fix(sample-app): make it standalone, no repo_root assumptions (#8)

* fix(cli): fall back to node_modules for @uatu/spec resolution

Drop the hard failure when the uatu source tree is not reachable from
the spec file. Users integrating uatu in their own app have @uatu/spec
installed via npm; esbuild now resolves it from node_modules.

* build(gradle): drop :sample-app include from root settings

The sample now has its own Gradle project in examples/sample-app/android.

* build(sample-app): vendor gradle wrapper

Users running the sample build the APK via ./gradlew from inside the
sample-app's own android/ directory, no repo-root wrapper required.

* build(sample-app): make gradle project standalone

Drop the project(':sdk-android') dependency in favor of the Maven
Central coordinate io.github.priyanshujain:sdk-android. The sample now
owns its settings.gradle.kts and gradle.properties, so it builds
without any pieces of the uatu source tree.

* chore(sample-app): declare @uatu/spec npm dependency

Mirrors what a downstream user would put in their own package.json.
Uses file: for pre-release development; becomes a normal semver pin
once @uatu/spec ships to npm.

* docs(sample-app): rewrite justfile and add README

Justfile drops repo_root; all recipes run against the local gradle
wrapper and uatu from PATH. README is scoped to what a user needs to
run the sample against their own device.

* docs(manual): update sample install steps to standalone layout

./gradlew :sample-app:installDebug no longer exists; the sample owns
its own wrapper under android/.

* feat(sdk): log when Uatu.start succeeds

Silent SDK start makes the "SDK didn't connect" failure mode
impossible to debug. One INFO line at start time is enough.

* fix(sidecar): launch via am start -W instead of monkey

monkey -p <pkg> -c LAUNCHER 1 is unreliable on API 36+: it reports no
error but silently fails to start the activity, so the SDK never runs
and the CLI times out on the SDK-accept handshake.

Resolve the launcher activity via `cmd package resolve-activity
--brief` and launch it with `am start -W -n`. -W makes the call block
until the activity is up, which also makes the subsequent SDK
accept timing deterministic.

* feat(cli): auto-resolve Android device; boot AVD if none connected

--avd becomes optional. Resolution order:
 - use any already-connected adb device;
 - else if --avd names an existing AVD, boot it and wait for boot;
 - else if --avd is missing or names no AVD, error with a clear message.

Falls back to $ANDROID_HOME/emulator/emulator when the binary is not on
PATH, so a standard Android SDK install works without extra shell setup.

* docs(sample-app): AVD is optional; document both paths

just test runs against any connected device. If none, pass AVD=<name>
to have uatu boot the emulator for you.

* feat(cli): auto-discover Android SDK; auto-pick the lone AVD

adb and emulator are looked up via PATH, then $ANDROID_HOME,
$ANDROID_SDK_ROOT, ~/Library/Android/sdk, ~/Android/Sdk, and the
Homebrew cask path. The discovered platform-tools directory is
prepended to the sidecar's PATH so its adb subprocess calls work too.

When --avd isn't passed and no device is connected, the CLI picks the
sole local AVD and boots it. Multiple AVDs → error listing them.

* build(make): add `make install` that go-installs uatu onto PATH

Puts `uatu` into $GOBIN (or $GOPATH/bin) so the sample and any local
dev flow can call it without PATH= prefixes.

* docs(sample-app): zero-config just test; dotenv-load for persistence

Drop the expectation that users prefix commands with PATH=, ANDROID_HOME=,
or AVD=. `just test` now works as-is; optional knobs can be pinned in a
.env file alongside the justfile.

* fix(sample-app): auto-detect ANDROID_HOME for Gradle tasks

The Go CLI finds the SDK itself, but AGP still needs ANDROID_HOME to
resolve `sdk.dir`. The justfile now resolves it from env or canonical
install paths before invoking ./gradlew, so `just install` works out
of the box on a standard Android SDK setup.

