How to run test cases in a specified file?

My package test cases are scattered across multiple files, if I run go test <package_name> it runs all test cases in the package.

It is unnecessary to run all of them though. Is there a way to specify a file for go test to run, so that it only runs test cases defined in the file?

Solution 1:

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 -v 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.

Solution 2:

@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.

Solution 3:

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.

Solution 4:

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

Prevents caching of test results.

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

Solution 5:

alias testcases="sed -n 's/func.*\(Test.*\)(.*/\1/p' | xargs | sed 's/ /|/g'"

go test -v -run $(cat coordinator_test.go | testcases)