flags
#####

control the execution of any test
=================================

-bench regexp::

    Run only those benchmarks matching a regular expression.
    By default, no benchmarks are run.
    To run all benchmarks, use '-bench .' or '-bench=.'.
    The regular expression is split by unbracketed slash (/)
    characters into a sequence of regular expressions, and each
    part of a benchmark's identifier must match the corresponding
    element in the sequence, if any. Possible parents of matches
    are run with b.N=1 to identify sub-benchmarks. For example,
    given -bench=X/Y, top-level benchmarks matching X are run
    with b.N=1 to find any sub-benchmarks matching Y, which are
    then run in full.

-benchtime t::

    Run enough iterations of each benchmark to take t, specified
    as a time.Duration (for example, -benchtime 1h30s).
    The default is 1 second (1s).
    The special syntax Nx means to run the benchmark N times
    (for example, -benchtime 100x).

-count n::

    Run each test and benchmark n times (default 1).
    If -cpu is set, run n times for each GOMAXPROCS value.
    Examples are always run once.

-cover::

    Enable coverage analysis.
    Note that because coverage works by annotating the source
    code before compilation, compilation and test failures with
    coverage enabled may report line numbers that don't correspond
    to the original sources.

-covermode set,count,atomic::

    Set the mode for coverage analysis for the package[s]
    being tested. The default is "set" unless -race is enabled,
    in which case it is "atomic".
    The values:
      set: bool: does this statement run?
      count: int: how many times does this statement run?
      atomic: int: count, but correct in multithreaded tests;
            significantly more expensive.
    Sets -cover.

-coverpkg pattern1,pattern2,pattern3::

    Apply coverage analysis in each test to packages matching the patterns.
    The default is for each test to analyze only the package being tested.
    See 'go help packages' for a description of package patterns.
    Sets -cover.

-cpu 1,2,4::

    Specify a list of GOMAXPROCS values for which the tests or
    benchmarks should be executed. The default is the current value
    of GOMAXPROCS.

-failfast::

    Do not start new tests after the first test failure.

-list regexp::

    List tests, benchmarks, or examples matching the regular expression.
    No tests, benchmarks or examples will be run. This will only
    list top-level tests. No subtest or subbenchmarks will be shown.

-parallel n::

    Allow parallel execution of test functions that call t.Parallel.
    The value of this flag is the maximum number of tests to run
    simultaneously; by default, it is set to the value of GOMAXPROCS.
    Note that -parallel only applies within a single test binary.
    The 'go test' command may run tests for different packages
    in parallel as well, according to the setting of the -p flag
    (see 'go help build').

-run regexp::

    Run only those tests and examples matching the regular expression.
    For tests, the regular expression is split by unbracketed slash (/)
    characters into a sequence of regular expressions, and each part
    of a test's identifier must match the corresponding element in
    the sequence, if any. Note that possible parents of matches are
    run too, so that -run=X/Y matches and runs and reports the result
    of all tests matching X, even those without sub-tests matching Y,
    because it must run them to look for those sub-tests.

-short::

    Tell long-running tests to shorten their run time.
    It is off by default but set during all.bash so that installing
    the Go tree can run a sanity check but not spend time running
    exhaustive tests.

-timeout d::

    If a test binary runs longer than duration d, panic.
    If d is 0, the timeout is disabled.
    The default is 10 minutes (10m).

-v::

    Verbose output: log all tests as they are run. Also print all
    text from Log and Logf calls even if the test succeeds.

-vet list::

    Configure the invocation of "go vet" during "go test"
    to use the comma-separated list of vet checks.
    If list is empty, "go test" runs "go vet" with a curated list of
    checks believed to be always worth addressing.
    If list is "off", "go test" does not run "go vet" at all.

profile the tests during execution
==================================

-benchmem::

    Print memory allocation statistics for benchmarks.

-blockprofile block.out::

    Write a goroutine blocking profile to the specified file
    when all tests are complete.
    Writes test binary as -c would.

-blockprofilerate n::

    Control the detail provided in goroutine blocking profiles by
    calling runtime.SetBlockProfileRate with n.
    See 'go doc runtime.SetBlockProfileRate'.
    The profiler aims to sample, on average, one blocking event every
    n nanoseconds the program spends blocked. By default,
    if -test.blockprofile is set without this flag, all blocking events
    are recorded, equivalent to -test.blockprofilerate=1.

-coverprofile cover.out::

    Write a coverage profile to the file after all tests have passed.
    Sets -cover.

-cpuprofile cpu.out::

    Write a CPU profile to the specified file before exiting.
    Writes test binary as -c would.

-memprofile mem.out::

    Write an allocation profile to the file after all tests have passed.
    Writes test binary as -c would.

-memprofilerate n::

    Enable more precise (and expensive) memory allocation profiles by
    setting runtime.MemProfileRate. See 'go doc runtime.MemProfileRate'.
    To profile all memory allocations, use -test.memprofilerate=1.

-mutexprofile mutex.out::

    Write a mutex contention profile to the specified file
    when all tests are complete.
    Writes test binary as -c would.

-mutexprofilefraction n::

    Sample 1 in n stack traces of goroutines holding a
    contended mutex.

-outputdir directory::

    Place output files from profiling in the specified directory,
    by default the directory in which "go test" is running.

-trace trace.out::

    Write an execution trace to the specified file before exiting.


实例
====

::

    $ go test -v -myflag testdata -cpuprofile=prof.out -x
    // compile the test binary and then run it as
    // pkg.test -test.v -myflag testdata -test.cpuprofile=prof.out


    $ go test -v -args -x -v
    // compile the test binary and then run it as
    pkg.test -test.v -x -v


    $ go test -args math
    // compile the test binary and then run it as
    // pkg.test math