528 lines
19 KiB
Markdown
528 lines
19 KiB
Markdown
# tape
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tap-producing test harness for node and browsers
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[![build status](https://secure.travis-ci.org/substack/tape.svg?branch=master)](http://travis-ci.org/substack/tape)
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![tape](https://web.archive.org/web/20170612184731if_/http://substack.net/images/tape_drive.png)
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# example
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``` js
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var test = require('tape');
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test('timing test', function (t) {
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t.plan(2);
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t.equal(typeof Date.now, 'function');
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var start = Date.now();
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setTimeout(function () {
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t.equal(Date.now() - start, 100);
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}, 100);
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});
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test('test using promises', async function (t) {
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const result = await someAsyncThing();
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t.ok(result);
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});
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```
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```
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$ node example/timing.js
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TAP version 13
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# timing test
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ok 1 should be strictly equal
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not ok 2 should be strictly equal
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---
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operator: equal
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expected: 100
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actual: 107
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...
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1..2
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# tests 2
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# pass 1
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# fail 1
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```
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# usage
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You always need to `require('tape')` in test files. You can run the tests by
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usual node means (`require('test-file.js')` or `node test-file.js`). You can
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also run tests using the `tape` binary to utilize globbing, on Windows for
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example:
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```sh
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$ tape tests/**/*.js
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```
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`tape`'s arguments are passed to the
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[`glob`](https://www.npmjs.com/package/glob) module. If you want `glob` to
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perform the expansion on a system where the shell performs such expansion, quote
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the arguments as necessary:
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```sh
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$ tape 'tests/**/*.js'
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$ tape "tests/**/*.js"
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```
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## Preloading modules
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Additionally, it is possible to make `tape` load one or more modules before running any tests, by using the `-r` or `--require` flag. Here's an example that loads [babel-register](http://babeljs.io/docs/usage/require/) before running any tests, to allow for JIT compilation:
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```sh
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$ tape -r babel-register tests/**/*.js
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```
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Depending on the module you're loading, you may be able to parameterize it using environment variables or auxiliary files. Babel, for instance, will load options from [`.babelrc`](http://babeljs.io/docs/usage/babelrc/) at runtime.
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The `-r` flag behaves exactly like node's `require`, and uses the same module resolution algorithm. This means that if you need to load local modules, you have to prepend their path with `./` or `../` accordingly.
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For example:
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```sh
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$ tape -r ./my/local/module tests/**/*.js
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```
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Please note that all modules loaded using the `-r` flag will run *before* any tests, regardless of when they are specified. For example, `tape -r a b -r c` will actually load `a` and `c` *before* loading `b`, since they are flagged as required modules.
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# things that go well with tape
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`tape` maintains a fairly minimal core. Additional features are usually added by using another module alongside `tape`.
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## pretty reporters
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The default TAP output is good for machines and humans that are robots.
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If you want a more colorful / pretty output there are lots of modules on npm
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that will output something pretty if you pipe TAP into them:
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- [tap-spec](https://github.com/scottcorgan/tap-spec)
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- [tap-dot](https://github.com/scottcorgan/tap-dot)
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- [faucet](https://github.com/substack/faucet)
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- [tap-bail](https://github.com/juliangruber/tap-bail)
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- [tap-browser-color](https://github.com/kirbysayshi/tap-browser-color)
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- [tap-json](https://github.com/gummesson/tap-json)
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- [tap-min](https://github.com/derhuerst/tap-min)
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- [tap-nyan](https://github.com/calvinmetcalf/tap-nyan)
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- [tap-pessimist](https://www.npmjs.org/package/tap-pessimist)
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- [tap-prettify](https://github.com/toolness/tap-prettify)
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- [colortape](https://github.com/shuhei/colortape)
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- [tap-xunit](https://github.com/aghassemi/tap-xunit)
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- [tap-difflet](https://github.com/namuol/tap-difflet)
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- [tape-dom](https://github.com/gritzko/tape-dom)
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- [tap-diff](https://github.com/axross/tap-diff)
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- [tap-notify](https://github.com/axross/tap-notify)
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- [tap-summary](https://github.com/zoubin/tap-summary)
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- [tap-markdown](https://github.com/Hypercubed/tap-markdown)
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- [tap-html](https://github.com/gabrielcsapo/tap-html)
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- [tap-react-browser](https://github.com/mcnuttandrew/tap-react-browser)
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- [tap-junit](https://github.com/dhershman1/tap-junit)
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- [tap-nyc](https://github.com/MegaArman/tap-nyc)
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- [tap-spec (emoji patch)](https://github.com/Sceat/tap-spec-emoji)
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- [tape-repeater](https://github.com/rgruesbeck/tape-repeater)
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- [tabe](https://github.com/Josenzo/tabe)
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To use them, try `node test/index.js | tap-spec` or pipe it into one
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of the modules of your choice!
