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10.0.1 • Public • Published


parse the test anything protocol

build status

browser support

coverage status


var Parser = require('tap-parser');
var p = new Parser(function (results) {

given some TAP-formatted input:

$ node test.js
TAP version 13
# beep
ok 1 should be equal
ok 2 should be equivalent
# boop
ok 3 should be equal
ok 4 (unnamed assert)

# tests 4
# pass  4

# ok

parse the output:

$ node test.js | node parse.js
{ ok: true, count: 4, pass: 4, plan: { start: 1, end: 4 } }


This package also has a tap-parser command.

  tap-parser <options>

Parses TAP data from stdin, and outputs the parsed result
in the format specified by the options.  Default output is
uses node's `util.format()` method.


  -j [<indent>] | --json[=indent]
    Output event data as JSON with the specified indentation (default=2)

  -t | --tap
    Output data as reconstituted TAP based on parsed results

  -l | --lines
    Output each parsed line as it is recognized by the parser

  -b | --bail
    Emit a `Bail out!` at the first failed test point encountered

  -w | --ignore-all-whitespace
    Skip over blank lines outside of YAML blocks

  -o | --omit-version
    Ignore the `TAP version 13` line at the start of tests


var Parser = require('tap-parser')

var p = new Parser(options, cb)

Return a writable stream p that emits parse events.

If cb is given it will listen for the 'complete' event.

If options is given, it may contain the following flags:

  • preserveWhitespace boolean which is false by default and will cause the parser to emit line events even for lines containing only whitespace. (Whitespace lines in yaml blocks are always emitted, because whitespace is semantically relevant for yaml.)

  • strict boolean which is false by default and causes the parser to treat non-TAP input as a failure. Strictness is heritable to child subtests. You can also turn strictness on or off by using the pragma +strict line in the TAP data to turn strictness on, or pragma -strict to turn strictness off.

  • bail boolean which is false by default and will cause the parser to bail out (including emitting a synthetic Bail out! line) whenever a failed test point is encountered.

  • omitVersion boolean which is false by default and will cause the parser to ignore TAP version 13 lines. Version lines in subtests cause problems with some parsers, so they are always ignored.

  • passes boolean which is false by default and will add "passes" property for that contains the result of all passed tests

The parent, level and buffered options are reserved for internal use.


p.on('complete', function (results) {})

The results object contains a summary of the number of tests skipped, failed, passed, etc., as well as a boolean ok member which is true if and only if the planned test were all found, and either "ok" or marked as "TODO".

p.on('line', function (line) {})

As each line of input is parsed, a line event is emitted.

"Synthetic" line events will be emitted to support the bail behavior, and to inject 1..0 plan lines in subtests that have no test points. They can be used as a sort of "passthrough stream" to sanitize and filter a TAP stream, with the caveat that, while line events will be semantically equivalent to the TAP input, they will not be a perfect replica of the input.

p.on('assert', function (assert) {})

Every /^(not )?ok\b/ line will emit an 'assert' event.

Every assert object has these keys:

  • assert.ok - true if the assertion succeeded, false if failed
  • - the assertion number
  • - optional short description of the assertion

and may also have

  • assert.todo - optional description of why the assertion failure is not a problem. (Boolean true if no explaination provided)
  • assert.skip - optional description of why this assertion was skipped (boolean true if no explanation provided)
  • assert.diag - a diagnostic object with additional information about the test point.

p.on('comment', function (comment) {})

Every /^# (.+)/ line will emit the string contents of comment.

p.on('plan', function (plan) {})

Every /^\d+\.\.\d+/ line emits a 'plan' event for the test numbers plan.start through plan.end, inclusive.

If the test is completely skipped the result will look like

{ ok: true,
  count: 0,
  pass: 0,
   { start: 1,
     end: 0,
     skipAll: true,
     skipReason: 'This code has no seat belt' } }

p.on('version', function (version) {})

A /^TAP version (\d+)/ line emits a 'version' event with a version number or string.

p.on('bailout', function (reason) {})

A bail out! line will cause the parser to completely stop doing anything. Child parser bailouts will bail out their parents as well.

p.on('child', function (childParser) {})

If a child test set is embedded in the stream like this:

TAP Version 13
# nesting
    ok 1 - true is ok
    ok 2 - doag is also okay
ok 1 - nesting
ok 2 - second

then the child stream will be parsed and events will be raised on the childParser object.

Since TAP streams with child tests must follow child test sets with a pass or fail assert based on the child test's results, failing to handle child tests should always result in the same end result. However, additional information from those child tests will obviously be lost.

See Subtests below for more information on which sorts of subtest formats are supported by this parser.

p.on('result', function (assert) {})

This is the same as the assert event, except that it only emits on the root parser, whenever it or any child parser has an assert event that is not merely closing a child test block.

p.on('pass', function (assert) {})

p.on('fail', function (assert) {})

p.on('skip', function (assert) {})

p.on('todo', function (assert) {})

Emitted on the root parser object, whenever it or any child parser has an assert event that is not merely closing a child test block, if the result is of the appropriate type.

p.on('extra', function (extra) {})

All other lines will trigger an 'extra' event with the line text.


With npm do:

npm install tap-parser

You can use browserify to require('tap-parser') in the browser.




5 flavors of Subtests are suppored by this parser.

  1. Unadorned. Indented TAP data with no comment, followed by a test point at the parent level.

        ok 1
    ok 1 - child test
  2. Indented comment. An indented # Subtest: <name> comment, followed by indented TAP data, and then a not-indented test point with a matching name. The summary test point may have yaml diagnostics.

        # Subtest: child test
        ok 1
    ok 1 - child test
  3. Unindented comment. A not-indented # Subtest: <name> comment, followed by indented TAP content, followed by a test point with a matching name. The summary test point may have yaml diagnostics.

    # Subtest: child test
        ok 1
    ok 1 - child test
  4. Buffered, without diagnostics. A test point line ending in {, followed by indented TAP content, ended with a } to close the block. todo/skip directives may come either before or after the { character. Yaml diagnostics are not allowed.

    ok 1 - child test {
        ok 1
  5. Buffered, with diagnostics. A test point line with yaml diagnostics, followed by { alone on a line, indented TAP data, and then a }.

    ok 1 - child test
      some: diagnostic
      data: true
        ok 1

In all cases, the parsed behavior is identical:

  1. The parent emits a child event with the childParser as an argument.
  2. The childParser emits a comment with # Subtest: <name> (or (anonymous) for Unadorned subtests.)
  3. When the test is over, the closing test point is emitted on parent test.

That is, buffered and nonindented/indented comment subtests are parsed as if they are identical input, since their semantics are the same. This simplifies implementation of test harness and reporter modules.

Since unadorned subtests have no introduction, a child event is not emitted until the first "relevant tap" line is encountered. This can cause confusion if the test output contains a spurious " 1..2" line or something, but such cases are rare.

Similarly, this means that a test point ending in { needs to wait to emit either the 'assert' or 'child' events until an indented line is encountered. Any test point with yaml diagnostics needs to wait to see if it will be followed by a { indicating a subtest.


npm i tap-parser

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