# std/unittest

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Author: | Zahary Karadjov

This module implements boilerplate to make unit testing easy.

The test status and name is printed after any output or traceback.

Tests can be nested, however failure of a nested test will not mark the parent test as failed. Setup and teardown are inherited. Setup can be overridden locally.

Compiled test files as well as `nim c -r <testfile.nim>` exit with 0 for success (no failed tests) or 1 for failure.

# Testament

Instead of `unittest`, please consider using the Testament tool which offers process isolation for your tests.

Alternatively using `when isMainModule: doAssert conditionHere` is usually a much simpler solution for testing purposes.

# Running a single test

Specify the test name as a command line argument.

    nim c -r test "my test name" "another test"

Multiple arguments can be used.

# Running a single test suite

Specify the suite name delimited by `"::"`.

    nim c -r test "my test name::"

# Selecting tests by pattern

A single `"*"` can be used for globbing.

Delimit the end of a suite name with `"::"`.

Tests matching any of the arguments are executed.

    nim c -r test fast_suite::mytest1 fast_suite::mytest2
    nim c -r test "fast_suite::mytest*"
    nim c -r test "auth*::" "crypto::hashing*"
    # Run suites starting with 'bug #' and standalone tests starting with '#'
    nim c -r test 'bug #*::' '::#*'

# Examples

    suite "description for this stuff":
      echo "suite setup: run once before the tests"

      setup:
        echo "run before each test"

      teardown:
        echo "run after each test"

      test "essential truths":
        # give up and stop if this fails
        require(true)

      test "slightly less obvious stuff":
        # print a nasty message and move on, skipping
        # the remainder of this block
        check(1 != 1)
        check("asd"[2] == 'd')

      test "out of bounds error is thrown on bad access":
        let v = @[1, 2, 3]  # you can do initialization here
        expect(IndexDefect):
          discard v[4]

      echo "suite teardown: run once after the tests"

# Limitations/Bugs

Since `check` will rewrite some expressions for supporting checkpoints (namely assigns expressions to variables), some type conversions are not supported. For example `check 4.0 == 2 + 2` won't work. But `doAssert 4.0 == 2 + 2` works. Make sure both sides of the operator (such as `==`, `>=` and so on) have the same type.

# Imports

since, exitprocs, assertions, macros, strutils, streams, times, sets, sequtils, terminal

# Types

    ConsoleOutputFormatter = ref object of OutputFormatter
      ## Have test results printed in color.
      ## Default is `auto` depending on `isatty(stdout)`, or override it with
      ## `-d:nimUnittestColor:auto|on|off`.
      ##
      ## Deprecated: Setting the environment variable `NIMTEST_COLOR` to `always`
      ## or `never` changes the default for the non-js target to true or false respectively.
      ## Deprecated: the environment variable `NIMTEST_NO_COLOR`, when set, changes the
      ## default to true, if `NIMTEST_COLOR` is undefined.
      ## Set the verbosity of test results.
      ## Default is `PRINT_ALL`, or override with:
      ## `-d:nimUnittestOutputLevel:PRINT_ALL|PRINT_FAILURES|PRINT_NONE`.
      ##
      ## Deprecated: the `NIMTEST_OUTPUT_LVL` environment variable is set for the non-js target.

  Source Edit

    JUnitOutputFormatter = ref object of OutputFormatter

  Source Edit

    OutputFormatter = ref object of RootObj

  Source Edit

    OutputLevel = enum
      PRINT_ALL,                ## Print as much as possible.
      PRINT_FAILURES,           ## Print only the failed tests.
      PRINT_NONE                 ## Print nothing.

  The output verbosity of the tests. Source Edit

    TestResult = object
      suiteName*: string ## Name of the test suite that contains this test case.
                         ## Can be ``nil`` if the test case is not in a suite.
      testName*: string          ## Name of the test case
      status*: TestStatus

  Source Edit

    TestStatus = enum
      OK, FAILED, SKIPPED

  The status of a test when it is done. Source Edit

# Vars

    abortOnError {.threadvar.}: bool

  Set to true in order to quit immediately on fail. Default is false, or override with `-d:nimUnittestAbortOnError:on|off`.

