifact.

reporters: ['spec', 'junit'],
junitReporter: { outputDir: 'reports/junit' }

Common Mistakes

• Using spec on an enormous suite in CI without suppressPassed, flooding logs unnecessarily.
• Forgetting spec writes nothing to disk, and needing a separate reporter for CI artifacts anyway.
• Not enabling showSpecTiming when hunting for a specific slow test dragging down suite run time.
• Assuming failFast is Karma's default behavior — it must be explicitly enabled on specReporter.

Key Takeaways

• karma-spec-reporter prints every spec description in a readable, indented hierarchy.
• It's ideal for local development, where seeing exactly what ran (and its result) is valuable.
• specReporter options let you suppress passed/skipped specs and show per-spec timing.
• Pair spec with a file-writing reporter like junit for a complete local + CI reporting setup.