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?

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.

@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.

When running a single test I usually do:

<!-- language: bash -->

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.

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

Prevents caching of test results.

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

Visual Studio Code shows a link at the top of a Go test file which lets you run all the tests in just that file.

In the "Output" window, you can see that it automatically generates a regex which contains all of the test names in the current file:

Running tool: C:\Go\bin\go.exe test -timeout 30s -run ^(TestFoo|TestBar|TestBaz)$ rootpackage\mypackage

Note: the very first time you open a Go file in VS Code it automatically offers to install some Go extensions for you. I assume the above requires that you have previously accepted the offer to install.

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

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

go test -v -timeout 30s <path_to_package> -run ^(TestFuncRegEx)

• The TestFunc must be inside a go test file in that package
• We can provide a regular expression to match a set of test cases or just the exact test case function to run a single test case. For instance -run TestCaseFunc

I was facing some issue to run a single specific test from my package this is how I solved

go test -v -race ./parsers/xml2csv/stld/ -timeout 30s -run '^Test_stldItemParser_readNodes$'

If I run without single quote it wasn't working I use oh-my-zsh in Ubuntu-20.04

Here

-v             for verbosity
-race          to detect race condition
-timeout       for the timeout of the test

This are optional can be omitted but good to add.