* gitignore runs directory for sample app

Makefile

@@ -15,7 +15,7 @@ DOCS_SRC := $(shell find docs -type f -name '*.md' -not -path 'docs/_*')
 DOCS_OUT := $(patsubst docs/%.md,build/site/%.html,$(DOCS_SRC))
 DOCS_TEMPLATE := docs/_template/page.html
 
-.PHONY: bootstrap proto sidecar sdk-android sdk-android-publish uatu test test-go test-kotlin test-spec-api docs clean release-cli release-android-local release-npm-dry
+.PHONY: bootstrap proto sidecar sdk-android sdk-android-publish uatu install test test-go test-kotlin test-spec-api docs clean release-cli release-android-local release-npm-dry
 
 bootstrap:
 	$(GO) mod download
@@ -42,6 +42,14 @@ $(UATU_BIN): $(SIDECAR_JAR)
 	cp $(SIDECAR_JAR) $(SIDECAR_EMBED)
 	$(GO) build -tags withsidecar -o $(UATU_BIN) ./cmd/uatu
 
+# Installs `uatu` into $GOBIN (or $GOPATH/bin) so it's directly on PATH for
+# anyone with a standard Go toolchain setup.
+install: $(SIDECAR_JAR)
+	mkdir -p $(dir $(SIDECAR_EMBED))
+	cp $(SIDECAR_JAR) $(SIDECAR_EMBED)
+	$(GO) install -tags withsidecar ./cmd/uatu
+	@dest="$$($(GO) env GOBIN)"; [ -n "$$dest" ] || dest="$$($(GO) env GOPATH)/bin"; echo "installed uatu to $$dest"
+
 $(SIDECAR_JAR):
 	$(MAKE) sidecar
 

bug.md

@@ -0,0 +1,49 @@
+# Dokka / Java 25 publish failure
+
+## What fails
+
+Running `./gradlew :sdk-android:publishToMavenLocal` (or any task that triggers `javaDocReleaseGeneration`) on a JDK 25 host crashes with:
+
+```
+Execution failed for task ':sdk-android:javaDocReleaseGeneration'.
+> A failure occurred while executing com.android.build.gradle.tasks.JavaDocGenerationTask$DokkaWorkAction
+...
+Caused by: java.lang.IllegalArgumentException: 25.0.2
+    at com.intellij.util.lang.JavaVersion.parse(JavaVersion.java:298)
+```
+
+## Why it happens
+
+The publish flow is:
+
+1. `com.vanniktech.maven.publish:0.30.0` (declared in `sdk/android/build.gradle.kts:7`) configures an `AndroidSingleVariantLibrary` with `publishJavadocJar = true`.
+2. That wires AGP's `JavaDocGenerationTask` into the release publication. The task runs Dokka in a `WorkAction`.
+3. Dokka ships a vendored copy of IntelliJ's platform SDK. When it boots, it probes the JDK version by calling `com.intellij.util.lang.JavaVersion.parse(System.getProperty("java.version"))`.
+4. On the host JDK the property is literally the string `"25.0.2"`. Dokka's bundled `JavaVersion.parse` (an older IntelliJ build) only understands the legacy patterns (`1.8.0_x`, `9`, `11.0.x`, etc.) and refuses version 25's format, throwing `IllegalArgumentException: 25.0.2`.
+5. The worker dies, Gradle marks `javaDocReleaseGeneration` failed, and the whole publish lifecycle aborts before any POM or AAR is written.
+
+## Why it's latent in CI
+
+CI runs on JDK 17 per `build.gradle.kts` compile targets and whatever `actions/setup-java` installs. `"17.0.x"` matches the old format, so the bundled `JavaVersion.parse` doesn't blow up. The bug only surfaces on developer machines running JDK 21+ where the version string format changed, and reliably on JDK 25.
+
+## Workaround
+
+```sh
+./gradlew :sdk-android:publishToMavenLocal -x javaDocReleaseGeneration
+```
+
+The AAR, sources jar, and POM publish cleanly; only the Javadoc jar is skipped. That produces a usable `0.0.0-dev` artifact for local testing but is not a substitute for a real release publish, since Maven Central validation requires the Javadoc jar.
+
+## Possible fixes
+
+1. **Bump the `vanniktech.maven.publish` plugin to a version that ships a newer Dokka.** The `0.30.0` version pinned here is from mid-2024. Newer releases (0.33+) bundle Dokka 2.x, which has rewritten the JDK detection path and handles modern version strings. One line in `sdk/android/build.gradle.kts`, no build config change. Requires verifying the plugin's breaking changes for the publish config.
+
+2. **Pin a compatible Dokka directly.** Add `id("org.jetbrains.dokka") version "1.9.20"` (or later) so the plugin picks up Dokka's own fix for IntelliJ `JavaVersion.parse`. Slightly more invasive; you now manage Dokka independently from the publish plugin.
+
+3. **Force a JDK toolchain for the javadoc task.** Add a `java { toolchain { languageVersion = JavaLanguageVersion.of(17) } }` block scoped to the SDK module (or use `tasks.withType<JavaDocGenerationTask> { javaLauncher.set(...) }`). Gradle downloads JDK 17 and runs Dokka under it regardless of the host JDK. Robust but adds a toolchain dependency to every dev machine's first build.
+
+4. **Don't generate a Javadoc jar.** Flip `publishJavadocJar = false` in the vanniktech config. Kills the problem by removing the failing path. Not viable for Maven Central release (they require a Javadoc jar).
+
+## Recommendation
+
+Option 1. Smallest diff, addresses the root cause, keeps the publish pipeline intact for Central releases, and newer plugin versions also bring AGP 8.x compatibility improvements.

