MM-19022: Convert config/watcher_test.go t.Fatal calls into require calls (#12524)

* Convert config/watcher_test.go t.Fatal calls into require calls

* Moved wasCalled to a public helper function

Now the testutils package has a new function WasCalled
that can be used by anywhere.

config/watcher_test.go

@@ -11,6 +11,8 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/require"
+
+	"github.com/mattermost/mattermost-server/utils/testutils"
 )
 
 func TestWatcherInvalidDirectory(t *testing.T) {
@@ -47,17 +49,9 @@ func TestWatcher(t *testing.T) {
 
 	// Write to a different file
 	ioutil.WriteFile(filepath.Join(tempDir, "unrelated"), []byte("data"), 0644)
-	select {
+	require.False(t, testutils.WasCalled(called, 1*time.Second), "callback should not have been called for unrelated file")
-	case <-called:
-		t.Fatal("callback should not have been called for unrelated file")
-	case <-time.After(1 * time.Second):
-	}
 
 	// Write to the watched file
 	ioutil.WriteFile(f.Name(), []byte("data"), 0644)
-	select {
+	require.True(t, testutils.WasCalled(called, 5*time.Second), "callback should have been called when file written")
-	case <-called:
-	case <-time.After(5 * time.Second):
-		t.Fatal("callback should have been called when file written")
-	}
 }

utils/testutils/testutils.go

@@ -8,6 +8,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"time"
 
 	"github.com/mattermost/mattermost-server/utils/fileutils"
 )
@@ -27,3 +28,15 @@ func ReadTestFile(name string) ([]byte, error) {
 		return data.Bytes(), nil
 	}
 }
+
+// WasCalled reports whether a given callback channel was called
+// within the specified time duration or not.
+func WasCalled(c chan bool, duration time.Duration) bool {
+	wasCalled := false
+	select {
+	case <-c:
+		wasCalled = true
+	case <-time.After(duration):
+	}
+	return wasCalled
+}