tasty- Modern and extensible testing framework
Safe HaskellNone



Console reporter ingredient



consoleTestReporter :: Ingredient Source #

A simple console UI

newtype Quiet Source #

Do not print test results (see README for details)


Quiet Bool 

newtype AnsiTricks Source #

By default, when the option --hide-successes is given and the output goes to an ANSI-capable terminal, we employ some ANSI terminal tricks to display the name of the currently running test and then erase it if it succeeds.

These tricks sometimes fail, however—in particular, when the test names happen to be longer than the width of the terminal window. See

When that happens, this option can be used to disable the tricks. In that case, the test name will be printed only once the test fails.





The following functions and datatypes are internals that are exposed to simplify the task of rolling your own custom console reporter UI.

Output colouring

data UseColor Source #

When to use color on the output

Since: 0.11.3



Only if stdout is an ANSI color supporting terminal

useColor :: UseColor -> Bool -> Bool Source #

useColor when isTerm decides if colors should be used, where isTerm indicates whether stdout is a terminal device.

Since: 0.11.3

Test failure statistics

data Statistics Source #

Track the number of tests that were run and failures of a TestTree or sub-tree.

Since: 0.11.3




  • statTotal :: !Int

    Number of active tests (e.g., that match the pattern specified on the commandline), inactive tests are not counted.

  • statFailures :: !Int

    Number of active tests that failed.

computeStatistics :: StatusMap -> IO Statistics Source #

computeStatistics computes a summary Statistics for a given state of the StatusMap. Useful in combination with printStatistics

printStatistics :: (?colors :: Bool) => Statistics -> Time -> IO () Source #

printStatistics reports test success/failure statistics and time it took to run. The Time results is intended to be filled in by the TestReporter callback. The colors ImplicitParam controls whether coloured output is used.

Since: 0.11.3

printStatisticsNoTime :: (?colors :: Bool) => Statistics -> IO () Source #

printStatisticsNoTime reports test success/failure statistics The colors ImplicitParam controls whether coloured output is used.

Since: 0.12

Outputting results

data TestOutput Source #

TestOutput is an intermediary between output formatting and output printing. It lets us have several different printing modes (normal; print failures only; quiet).

Since: 0.12


PrintTest String (IO ()) (Result -> IO ())

Name of a test, an action that prints the test name, and an action that renders the result of the action.

PrintHeading String (IO ()) TestOutput

Name of a test group, an action that prints the heading of a test group and the TestOutput for that test group.


Inactive test (e.g. not matching the current pattern)

Seq TestOutput TestOutput

Two sets of TestOuput on the same level

buildTestOutput :: (?colors :: Bool) => OptionSet -> TestTree -> TestOutput Source #

Build the TestOutput for a TestTree and OptionSet. The colors ImplicitParam controls whether the output is colored.

Since: 0.11.3

foldTestOutput Source #


:: Monoid b 
=> (String -> IO () -> IO Result -> (Result -> IO ()) -> b)

Eliminator for test cases. The IO () prints the testname. The IO Result blocks until the test is finished, returning it's Result. The Result -> IO () function prints the formatted output.

-> (String -> IO () -> b -> b)

Eliminator for test groups. The IO () prints the test group's name. The b is the result of folding the test group.

-> TestOutput

The TestOutput being rendered.

-> StatusMap

The StatusMap received by the TestReporter

-> b 

Fold function for the TestOutput tree into a Monoid.

Since: 0.12

withConsoleFormat :: (?colors :: Bool) => ConsoleFormatPrinter Source #

Run action with console configured for a specific output format

This function does not apply any output formats if colors are disabled at command line or console detection.

Can be used by providers that wish to provider specific result details printing, while re-using the tasty formats and coloring logic.

Since: 1.3.1