cmd/uatu/android_env.go

@@ -0,0 +1,235 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"slices"
+	"strings"
+	"time"
+)
+
+// ensureDevice makes sure an Android device is ready for adb commands.
+// Resolution order:
+//   - if an adb device is already online, use it;
+//   - else if avdName is set, validate and boot it;
+//   - else if exactly one AVD exists locally, boot it;
+//   - else fail with a helpful message listing the available AVDs.
+func ensureDevice(ctx context.Context, avdName string, stdout io.Writer) error {
+	devices, err := listAdbDevices(ctx)
+	if err != nil {
+		return fmt.Errorf("list adb devices: %w", err)
+	}
+	if len(devices) > 0 {
+		fmt.Fprintf(stdout, "using connected device: %s\n", devices[0])
+		return nil
+	}
+	avds, err := listAVDs(ctx)
+	if err != nil {
+		return fmt.Errorf("list AVDs: %w", err)
+	}
+	target, err := pickAVD(avdName, avds)
+	if err != nil {
+		return err
+	}
+	fmt.Fprintf(stdout, "booting AVD %q...\n", target)
+	if err := bootAVD(ctx, target); err != nil {
+		return fmt.Errorf("boot AVD %q: %w", target, err)
+	}
+	if err := waitForBoot(ctx, 180*time.Second); err != nil {
+		return fmt.Errorf("wait for AVD boot: %w", err)
+	}
+	fmt.Fprintf(stdout, "AVD %q ready\n", target)
+	return nil
+}
+
+func pickAVD(requested string, available []string) (string, error) {
+	if requested != "" {
+		if !slices.Contains(available, requested) {
+			return "", fmt.Errorf("AVD %q does not exist (available: %s)", requested, strings.Join(available, ", "))
+		}
+		return requested, nil
+	}
+	switch len(available) {
+	case 0:
+		return "", fmt.Errorf("no android device connected and no AVD found; create one in Android Studio or `avdmanager create avd`")
+	case 1:
+		return available[0], nil
+	default:
+		return "", fmt.Errorf("no android device connected and multiple AVDs available (%s); pick one with --avd", strings.Join(available, ", "))
+	}
+}
+
+func listAdbDevices(ctx context.Context) ([]string, error) {
+	adb, err := adbBinary()
+	if err != nil {
+		return nil, err
+	}
+	output, err := exec.CommandContext(ctx, adb, "devices").Output()
+	if err != nil {
+		return nil, err
+	}
+	return parseAdbDevices(string(output)), nil
+}
+
+func parseAdbDevices(output string) []string {
+	var serials []string
+	scanner := bufio.NewScanner(strings.NewReader(output))
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "List of devices") {
+			continue
+		}
+		fields := strings.Fields(line)
+		if len(fields) >= 2 && fields[1] == "device" {
+			serials = append(serials, fields[0])
+		}
+	}
+	return serials
+}
+
+func listAVDs(ctx context.Context) ([]string, error) {
+	emulator, err := emulatorBinary()
+	if err != nil {
+		return nil, err
+	}
+	output, err := exec.CommandContext(ctx, emulator, "-list-avds").Output()
+	if err != nil {
+		return nil, err
+	}
+	return parseAVDList(string(output)), nil
+}
+
+func adbBinary() (string, error)      { return findAndroidTool("adb", "platform-tools") }
+func emulatorBinary() (string, error) { return findAndroidTool("emulator", "emulator") }
+
+// findAndroidTool locates a binary from the Android SDK. It checks PATH,
+// then $ANDROID_HOME/<subdir>/<name> and $ANDROID_SDK_ROOT/<subdir>/<name>,
+// then the canonical install locations used by Android Studio and Homebrew.
+// Returns a descriptive error when nothing works, so the user knows to set
+// $ANDROID_HOME instead of getting a raw "executable file not found".
