control the execution of any test¶
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.
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).
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.
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.
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.
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.
Specify a list of GOMAXPROCS values for which the tests or benchmarks should be executed. The default is the current value of GOMAXPROCS.
Do not start new tests after the first test failure.
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.
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 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.
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.
If a test binary runs longer than duration d, panic. If d is 0, the timeout is disabled. The default is 10 minutes (10m).
Verbose output: log all tests as they are run. Also print all text from Log and Logf calls even if the test succeeds.
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¶
Print memory allocation statistics for benchmarks.
Write a goroutine blocking profile to the specified file when all tests are complete. Writes test binary as -c would.
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.
Write a coverage profile to the file after all tests have passed. Sets -cover.
Write a CPU profile to the specified file before exiting. Writes test binary as -c would.
Write an allocation profile to the file after all tests have passed. Writes test binary as -c would.
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.
Write a mutex contention profile to the specified file when all tests are complete. Writes test binary as -c would.
Sample 1 in n stack traces of goroutines holding a contended mutex.
Place output files from profiling in the specified directory, by default the directory in which "go test" is running.
Write an execution trace to the specified file before exiting.
$ 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