tap Reporting Results

While TAP is intended to be both machine parseable and human intelligible, and the raw TAP content is often a good way to see exactly what is happening with a test, it tends to be quite a bit too noisy for regular ergonomic human consumption.

For this reason, tap comes with an ink-based reporter system, and additional reporters can be added as well.

You can specify the reporter to use with the --reporter config option. Custom reporters can be an Ink-based React component, a Stream class, or a CLI program.

Included Reporters#

The base reporter is the one that tap uses by default. It shows information about tests as they are running in parallel, and aims to be verbose enough to show you what's going on, without showing more information that is useful.

If the base reporter is too noisy for your liking, you can use the terse reporter, which is similar, but prints much less information.

Both reporters are designed to be as accessible as possible, featuring diff and syntax highlighting color choices that are amenable to any level of color sensitivity.

$ tap t.mts
 PASS  t.mts 2 OK 1.052s

                       
  🌈 TEST COMPLETE 🌈  
                       
Asserts:  2 pass  0 fail  2 of 2 complete
Suites:   1 pass  0 fail  1 of 1 complete

# { total: 2, pass: 2 }
# time=1091.538ms

The other included reporters are:

min - Even more terse than terse. Nothing at all is printed unless a failure occurs.
silent - Literally as terse as it is possible to be. No test results are printed anywhere.
dot - Similar to min, but prints a dot for each assertion, colored appropriately for its pass/fail/skip/todo status. (Or, if colors are disabled, just a regular dot.)
junit - JUnit style XML results.
json - Output the results of the test run as a single JSON object.
jsonstream - Line-delmited JSON, printing an array message for each suite and assertion.
markdown - Similar to jsonstream, but markdown instead of JSON.
tap - Just the raw TAP stream.

Those are just the built-in reports. You can write your own using the @tapjs/reporter library.

Reporting to a File#

Particularly for the JSON, XML, or Markdown reporters, it can be useful to pipe to a file.

To do this, you can set the --reporter-file option (shorthand: -f) to a path on disk. For example:

$ # write the xml to rspec.xml
$ tap -R junit --reporter-file rspec.xml

You can also use the replay command in this case to output a human-friendly report only on test failure:

$ # will create xml file, only print verbose report on failure
$ tap -R junit --reporter-file rspec.xml || tap replay

Ink-Based Reporters#

To use a custom reporter written in Ink, set the --reporter config option to the module which default-exports a React tag taking a TAP object as the tap attribute, and a LoadedConfig object as the config attribute.

Stream-Based Reporters#

Alternatively, you can set --reporter to a module that default-exports a Writable Stream class. (That is, a class with write and end methods on its prototype.)

In this case, the class will be instantiated with no arguments, and the root TAP test will be piped into it.

CLI-Based Reporters#

Lastly, you can provide a name of an executable program, which will receive the TAP content on its standard input.

In this case, the --reporter-arg config options may be used to set the arguments to the reporter program.

For example,

$ npm install --save-dev tap-mocha-reporter
$ tap -R tap-mocha-reporter -r nyan
 94  -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_,------,
 0   -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_|   /\_/\ 
 0   -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-^|__( ^ .^) 
     -_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-  ""  "" 

  94 passing (5s)