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TIL: Skipping Tests in Go

jonasbn
Computer programmer, runner, LEGO builder, powernapper, yakshaver and father of 2 boys all squeezed in the few hours available.
・2 min read

The Go testing framework and toolchain has a nifty facility, where you can skip tests, if you do not want them to be a part of every run.

Let say we have a basic implementation

package shorttest

import (
    "fmt"
    "time"
)

func DoUnimportantStuff() uint8 {
    fmt.Println("Doing unimportant stuff")

    time.Sleep(10 * time.Second)

    return 1
}

func DoImportantStuff() uint8 {
    fmt.Println("Doing important stuff")

    return 1
}
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And we have a corresponding test suite:

package shorttest

import "testing"

func TestImportant(t *testing.T) {
    got := DoImportantStuff()
    if got != 1 {
        t.Errorf("Important stuff not correct, needed %d", got)
    }
}

func TestUnimportant(t *testing.T) {
    if testing.Short() {
        t.Skip("skipping test in short mode.")
    } else {
        got := DoUnimportantStuff()
        if got != 1 {
            t.Errorf("Unimportant stuff not correct, needed %d", got)
        }
    }
}
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When we are developing and want fast feedback, we do not want to wait for the long running and unimportant test to finish, but we are VERY interested in getting feedback on our important function as fast as possible.

When we just test we will observe waiting time

$ go test
Doing important stuff
Doing unimportant stuff
PASS
ok      shorttest   10.364s
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We can then skip the execution of the unimportant tests by executing our test suite with the --short flag.

❯ go test --short
Doing important stuff
PASS
ok      shorttest   0.116s
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We just have to remember to add the handling of --short via testing.Short() in the non-critical and long running tests.

Resources and References

  1. Go Command: Testing Flags
  2. Go Package testing: Skipping

Lifted from my TIL collection

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