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## uncaught exceptions
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By default, uncaught exceptions in your tests will not be intercepted, and will cause `tape` to crash. If you find this behavior undesirable, use [`tape-catch`](https://github.com/michaelrhodes/tape-catch) to report any exceptions as TAP errors.
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## other
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- CoffeeScript support with https://www.npmjs.com/package/coffeetape
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- ES6 support with https://www.npmjs.com/package/babel-tape-runner or https://www.npmjs.com/package/buble-tape-runner
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- Different test syntax with https://github.com/pguth/flip-tape (warning: mutates String.prototype)
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- Electron test runner with https://github.com/tundrax/electron-tap
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- Concurrency support with https://github.com/imsnif/mixed-tape
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- In-process reporting with https://github.com/DavidAnson/tape-player
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- Describe blocks with https://github.com/mattriley/tape-describe
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# methods
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The assertion methods in `tape` are heavily influenced or copied from the methods
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in [node-tap](https://github.com/isaacs/node-tap).
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```js
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var test = require('tape')
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```
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## test([name], [opts], cb)
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Create a new test with an optional `name` string and optional `opts` object.
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`cb(t)` fires with the new test object `t` once all preceding tests have
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finished. Tests execute serially.
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Available `opts` options are:
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- opts.skip = true/false. See test.skip.
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- opts.timeout = 500. Set a timeout for the test, after which it will fail. See test.timeoutAfter.
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- opts.objectPrintDepth = 5. Configure max depth of expected / actual object printing. Environmental variable `NODE_TAPE_OBJECT_PRINT_DEPTH` can set the desired default depth for all tests; locally-set values will take precedence.
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- opts.todo = true/false. Test will be allowed to fail.
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If you forget to `t.plan()` out how many assertions you are going to run and you don't call `t.end()` explicitly, or return a Promise that eventually settles, your test will hang.
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If `cb` returns a Promise, it will be implicitly awaited. If that promise rejects, the test will be failed; if it fulfills, the test will end. Explicitly calling `t.end()` while also returning a Promise that fulfills is an error.
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## test.skip([name], [opts], cb)
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Generate a new test that will be skipped over.
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## test.teardown(cb)
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Register a callback to run after the individual test has completed. Multiple registered teardown callbacks will run in order. Useful for undoing side effects, closing network connections, etc.
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## test.onFinish(fn)
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The onFinish hook will get invoked when ALL `tape` tests have finished right before `tape` is about to print the test summary.
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`fn` is called with no arguments, and its return value is ignored.
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## test.onFailure(fn)
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The onFailure hook will get invoked whenever any `tape` tests has failed.
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`fn` is called with no arguments, and its return value is ignored.
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## t.plan(n)
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Declare that `n` assertions should be run. `t.end()` will be called
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automatically after the `n`th assertion. If there are any more assertions after
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the `n`th, or after `t.end()` is called, they will generate errors.
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## t.end(err)
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Declare the end of a test explicitly. If `err` is passed in `t.end` will assert that it is falsy.
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Do not call `t.end()` if your test callback returns a Promise.