  Deprecated: can also override depending on whether `NIMTEST_ABORT_ON_ERROR` environment variable is set.

  Source Edit

# Procs

    proc addOutputFormatter(formatter: OutputFormatter) {....raises: [], tags: [],
        forbids: [].}

  Source Edit

    proc checkpoint(msg: string) {....raises: [], tags: [], forbids: [].}

  Set a checkpoint identified by `msg`. Upon test failure all checkpoints encountered so far are printed out. Example:

      checkpoint("Checkpoint A")
      check((42, "the Answer to life and everything") == (1, "a"))
      checkpoint("Checkpoint B")

  outputs "Checkpoint A" once it fails.

  Source Edit

    proc close(formatter: JUnitOutputFormatter) {....raises: [IOError, OSError],
        tags: [WriteIOEffect], forbids: [].}

  Completes the report and closes the underlying stream. Source Edit

    proc defaultConsoleFormatter(): ConsoleOutputFormatter {....raises: [ValueError],
        tags: [], forbids: [].}

  Source Edit

    proc delOutputFormatter(formatter: OutputFormatter) {....raises: [], tags: [],
        forbids: [].}

  Source Edit

    proc disableParamFiltering() {....raises: [], tags: [], forbids: [].}

  disables filtering tests with the command line params Source Edit

    proc newConsoleOutputFormatter(outputLevel: OutputLevel = outputLevelDefault;
                                   colorOutput = true): ConsoleOutputFormatter {.
        ...raises: [], tags: [], forbids: [].}

  Source Edit

    proc newJUnitOutputFormatter(stream: Stream): JUnitOutputFormatter {.
        ...raises: [IOError, OSError], tags: [WriteIOEffect], forbids: [].}

  Creates a formatter that writes report to the specified stream in JUnit format. The `stream` is NOT closed automatically when the test are finished, because the formatter has no way to know when all tests are finished. You should invoke formatter.close() to finalize the report. Source Edit

    proc resetOutputFormatters() {....raises: [], tags: [], forbids: [].}

  Source Edit

# Methods

    method failureOccurred(formatter: ConsoleOutputFormatter;
                           checkpoints: seq[string]; stackTrace: string) {.
        ...raises: [], tags: [], forbids: [].}

  Source Edit

    method failureOccurred(formatter: JUnitOutputFormatter;
                           checkpoints: seq[string]; stackTrace: string) {.
        ...raises: [], tags: [], forbids: [].}

  `stackTrace` is provided only if the failure occurred due to an exception. `checkpoints` is never `nil`. Source Edit

    method failureOccurred(formatter: OutputFormatter; checkpoints: seq[string];
                           stackTrace: string) {.base, ...gcsafe, raises: [], tags: [],
        forbids: [].}

  `stackTrace` is provided only if the failure occurred due to an exception. `checkpoints` is never `nil`. Source Edit

    method suiteEnded(formatter: ConsoleOutputFormatter) {....raises: [], tags: [],
        forbids: [].}

  Source Edit

    method suiteEnded(formatter: JUnitOutputFormatter) {....raises: [IOError, OSError],
        tags: [WriteIOEffect], forbids: [].}

  Source Edit

    method suiteEnded(formatter: OutputFormatter) {.base, ...gcsafe, raises: [],
        tags: [], forbids: [].}

  Source Edit

    method suiteStarted(formatter: ConsoleOutputFormatter; suiteName: string) {.
        ...raises: [IOError, ValueError], tags: [WriteIOEffect], forbids: [].}

  Source Edit

    method suiteStarted(formatter: JUnitOutputFormatter; suiteName: string) {.
        ...raises: [IOError, OSError, ValueError], tags: [WriteIOEffect], forbids: [].}

  Source Edit

    method suiteStarted(formatter: OutputFormatter; suiteName: string) {.base,
        ...gcsafe, raises: [], tags: [], forbids: [].}

