Test Helpers for Go

test-helpers.go

// testTempFile
// create a temp file using only a single line
// cleanly manages err handling
func testTempFile(t *testing.T) string {
  tf, err := ioutil.TempFile("", "test")
  if err != nil {
    t.Fatalf("err: %s", err)
  }
  tf.Close()
  
  return tf.Name()
}

// testChdir
// use defer to return to a previous state.
// this example shows changing a directory and changing it back later.
func testChdir(t *testing.T, dir string) func() {
  old, err := os.Getwd()
  if err != nil {
    t.Fatalf("err: %s", err)
  }
  
  if err := os.Chdir(dir); err != nil {
    t.Fatalf("err: %s", err)
  }
  
  return func() { os.Chdir(old) }
}

func TestThing(t *testing.T) {
  defer testChdir(t, "/other")()
  
  // ... test something
}