tape

What is tape?

Tape is a minimalist JavaScript testing framework for Node.js. It provides a simple and straightforward way to write tests for your code, focusing on simplicity and ease of use.

What are tape's main functionalities?

Basic Test

This feature allows you to write basic tests. The example demonstrates a simple test that checks if the sum of 1 and 1 equals 2.

const test = require('tape');

test('Basic test', function (t) {
  t.plan(1);
  t.equal(1 + 1, 2, '1 + 1 should equal 2');
});

Asynchronous Test

This feature allows you to write asynchronous tests. The example demonstrates a test that performs an assertion after a 1-second delay.

const test = require('tape');

test('Asynchronous test', function (t) {
  t.plan(1);
  setTimeout(function () {
    t.equal(1 + 1, 2, '1 + 1 should equal 2');
  }, 1000);
});

Nested Tests

This feature allows you to write nested tests. The example demonstrates a parent test containing a child test.

const test = require('tape');

test('Parent test', function (t) {
  t.test('Child test', function (st) {
    st.plan(1);
    st.equal(1 + 1, 2, '1 + 1 should equal 2');
  });
  t.end();
});

Other packages similar to tape

mocha

Mocha is a feature-rich JavaScript test framework running on Node.js and in the browser, making asynchronous testing simple and fun. It provides a variety of interfaces (e.g., BDD, TDD) and supports a wide range of reporters. Compared to Tape, Mocha is more feature-rich and flexible but also more complex.

jest

Jest is a delightful JavaScript testing framework with a focus on simplicity. It works out of the box for most JavaScript projects and includes features like snapshot testing and a built-in test runner. Compared to Tape, Jest is more opinionated and comes with more built-in features, making it easier to set up but less minimalistic.

ava

AVA is a test runner for Node.js with a concise API, detailed error output, and process isolation. It runs tests concurrently, which can lead to faster test execution. Compared to Tape, AVA is more modern and provides better support for ES6/ES7 features, but it may be less familiar to those used to traditional test runners.

README

tape

tap-producing test harness for node and browsers

browser compatibility

chrome, firefox, opera, safari, IE6, IE7, IE8, IE9

using browserify@1.16.5

example

var test = require('tape');

test('timing test', function (t) {
    t.plan(2);
    
    t.equal(typeof Date.now, 'function');
    var start = Date.now();
    
    setTimeout(function () {
        t.equal(Date.now() - start, 100);
    }, 100);
});

$ node example/timing.js
TAP version 13
# timing test
ok 1 should be equal
not ok 2 should be equal
  ---
    operator: equal
    expected: 100
    actual:   107
  ...

1..2
# tests 2
# pass  1
# fail  1

methods

The assertion methods in tape are heavily influenced or copied from the methods in node-tap.

var test = require('tape')

test(name, cb)

Create a new test with an optional name string. cb(t) fires with the new test object t once all preceeding tests have finished. Tests execute serially.

If you forget to t.plan() out how many assertions you are going to run and you don't call t.end() explicitly, your test will hang.

t.plan(n)

Declare that n assertions should be run. t.end() will be called automatically after the nth assertion. If there are any more assertions after the nth, or after t.end() is called, they will generate errors.

t.end()

Declare the end of a test explicitly.

t.fail(msg)

Generate a failing assertion with a message msg.

t.pass(msg)

Generate a passing assertion with a message msg.

t.skip(msg)

Generate an assertion that will be skipped over.

t.ok(value, msg)

Assert that value is truthy with an optional description message msg.

Aliases: t.true(), t.assert()

t.notOk(value, msg)

Assert that value is falsy with an optional description message msg.

Aliases: t.false(), t.notok()

t.error(err, msg)

Assert that err is falsy. If err is non-falsy, use its err.message as the description message.

Aliases: t.ifError(), t.ifErr(), t.iferror()

t.equal(a, b, msg)

Assert that a === b with an optional description msg.

Aliases: t.equals(), t.isEqual(), t.is(), t.strictEqual(), t.strictEquals()

t.notEqual(a, b, msg)

Assert that a !== b with an optional description msg.

Aliases: t.notEquals(), t.notStrictEqual(), t.notStrictEquals(), t.isNotEqual(), t.isNot(), t.not(), t.doesNotEqual(), t.isInequal()

t.deepEqual(a, b, msg)

Assert that a and b have the same structure and nested values using node's deepEqual() algorithm with an optional description msg.

Aliases: t.deepEquals(), t.isEquivalent(), t.looseEqual(), t.looseEquals(), t.same()

t.notDeepEqual(a, b, msg)

Assert that a and b do not have the same structure and nested values using node's deepEqual() algorithm with an optional description msg.

Aliases: t.notEquivalent(), t.notDeeply(), t.notSame(), t.isNotDeepEqual(), t.isNotDeeply(), t.isNotEquivalent(), t.isInequivalent()

t.throws(fn, expected, msg)

Assert that the function call fn() throws an exception.

t.doesNotThrow(fn, expected, msg)

Assert that the function call fn() does not throw an exception.

t.test(name, cb)

Create a subtest with a new test handle st from cb(st) inside the current test t. cb(st) will only fire when t finishes. Additional tests queued up after t will not be run until all subtests finish.

var htest = test.createHarness()

Create a new test harness instance, which is a function like test(), but with a new pending stack and test state.

By default the TAP output goes to process.stdout or console.log() if the environment doesn't have process.stdout. You can pipe the output to someplace else if you test.stream.pipe() to a destination stream on the first tick.

test.only(name, cb)

Like test(name, cb) except if you use .only this is the only test case that will run for the entire process, all other test cases using tape will be ignored

install

With npm do:

npm install tape

license

MIT

Changelog

v1.0.0 - 2013-05-03

Commits

• took out lots of complexity, refactoring 827b59d
• basic example finally works 2a59c49
• removing harness test, not sure why it's broken on 0.8 bd9e9a6
• nested test nearly works 7951747
• refactor exit logic 890382d
• fixed for the two example 0ac88b8
• use a createStream() function instead of .stream 6417cdc
• fix harness test fa706ae
• no longer getting already closed errors by tracking the number of running tests c9def14
• child ordering output is now correct 5544d26
• only test passes 4fbabba
• check for end and call ._exit() if unended ce0d62c
• fixed the many test, broke the exit test 72e34ad
• passing one more of the exit tests 5ec8f42
• nested test at least finishes now 6252fd2
• fix default harness going off unexpectedly b1c1d6a
• special case for exiting, all tests pass now 88de699
• passing the skip test 876930e
• update the tests to use createStream 9420e07
• check pause status before resuming 606b141
• nested example completely works a5e709e
• only the exported harness will be piped to the default stream 6df7fc0
• exit test completely passes f37d431
• fixed the nested test 4f05679
• getting further into the child ordering test 8a80302
• getting further into the child ordering test 365ceab
• update the harness test for createStream 5329dc6
• partial fix for v0.10 exiting early 78c7b77
• partly fixed the test name ordering issue c4dc7ac