  Source Edit

    method testEnded(formatter: ConsoleOutputFormatter; testResult: TestResult) {.
        ...raises: [IOError, ValueError], tags: [WriteIOEffect], forbids: [].}

  Source Edit

    method testEnded(formatter: JUnitOutputFormatter; testResult: TestResult) {.
        ...raises: [IOError, OSError, ValueError], tags: [TimeEffect, WriteIOEffect],
        forbids: [].}

  Source Edit

    method testEnded(formatter: OutputFormatter; testResult: TestResult) {.base,
        ...gcsafe, raises: [], tags: [], forbids: [].}

  Source Edit

    method testStarted(formatter: ConsoleOutputFormatter; testName: string) {.
        ...raises: [], tags: [], forbids: [].}

  Source Edit

    method testStarted(formatter: JUnitOutputFormatter; testName: string) {.
        ...raises: [], tags: [TimeEffect], forbids: [].}

  Source Edit

    method testStarted(formatter: OutputFormatter; testName: string) {.base, ...gcsafe,
        raises: [], tags: [], forbids: [].}

  Source Edit

# Macros

    macro check(conditions: untyped): untyped

  Verify if a statement or a list of statements is true. A helpful error message and set checkpoints are printed out on failure (if `outputLevel` is not `PRINT_NONE`).

  Example:

      import std/strutils

      check("AKB48".toLowerAscii() == "akb48")

      let teams = {'A', 'K', 'B', '4', '8'}

      check:
        "AKB48".toLowerAscii() == "akb48"
        'C' notin teams

  Source Edit

    macro expect(exceptions: varargs[typed]; body: untyped): untyped

  Test if `body` raises an exception found in the passed `exceptions`. The test passes if the raised exception is part of the acceptable exceptions. Otherwise, it fails.

  Example:

      import std/[math, random, strutils]
      proc defectiveRobot() =
        randomize()
        case rand(1..4)
        of 1: raise newException(OSError, "CANNOT COMPUTE!")
        of 2: discard parseInt("Hello World!")
        of 3: raise newException(IOError, "I can't do that Dave.")
        else: assert 2 + 2 == 5

      expect IOError, OSError, ValueError, AssertionDefect:
        defectiveRobot()

  Source Edit

# Templates

    template fail()

  Print out the checkpoints encountered so far and quit if `abortOnError` is true. Otherwise, erase the checkpoints and indicate the test has failed (change exit code and test status). This template is useful for debugging, but is otherwise mostly used internally. Example:

      checkpoint("Checkpoint A")
      complicatedProcInThread()
      fail()

  outputs "Checkpoint A" before quitting.

  Source Edit

    template require(conditions: untyped)

  Same as `check` except any failed test causes the program to quit immediately. Any teardown statements are not executed and the failed test output is not generated. Source Edit

    template skip()

  Mark the test as skipped. Should be used directly in case when it is not possible to perform test for reasons depending on outer environment, or certain application logic conditions or configurations. The test code is still executed.

      if not isGLContextCreated():
        skip()

  Source Edit

    template suite(name, body) {.dirty.}

  Declare a test suite identified by `name` with optional `setup` and/or `teardown` section.

  A test suite is a series of one or more related tests sharing a common fixture (`setup`, `teardown`). The fixture is executed for EACH test.

      suite "test suite for addition":
        setup:
          let result = 4

        test "2 + 2 = 4":
          check(2+2 == result)

        test "(2 + -2) != 4":
          check(2 + -2 != result)

        # No teardown needed

  The suite will run the individual test cases in the order in which they were listed. With default global settings the above code prints:

      [Suite] test suite for addition
        [OK] 2 + 2 = 4
        [OK] (2 + -2) != 4

  Source Edit

    template test(name, body) {.dirty.}

  Define a single test case identified by `name`.

      test "roses are red":
        let roses = "red"
        check(roses == "red")

  The above code outputs:

      [OK] roses are red

  Source Edit