+func findAndroidTool(name, subdir string) (string, error) {
+	if path, err := exec.LookPath(name); err == nil {
+		return path, nil
+	}
+	var tried []string
+	for _, root := range androidSDKCandidates() {
+		candidate := filepath.Join(root, subdir, name)
+		if info, err := os.Stat(candidate); err == nil && !info.IsDir() {
+			return candidate, nil
+		}
+		tried = append(tried, candidate)
+	}
+	return "", fmt.Errorf("could not locate %q: not on PATH and not under any known Android SDK root (set $ANDROID_HOME to point at your SDK; tried %v)", name, tried)
+}
+
+func androidSDKCandidates() []string {
+	var roots []string
+	seen := map[string]bool{}
+	addRoot := func(path string) {
+		if path == "" || seen[path] {
+			return
+		}
+		seen[path] = true
+		roots = append(roots, path)
+	}
+	addRoot(os.Getenv("ANDROID_HOME"))
+	addRoot(os.Getenv("ANDROID_SDK_ROOT"))
+	if home, err := os.UserHomeDir(); err == nil {
+		addRoot(filepath.Join(home, "Library", "Android", "sdk"))
+		addRoot(filepath.Join(home, "Android", "Sdk"))
+	}
+	addRoot("/opt/homebrew/share/android-commandlinetools")
+	addRoot("/usr/local/share/android-commandlinetools")
+	return roots
+}
+
+func parseAVDList(output string) []string {
+	var avds []string
+	scanner := bufio.NewScanner(strings.NewReader(output))
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "INFO") {
+			continue
+		}
+		avds = append(avds, line)
+	}
+	return avds
+}
+
+func bootAVD(_ context.Context, name string) error {
+	emulator, err := emulatorBinary()
+	if err != nil {
+		return err
+	}
+	command := exec.Command(emulator, "-avd", name, "-no-snapshot-save", "-no-audio", "-no-boot-anim")
+	if err := command.Start(); err != nil {
+		return err
+	}
+	go func() { _ = command.Wait() }()
+	return nil
+}
+
+func waitForBoot(ctx context.Context, timeout time.Duration) error {
+	deadline, cancel := context.WithTimeout(ctx, timeout)
+	defer cancel()
+	ticker := time.NewTicker(2 * time.Second)
+	defer ticker.Stop()
+	for {
+		if completed, _ := bootCompleted(deadline); completed {
+			return nil
+		}
+		select {
+		case <-deadline.Done():
+			return deadline.Err()
+		case <-ticker.C:
+		}
+	}
+}
+
+// envWithAndroidPlatformTools returns env with the directory containing adb
+// prepended to PATH, so child processes (the sidecar) can invoke adb even
+// when the user hasn't set up their shell PATH.
+func envWithAndroidPlatformTools(env []string) []string {
+	adb, err := adbBinary()
+	if err != nil {
+		return env
+	}
+	adbDir := filepath.Dir(adb)
+	result := make([]string, 0, len(env))
+	found := false
+	for _, entry := range env {
+		if current, ok := strings.CutPrefix(entry, "PATH="); ok {
+			if !pathContains(current, adbDir) {
+				entry = "PATH=" + adbDir + string(os.PathListSeparator) + current
+			}
+			found = true
+		}
+		result = append(result, entry)
+	}
+	if !found {
+		result = append(result, "PATH="+adbDir)
+	}
+	return result
+}
+
+func pathContains(path, directory string) bool {
+	return slices.Contains(strings.Split(path, string(os.PathListSeparator)), directory)
+}
+
+func bootCompleted(ctx context.Context) (bool, error) {
+	adb, err := adbBinary()
+	if err != nil {
+		return false, err
+	}
+	output, err := exec.CommandContext(ctx, adb, "shell", "getprop", "sys.boot_completed").Output()
+	if err != nil {
+		return false, err
+	}
+	return strings.TrimSpace(string(output)) == "1", nil
+}
+

