cmd/gogio: extract endtoend driver base into a type

This type contains all the common bits, such as *testing.T, as well as
the channel and method used to wait for blocking until a frame is ready.

It also allows us to initialise this base separately from Start, which
keeps the exported method simpler to understand.

The base type is embedded into the specific driver types, so that the
code remains simple. While at it, start embedding *testing.T too, so
that we can write d.Fatalf instead of d.t.Fatalf. The drivers will only
have a small number of exported methods as per the interface, so it's
easy to keep those from colliding with the method set on T.

Signed-off-by: Daniel Martí <mvdan@mvdan.cc>

cmd/gogio/android_test.go

@@ -15,14 +15,11 @@ import (
 	"path/filepath"
 	"regexp"
 	"strings"
-	"testing"
 	"time"
 )
 
 type AndroidTestDriver struct {
-	t *testing.T
-
-	frameNotifs chan bool
+	driverBase
 
 	sdkDir  string
 	adbPath string
@@ -30,13 +27,10 @@ type AndroidTestDriver struct {
 
 var rxAdbDevice = regexp.MustCompile(`(.*)\s+device$`)
 
-func (d *AndroidTestDriver) Start(t_ *testing.T, path string, width, height int) {
-	d.frameNotifs = make(chan bool, 1)
-	d.t = t_
-
+func (d *AndroidTestDriver) Start(path string, width, height int) {
 	d.sdkDir = os.Getenv("ANDROID_HOME")
 	if d.sdkDir == "" {
-		d.t.Skipf("Android SDK is required; set $ANDROID_HOME")
+		d.Skipf("Android SDK is required; set $ANDROID_HOME")
 	}
 	d.adbPath = filepath.Join(d.sdkDir, "platform-tools", "adb")
 
@@ -44,10 +38,10 @@ func (d *AndroidTestDriver) Start(t_ *testing.T, path string, width, height int)
 	devices := rxAdbDevice.FindAllSubmatch(devOut, -1)
 	switch len(devices) {
 	case 0:
-		d.t.Skipf("no Android devices attached via adb; skipping")
+		d.Skipf("no Android devices attached via adb; skipping")
 	case 1:
 	default:
-		d.t.Skipf("multiple Android devices attached via adb; skipping")
+		d.Skipf("multiple Android devices attached via adb; skipping")
 	}
 
 	// If the device is attached but asleep, it's probably just charging.
@@ -57,29 +51,29 @@ func (d *AndroidTestDriver) Start(t_ *testing.T, path string, width, height int)
 		d.adb("shell", "dumpsys", "power"),
 		[]byte(" mWakefulness=Awake"),
 	) {
-		d.t.Skipf("Android device isn't awake; skipping")
+		d.Skipf("Android device isn't awake; skipping")
 	}
 
 	// First, build the app.
 	dir, err := ioutil.TempDir("", "gio-endtoend-android")
 	if err != nil {
-		d.t.Fatal(err)
+		d.Fatal(err)
 	}
-	d.t.Cleanup(func() { os.RemoveAll(dir) })
+	d.Cleanup(func() { os.RemoveAll(dir) })
 	apk := filepath.Join(dir, "e2e.apk")
 
 	// TODO(mvdan): This is inefficient, as we link the gogio tool every time.
 	// Consider options in the future. On the plus side, this is simple.
 	cmd := exec.Command("go", "run", ".", "-target=android", "-appid="+appid, "-o="+apk, path)
 	if out, err := cmd.CombinedOutput(); err != nil {
-		d.t.Fatalf("could not build app: %s:\n%s", err, out)
+		d.Fatalf("could not build app: %s:\n%s", err, out)
 	}
 
 	// Make sure the app isn't installed already, and try to uninstall it
 	// when we finish. Previous failed test runs might have left the app.
 	d.tryUninstall()
 	d.adb("install", apk)
-	d.t.Cleanup(d.tryUninstall)
+	d.Cleanup(d.tryUninstall)
 
 	// Force our e2e app to be fullscreen, so that the android system bar at
 	// the top doesn't mess with our screenshots.
@@ -101,13 +95,13 @@ func (d *AndroidTestDriver) Start(t_ *testing.T, path string, width, height int)
 		)
 		logcat, err := cmd.StdoutPipe()
 		if err != nil {
-			d.t.Fatal(err)
+			d.Fatal(err)
 		}
 		cmd.Stderr = os.Stderr
 		if err := cmd.Start(); err != nil {
-			d.t.Fatal(err)
+			d.Fatal(err)
 		}
-		d.t.Cleanup(cancel)
+		d.Cleanup(cancel)
 		go func() {
 			scanner := bufio.NewScanner(logcat)
 			for scanner.Scan() {
@@ -130,14 +124,14 @@ func (d *AndroidTestDriver) Start(t_ *testing.T, path string, width, height int)
 	time.Sleep(500 * time.Millisecond)
 
 	// Wait for the gio app to render.
-	waitForFrame(d.t, d.frameNotifs)
+	d.waitForFrame()
 }
 
 func (d *AndroidTestDriver) Screenshot() image.Image {
 	out := d.adb("shell", "screencap", "-p")
 	img, err := png.Decode(bytes.NewReader(out))
 	if err != nil {
-		d.t.Fatal(err)
+		d.Fatal(err)
 	}
 	return img
 }
@@ -150,7 +144,7 @@ func (d *AndroidTestDriver) tryUninstall() {
 			// The package is not installed. Don't log anything.
 			return
 		}
-		d.t.Logf("could not uninstall: %v\n%s", err, out)
+		d.Logf("could not uninstall: %v\n%s", err, out)
 	}
 }
 
@@ -162,8 +156,8 @@ func (d *AndroidTestDriver) adb(args ...interface{}) []byte {
 	cmd := exec.Command(d.adbPath, strs...)
 	out, err := cmd.CombinedOutput()
 	if err != nil {
-		d.t.Errorf("%s", out)
-		d.t.Fatal(err)
+		d.Errorf("%s", out)
+		d.Fatal(err)
 	}
 	return out
 }
@@ -172,5 +166,5 @@ func (d *AndroidTestDriver) Click(x, y int) {
 	d.adb("shell", "input", "tap", x, y)
 
 	// Wait for the gio app to render after this click.
-	waitForFrame(d.t, d.frameNotifs)
+	d.waitForFrame()
 }