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## t.fail(msg)
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Generate a failing assertion with a message `msg`.
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## t.pass(msg)
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Generate a passing assertion with a message `msg`.
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## t.timeoutAfter(ms)
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Automatically timeout the test after X ms.
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## t.skip(msg)
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Generate an assertion that will be skipped over.
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## t.ok(value, msg)
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Assert that `value` is truthy with an optional description of the assertion `msg`.
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Aliases: `t.true()`, `t.assert()`
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## t.notOk(value, msg)
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Assert that `value` is falsy with an optional description of the assertion `msg`.
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Aliases: `t.false()`, `t.notok()`
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## t.error(err, msg)
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Assert that `err` is falsy. If `err` is non-falsy, use its `err.message` as the description message.
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Aliases: `t.ifError()`, `t.ifErr()`, `t.iferror()`
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## t.equal(actual, expected, msg)
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Assert that `Object.is(actual, expected)` with an optional description of the assertion `msg`.
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Aliases: `t.equals()`, `t.isEqual()`, `t.strictEqual()`, `t.strictEquals()`, `t.is()`
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## t.notEqual(actual, expected, msg)
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Assert that `!Object.is(actual, expected)` with an optional description of the assertion `msg`.
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Aliases: `t.notEquals()`, `t.isNotEqual()`, `t.doesNotEqual()`, `t.isInequal()`, `t.notStrictEqual()`, `t.notStrictEquals()`, `t.isNot()`, `t.not()`
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## t.looseEqual(actual, expected, msg)
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Assert that `actual == expected` with an optional description of the assertion `msg`.
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Aliases: `t.looseEquals()`
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## t.notLooseEqual(actual, expected, msg)
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Assert that `actual != expected` with an optional description of the assertion `msg`.
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Aliases: `t.notLooseEquals()`
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## t.deepEqual(actual, expected, msg)
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Assert that `actual` and `expected` have the same structure and nested values using
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[node's deepEqual() algorithm](https://github.com/substack/node-deep-equal)
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with strict comparisons (`===`) on leaf nodes and an optional description of the assertion `msg`.
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Aliases: `t.deepEquals()`, `t.isEquivalent()`, `t.same()`
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## t.notDeepEqual(actual, expected, msg)
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Assert that `actual` and `expected` do not have the same structure and nested values using
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[node's deepEqual() algorithm](https://github.com/substack/node-deep-equal)
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with strict comparisons (`===`) on leaf nodes and an optional description of the assertion `msg`.
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Aliases: `t.notDeepEquals`, `t.notEquivalent()`, `t.notDeeply()`, `t.notSame()`,
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`t.isNotDeepEqual()`, `t.isNotDeeply()`, `t.isNotEquivalent()`,
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`t.isInequivalent()`
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## t.deepLooseEqual(actual, expected, msg)
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Assert that `actual` and `expected` have the same structure and nested values using
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[node's deepEqual() algorithm](https://github.com/substack/node-deep-equal)
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with loose comparisons (`==`) on leaf nodes and an optional description of the assertion `msg`.
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## t.notDeepLooseEqual(actual, expected, msg)
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Assert that `actual` and `expected` do not have the same structure and nested values using
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[node's deepEqual() algorithm](https://github.com/substack/node-deep-equal)
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with loose comparisons (`==`) on leaf nodes and an optional description of the assertion `msg`.
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Aliases: `t.notLooseEqual()`, `t.notLooseEquals()`
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## t.throws(fn, expected, msg)
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Assert that the function call `fn()` throws an exception. `expected`, if present, must be a `RegExp`, `Function`, or `Object`. The `RegExp` matches the string representation of the exception, as generated by `err.toString()`. For example, if you set `expected` to `/user/`, the test will pass only if the string representation of the exception contains the word `user`. Any other exception will result in a failed test. The `Function` is the exception thrown (e.g. `Error`). `Object` in this case corresponds to a so-called validation object, in which each property is tested for strict deep equality. As an example, see the following two tests--each passes a validation object to `t.throws()` as the second parameter. The first test will pass, because all property values in the actual error object are deeply strictly equal to the property values in the validation object.