cmd/uatu/android_env_test.go

@@ -0,0 +1,93 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestParseAdbDevices_OnlineOnly(t *testing.T) {
+	output := `List of devices attached
+emulator-5554	device
+emulator-5556	offline
+physical-abc	device
+`
+
+	got := parseAdbDevices(output)
+	want := []string{"emulator-5554", "physical-abc"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+}
+
+func TestParseAdbDevices_Empty(t *testing.T) {
+	output := "List of devices attached\n\n"
+
+	got := parseAdbDevices(output)
+	if len(got) != 0 {
+		t.Fatalf("got %v, want empty", got)
+	}
+}
+
+func TestParseAVDList_DropsInfoLines(t *testing.T) {
+	output := `INFO    | Storing crashdata in: /tmp/x
+Medium_Phone_API_36.0
+uatu_test
+`
+
+	got := parseAVDList(output)
+	want := []string{"Medium_Phone_API_36.0", "uatu_test"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+}
+
+func TestPickAVD_ExplicitName(t *testing.T) {
+	got, err := pickAVD("Pixel_7", []string{"Pixel_7", "uatu_test"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "Pixel_7" {
+		t.Fatalf("got %q, want Pixel_7", got)
+	}
+}
+
+func TestPickAVD_ExplicitMissing(t *testing.T) {
+	_, err := pickAVD("Nope", []string{"Pixel_7"})
+	if err == nil {
+		t.Fatal("expected error")
+	}
+}
+
+func TestPickAVD_SingleAvailable(t *testing.T) {
+	got, err := pickAVD("", []string{"uatu_test"})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != "uatu_test" {
+		t.Fatalf("got %q, want uatu_test", got)
+	}
+}
+
+func TestPickAVD_AmbiguousWithoutHint(t *testing.T) {
+	_, err := pickAVD("", []string{"a", "b"})
+	if err == nil {
+		t.Fatal("expected error when multiple AVDs and no --avd")
+	}
+}
+
+func TestPickAVD_NoneAvailable(t *testing.T) {
+	_, err := pickAVD("", nil)
+	if err == nil {
+		t.Fatal("expected error when no AVDs exist")
+	}
+}
+
+func TestPathContains(t *testing.T) {
+	path := "/usr/bin:/opt/tools:/usr/local/bin"
+	if !pathContains(path, "/opt/tools") {
+		t.Error("expected /opt/tools in PATH")
+	}
+	if pathContains(path, "/nope") {
+		t.Error("did not expect /nope in PATH")
+	}
+}

cmd/uatu/main.go

@@ -46,7 +46,7 @@ func parseTestArgs(args []string, stderr io.Writer) (testOptions, error) {
 	flagSet.StringVar(&options.bundleID, "bundle-id", "", "target app bundle ID (required)")
 	flagSet.StringVar(&options.launcherActivity, "launcher-activity", "", "optional <pkg>/<activity> to launch (overrides default resolution)")
 	flagSet.StringVar(&options.platform, "platform", "android", "target platform: android (ios deferred)")
-	flagSet.StringVar(&options.avd, "avd", "", "Android AVD name (required on android)")
+	flagSet.StringVar(&options.avd, "avd", "", "Android AVD name to boot if no device is connected")
 	flagSet.DurationVar(&options.duration, "duration", 5*time.Minute, "total test duration")
 	flagSet.Int64Var(&options.seed, "seed", 0, "RNG seed (0 = random)")
 	flagSet.StringVar(&options.output, "output", "./runs", "output directory for traces")
@@ -59,9 +59,6 @@ func parseTestArgs(args []string, stderr io.Writer) (testOptions, error) {
 	if options.bundleID == "" {
 		return testOptions{}, errors.New("--bundle-id is required")
 	}
-	if options.platform == "android" && options.avd == "" {
-		return testOptions{}, errors.New("--avd is required on android")
-	}
 	if options.platform != "android" {
 		return testOptions{}, fmt.Errorf("unsupported platform: %q (only android in v0.1)", options.platform)
 	}

cmd/uatu/main_test.go

@@ -66,10 +66,13 @@ func TestParseTestArgs_RequiresBundleID(t *testing.T) {
 	}
 }
 
