How to run test cases in a specified file?

When running a single test I usually do:

go test -run TestSomethingReallyCool ./folder1/folder2/ -v -count 1

-count 1 also ensures that the test is ran every time instead of being cached. Useful when you are testing against race conditions and have a test that fails only sometimes. In Go versions not using modules the same could be achieved by setting GOCACHE=off but this interacts poorly with Go modules.

@zzzz's answer is mostly complete, but just to save others from having to dig through the referenced documentation you can run a single test in a package as follows:

go test packageName -run TestName

Note that you want to pass in the name of the test, not the file name where the test exists.

The -run flag actually accepts a regex so you could limit the test run to a class of tests. From the docs:

-run regexp
    Run only those tests and examples matching the regular
    expression.

go test -v ./<package_name> -run Test

Prevents caching of test results.

go test -count=1 ./<package_name> -run Test

There are two ways. The easy one is to use the -run flag and provide a pattern matching names of the tests you want to run.

Example:

$ go test packageName -run NameOfTest

See the docs for more info.

Note that the -run flag may also run other tests if they contain the string NameOfTest, as the -run flag matches a regexp.

So to ensure that only a test named exactly 'NameOfTest' is run, one has to use the regexp ^NameOfTest$:

$ go test -run "^NameOfTest$" 

The other way is to name the specific file, containing the tests you want to run:

$ go test foo_test.go

But there's a catch. This works well if:

• foo.go is in package foo.
• foo_test.go is in package foo_test and imports 'foo'.

If foo_test.go and foo.go are the same package (a common case) then you must name all other files required to build foo_test. In this example it would be:

$ go test foo_test.go foo.go

I'd recommend to use the -run pattern. Or, where/when possible, always run all package tests.