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```
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const err = new TypeError("Wrong value");
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err.code = 404;
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err.check = true;
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// Passing test.
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t.throws(
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() => {
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throw err;
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},
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{
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code: 404,
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check: true
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},
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"Test message."
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);
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```
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This next test will fail, because all property values in the actual error object are _not_ deeply strictly equal to the property values in the validation object.
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```
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const err = new TypeError("Wrong value");
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err.code = 404;
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err.check = "true";
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// Failing test.
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t.throws(
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() => {
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throw err;
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},
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{
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code: 404,
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check: true // This is not deeply strictly equal to err.check.
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},
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"Test message."
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);
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```
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This is very similar to how Node's `assert.throws()` method tests validation objects (please see the [Node _assert.throws()_ documentation](https://nodejs.org/api/assert.html#assert_assert_throws_fn_error_message) for more information).
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If `expected` is not of type `RegExp`, `Function`, or `Object`, or omitted entirely, any exception will result in a passed test. `msg` is an optional description of the assertion.
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Please note that the second parameter, `expected`, cannot be of type `string`. If a value of type `string` is provided for `expected`, then `t.throws(fn, expected, msg)` will execute, but the value of `expected` will be set to `undefined`, and the specified string will be set as the value for the `msg` parameter (regardless of what _actually_ passed as the third parameter). This can cause unexpected results, so please be mindful.
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## t.doesNotThrow(fn, expected, msg)
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Assert that the function call `fn()` does not throw an exception. `expected`, if present, limits what should not be thrown, and must be a `RegExp` or `Function`. The `RegExp` matches the string representation of the exception, as generated by `err.toString()`. For example, if you set `expected` to `/user/`, the test will fail only if the string representation of the exception contains the word `user`. Any other exception will result in a passed test. The `Function` is the exception thrown (e.g. `Error`). If `expected` is not of type `RegExp` or `Function`, or omitted entirely, any exception will result in a failed test. `msg` is an optional description of the assertion.
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Please note that the second parameter, `expected`, cannot be of type `string`. If a value of type `string` is provided for `expected`, then `t.doesNotThrows(fn, expected, msg)` will execute, but the value of `expected` will be set to `undefined`, and the specified string will be set as the value for the `msg` parameter (regardless of what _actually_ passed as the third parameter). This can cause unexpected results, so please be mindful.
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## t.test(name, [opts], cb)
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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.
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You may pass the same options that [`test()`](#testname-opts-cb) accepts.
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## t.comment(message)
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Print a message without breaking the tap output. (Useful when using e.g. `tap-colorize` where output is buffered & `console.log` will print in incorrect order vis-a-vis tap output.)
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Multiline output will be split by `\n` characters, and each one printed as a comment.
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## t.match(string, regexp, message)
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Assert that `string` matches the RegExp `regexp`. Will throw (not just fail) when the first two arguments are the wrong type.
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## t.doesNotMatch(string, regexp, message)
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Assert that `string` does not match the RegExp `regexp`. Will throw (not just fail) when the first two arguments are the wrong type.
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## var htest = test.createHarness()
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Create a new test harness instance, which is a function like `test()`, but with a new pending stack and test state.
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By default the TAP output goes to `console.log()`. You can pipe the output to someplace else if you `htest.createStream().pipe()` to a destination stream on the first tick.
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## test.only([name], [opts], cb)
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Like `test([name], [opts], 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.
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## var stream = test.createStream(opts)
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Create a stream of output, bypassing the default output stream that writes messages to `console.log()`. By default `stream` will be a text stream of TAP output, but you can get an object stream instead by setting `opts.objectMode` to `true`.