-func TestParseTestArgs_RequiresAVDOnAndroid(t *testing.T) {
+func TestParseTestArgs_AVDIsOptional(t *testing.T) {
-	_, err := parseTestArgs([]string{"--spec", "s.ts", "--bundle-id", "com.example"}, io.Discard)
+	options, err := parseTestArgs([]string{"--spec", "s.ts", "--bundle-id", "com.example"}, io.Discard)
-	if err == nil || !strings.Contains(err.Error(), "--avd") {
+	if err != nil {
-		t.Fatalf("expected missing --avd error, got %v", err)
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if options.avd != "" {
+		t.Fatalf("avd default: got %q, want empty", options.avd)
 	}
 }
 
@@ -129,16 +132,25 @@ func TestRun_Doctor(t *testing.T) {
 	}
 }
 
-func TestRun_TestSubcommand_ReportsBundleErrorForMissingSpec(t *testing.T) {
+func TestRun_TestSubcommand_PipelineErrors(t *testing.T) {
-	// Without a real spec file the pipeline should fail at the bundle step
+	// Without a real spec, a real device, or a bootable AVD the pipeline
-	// rather than panicking — proves the flag wiring reaches the runner.
+	// must surface a specific error rather than panicking — proves the flag
+	// wiring reaches the runner.
 	err := run([]string{
 		"uatu", "test",
 		"--spec", "definitely-missing-spec.ts",
 		"--bundle-id", "com.example",
-		"--avd", "Pixel_5_API_33",
+		"--avd", "definitely-missing-avd",
 	}, io.Discard, io.Discard)
-	if err == nil || !strings.Contains(err.Error(), "bundle") {
+	if err == nil {
-		t.Errorf("expected bundle error, got %v", err)
+		t.Fatal("expected error, got nil")
+	}
+	message := err.Error()
+	ok := strings.Contains(message, "bundle") ||
+		strings.Contains(message, "device") ||
+		strings.Contains(message, "AVD") ||
+		strings.Contains(message, "emulator")
+	if !ok {
+		t.Errorf("expected pipeline error (bundle/device/AVD/emulator), got %v", err)
 	}
 }

cmd/uatu/test_run.go

@@ -28,17 +28,22 @@ const (
 )
 
 func runTestPipeline(ctx context.Context, options testOptions, stdout io.Writer) error {
-	specApiPath, err := resolveSpecAPIPath(options.spec)
+	if options.platform == "android" {
-	if err != nil {
+		if err := ensureDevice(ctx, options.avd, stdout); err != nil {
 			return err
 		}
+	}
+	aliases := map[string]string{}
+	if specApiPath := resolveSpecAPIPath(options.spec); specApiPath != "" {
+		aliases["@uatu/spec"] = specApiPath
+	}
 	bundle, err := bundler.Bundle(bundler.Options{
 		EntryFile: options.spec,
 		Defines: map[string]string{
 			"UATU_TEST_PHONE": os.Getenv("UATU_TEST_PHONE"),
 			"UATU_TEST_OTP":   os.Getenv("UATU_TEST_OTP"),
 		},
-		Aliases: map[string]string{"@uatu/spec": specApiPath},
+		Aliases: aliases,
 	})
 	if err != nil {
 		return fmt.Errorf("bundle spec: %w", err)
@@ -62,6 +67,7 @@ func runTestPipeline(ctx context.Context, options testOptions, stdout io.Writer)
 	)
 	sidecarCommand.Stdout = stdout
 	sidecarCommand.Stderr = stdout
+	sidecarCommand.Env = envWithAndroidPlatformTools(os.Environ())
 	if err := sidecarCommand.Start(); err != nil {
 		return fmt.Errorf("spawn sidecar: %w", err)
 	}
@@ -193,10 +199,11 @@ func runTestPipeline(ctx context.Context, options testOptions, stdout io.Writer)
 	return nil
 }
 
