testutil: tests that behave the same everywhere¶

import "github.com/grokify/oscompat/testutil"

Home directory¶

func TestConfig(t *testing.T) {
    home := testutil.SetTempHomeDir(t)
    // os.UserHomeDir() now returns home on every platform
}

It sets both HOME and USERPROFILE, because Windows reads the second, and removes the directory when the test ends.

Durations¶

The Windows clock advances in steps of about 15.6 ms, so a fast operation can measure as zero.

testutil.AssertDurationNonNegative(t, elapsed)
if testutil.DurationNonNegative(elapsed) { /* ... */ }

Assert that a duration is not negative, never that it is positive.

Capturing output¶

out, err := testutil.CaptureStdout(func() { fmt.Println("hi") })
stdout, stderr, err := testutil.CaptureOutput(func() { /* ... */ })

The pipe is read concurrently, which avoids the deadlock a large write causes on Windows when a test reads only after the function returns.

Fixtures and golden files¶

Git may check out text files with CRLF on Windows, so a fixture read from disk can differ from the same bytes generated in the test.

want := testutil.ReadFileLF(t, "testdata/input.json") // CRLF becomes LF

var update = flag.Bool("update", false, "rewrite the golden files")

testutil.AssertGolden(t, "testdata/out.json", got, *update)

AssertGolden compares got with the file ignoring CRLF versus LF, and writes the file instead when update is set. Produce got with LF endings. For a string or bytes already in memory, use fs.NormalizeLineEndings or fs.NormalizeLineEndingsBytes.