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### tap stream reporter
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You can create your own custom test reporter using this `createStream()` api:
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``` js
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var test = require('tape');
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var path = require('path');
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test.createStream().pipe(process.stdout);
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process.argv.slice(2).forEach(function (file) {
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require(path.resolve(file));
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});
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```
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You could substitute `process.stdout` for whatever other output stream you want, like a network connection or a file.
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Pass in test files to run as arguments:
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```sh
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$ node tap.js test/x.js test/y.js
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TAP version 13
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# (anonymous)
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not ok 1 should be strictly equal
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---
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operator: equal
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expected: "boop"
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actual: "beep"
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...
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# (anonymous)
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ok 2 should be strictly equal
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ok 3 (unnamed assert)
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# wheee
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ok 4 (unnamed assert)
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1..4
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# tests 4
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# pass 3
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# fail 1
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```
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### object stream reporter
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Here's how you can render an object stream instead of TAP:
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``` js
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var test = require('tape');
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var path = require('path');
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test.createStream({ objectMode: true }).on('data', function (row) {
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console.log(JSON.stringify(row))
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});
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process.argv.slice(2).forEach(function (file) {
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require(path.resolve(file));
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});
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```
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The output for this runner is:
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```sh
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$ node object.js test/x.js test/y.js
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{"type":"test","name":"(anonymous)","id":0}
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{"id":0,"ok":false,"name":"should be strictly equal","operator":"equal","actual":"beep","expected":"boop","error":{},"test":0,"type":"assert"}
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{"type":"end","test":0}
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{"type":"test","name":"(anonymous)","id":1}
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{"id":0,"ok":true,"name":"should be strictly equal","operator":"equal","actual":2,"expected":2,"test":1,"type":"assert"}
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{"id":1,"ok":true,"name":"(unnamed assert)","operator":"ok","actual":true,"expected":true,"test":1,"type":"assert"}
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{"type":"end","test":1}
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{"type":"test","name":"wheee","id":2}
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{"id":0,"ok":true,"name":"(unnamed assert)","operator":"ok","actual":true,"expected":true,"test":2,"type":"assert"}
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{"type":"end","test":2}
|
||
```
|
||
|
||
# install
|
||
|
||
With [npm](https://npmjs.org) do:
|
||
|
||
```sh
|
||
npm install tape --save-dev
|
||
```
|
||
|
||
# troubleshooting
|
||
|
||
Sometimes `t.end()` doesn’t preserve the expected output ordering.
|
||
|
||
For instance the following:
|
||
|
||
```js
|
||
var test = require('tape');
|
||
|
||
test('first', function (t) {
|
||
|
||
setTimeout(function () {
|
||
t.ok(1, 'first test');
|
||
t.end();
|
||
}, 200);
|
||
|
||
t.test('second', function (t) {
|
||
t.ok(1, 'second test');
|
||
t.end();
|
||
});
|
||
});
|
||
|
||
test('third', function (t) {
|
||
setTimeout(function () {
|
||
t.ok(1, 'third test');
|
||
t.end();
|
||
}, 100);
|
||
});
|
||
```
|
||
|
||
will output:
|
||
|
||
```
|
||
ok 1 second test
|
||
ok 2 third test
|
||
ok 3 first test
|
||
```
|
||
|
||
because `second` and `third` assume `first` has ended before it actually does.
|
||
|
||
Use `t.plan()` instead to let other tests know they should wait:
|
||
|
||
```diff
|
||
var test = require('tape');
|
||
|
||
test('first', function (t) {
|
||
|
||
+ t.plan(2);
|
||
|
||
setTimeout(function () {
|
||
t.ok(1, 'first test');
|
||
- t.end();
|
||
}, 200);
|
||
|
||
t.test('second', function (t) {
|
||
t.ok(1, 'second test');
|
||
t.end();
|
||
});
|
||
});
|
||
|
||
test('third', function (t) {
|
||
setTimeout(function () {
|
||
t.ok(1, 'third test');
|
||
t.end();
|
||
}, 100);
|
||
});
|
||
```
|
||
|
||
# license
|
||
|
||
MIT
|