-// resolveSpecAPIPath finds pkg/spec-api/src/index.ts relative to the spec
+// resolveSpecAPIPath returns the path to pkg/spec-api/src/index.ts inside
-// file or the current working directory so the bundler can resolve
+// a uatu source checkout, searched upward from the spec file and the cwd.
-// `@uatu/spec` imports.
+// Returns "" when not found, in which case esbuild resolves @uatu/spec via
-func resolveSpecAPIPath(specPath string) (string, error) {
+// node_modules the way a downstream user's project would.
+func resolveSpecAPIPath(specPath string) string {
 	candidates := []string{}
 	if absoluteSpec, err := filepath.Abs(specPath); err == nil {
 		directory := filepath.Dir(absoluteSpec)
@@ -214,10 +221,10 @@ func resolveSpecAPIPath(specPath string) (string, error) {
 	}
 	for _, candidate := range candidates {
 		if _, err := os.Stat(candidate); err == nil {
-			return candidate, nil
+			return candidate
 		}
 	}
-	return "", fmt.Errorf("could not locate pkg/spec-api/src/index.ts (searched %d paths)", len(candidates))
+	return ""
 }
 
 func pickFreePort() (int, error) {
@@ -230,10 +237,18 @@ func pickFreePort() (int, error) {
 }
 
 func adbReverse(socket string, port int) error {
-	command := exec.Command("adb", "reverse", "localabstract:"+socket, fmt.Sprintf("tcp:%d", port))
+	adb, err := adbBinary()
+	if err != nil {
+		return err
+	}
+	command := exec.Command(adb, "reverse", "localabstract:"+socket, fmt.Sprintf("tcp:%d", port))
 	return command.Run()
 }
 
 func adbReverseRemove(socket string) error {
-	return exec.Command("adb", "reverse", "--remove", "localabstract:"+socket).Run()
+	adb, err := adbBinary()
+	if err != nil {
+		return err
+	}
+	return exec.Command(adb, "reverse", "--remove", "localabstract:"+socket).Run()
 }

cmd/uatu/test_run_test.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestResolveSpecAPIPath_FindsUpwardSibling(t *testing.T) {
+	root := t.TempDir()
+	apiPath := filepath.Join(root, "pkg", "spec-api", "src", "index.ts")
+	if err := os.MkdirAll(filepath.Dir(apiPath), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(apiPath, []byte("export {}"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	specPath := filepath.Join(root, "examples", "app", "spec.ts")
+	if err := os.MkdirAll(filepath.Dir(specPath), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(specPath, []byte(""), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	got := resolveSpecAPIPath(specPath)
+	if got != apiPath {
+		t.Fatalf("got %q, want %q", got, apiPath)
+	}
+}
+
+func TestResolveSpecAPIPath_ReturnsEmptyWhenMissing(t *testing.T) {
+	root := t.TempDir()
+	specPath := filepath.Join(root, "spec.ts")
+	if err := os.WriteFile(specPath, []byte(""), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	cwd, err := os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = os.Chdir(cwd) })
+	if err := os.Chdir(root); err != nil {
+		t.Fatal(err)
+	}
+
+	got := resolveSpecAPIPath(specPath)
+	if got != "" {
+		t.Fatalf("got %q, want empty (no uatu source tree reachable)", got)
+	}
+}

docs/manual/getting-started.md

@@ -53,7 +53,8 @@ dependencies {
 The repo ships a working sample at `examples/sample-app`. From that directory:
 
 ```sh
-./gradlew :sample-app:installDebug
+npm install
+(cd android && ./gradlew installDebug)
 uatu test \
   --spec spec.ts \
   --bundle-id dev.uatu.sample \

examples/sample-app/.gitignore

@@ -0,0 +1 @@
+/runs

examples/sample-app/README.md

@@ -0,0 +1,50 @@
+# uatu sample app
+
+Tiny Android app wired to the uatu SDK, plus a TypeScript spec that drives it.
+Use it as a reference for integrating uatu into your own app.
+
+## Prerequisites
+
+- `uatu` CLI on `PATH` (see [getting started](https://priyanshujain.github.io/uatu/manual/getting-started.html))
+- Android SDK installed (uatu auto-discovers `adb` and `emulator` under
+  `$ANDROID_HOME`, `~/Library/Android/sdk`, or the Homebrew cask; nothing to
+  export if you use a standard install)
+- `just` task runner
+
+## Install the app
+
+```sh
+just install
+```
+
+## Run a test
+
+```sh
+just test
+```
+
+If no device is connected, uatu boots the single AVD it finds. With multiple
+AVDs, pick one:
+
+```sh
+just AVD=Pixel_7 test
+```
+
+Persistent settings can live in `.env` alongside the justfile:
+
+```
+AVD=Pixel_7
+DURATION=5m
+```
+
+Traces land in `./runs/<timestamp>/`.
+
+## How the pieces connect
+
+- `android/build.gradle.kts` depends on `io.github.priyanshujain:sdk-android` from
+  Maven Central
+- `android/src/main/kotlin/.../SampleApplication.kt` calls `Uatu.start(this)` and
+  registers snapshot extractors (`app_state`, `click_count`)
+- `spec.ts` imports `@uatu/spec` (see `package.json`), reads those snapshots,
+  asserts properties on them, and weights the actions the fuzzer picks from
+- `just test` invokes `uatu test` against the installed APK on the named AVD

examples/sample-app/android/build.gradle.kts

@@ -3,6 +3,8 @@ plugins {
     kotlin("android") version "2.1.21"
 }
 
+val uatuVersion = findProperty("uatu.version") as String? ?: "0.0.0-dev"
+
 android {
     namespace = "dev.uatu.sample"
     compileSdk = 35
@@ -12,7 +14,7 @@ android {
         minSdk = 24
         targetSdk = 35
         versionCode = 1
-        versionName = findProperty("uatu.version") as String? ?: "0.0.0-dev"
+        versionName = uatuVersion
     }
 
     compileOptions {
@@ -32,5 +34,5 @@ android {
 }
 
 dependencies {
-    implementation(project(":sdk-android"))
+    implementation("io.github.priyanshujain:sdk-android:$uatuVersion")
 }

examples/sample-app/android/gradle.properties

@@ -0,0 +1,10 @@
+org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
+org.gradle.parallel=true
+org.gradle.caching=true
+kotlin.code.style=official
+android.useAndroidX=true
+
+# Pin the uatu SDK version consumed by this sample. Override with
+# `-Puatu.version=<version>` or edit build.gradle.kts once a stable release is
+# available on Maven Central.
+uatu.version=0.0.0-dev

examples/sample-app/android/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.4.1-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists

examples/sample-app/android/gradlew

@@ -0,0 +1,248 @@
+#!/bin/sh
+
+#
+# Copyright © 2015 the original authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+##############################################################################
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/2d6327017519d23b96af35865dc997fcb544fb40/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
+##############################################################################
+
+# Attempt to set APP_HOME
+
+# Resolve links: $0 may be a link
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
+done
+
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD=maximum
+
+warn () {
+    echo "$*"
+} >&2
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+} >&2
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
+esac
+
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD=$JAVA_HOME/jre/sh/java
+    else
+        JAVACMD=$JAVA_HOME/bin/java
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+fi
+
+# Increase the maximum file descriptors if we can.
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
+    esac
+fi
+
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
+
+exec "$JAVACMD" "$@"

examples/sample-app/android/gradlew.bat

@@ -0,0 +1,93 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
+
+@if "%DEBUG%"=="" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if %ERRORLEVEL% equ 0 goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto execute
+
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
+
+goto fail
+
+:execute
+@rem Setup the command line
+
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
+
+:end
+@rem End local scope for the variables with windows NT shell
+if %ERRORLEVEL% equ 0 goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

examples/sample-app/android/settings.gradle.kts

@@ -0,0 +1,18 @@
+pluginManagement {
+    repositories {
+        gradlePluginPortal()
+        google()
+        mavenCentral()
+    }
+}
+
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+        mavenLocal()
+    }
+}
+
+rootProject.name = "uatu-sample"

examples/sample-app/justfile

@@ -1,48 +1,74 @@
 set shell := ["bash", "-cu"]
+set dotenv-load := true
 
-repo_root := absolute_path(justfile_directory() / ".." / "..")
+uatu     := env_var_or_default("UATU", "uatu")
-uatu      := env_var_or_default("UATU", repo_root / "bin/uatu")
 avd      := env_var_or_default("AVD", "")
 duration := env_var_or_default("DURATION", "1m")
 seed     := env_var_or_default("SEED", "0")
-output    := env_var_or_default("OUTPUT", repo_root / "runs")
+output   := env_var_or_default("OUTPUT", justfile_directory() / "runs")
+android  := justfile_directory() / "android"
 
 default:
     @just --list
 
+# Resolve ANDROID_HOME from the env or a short list of canonical install
+# locations, so Gradle can find the Android SDK without the user having to
+# export anything.
+_android-home:
+    #!/usr/bin/env bash
+    set -euo pipefail
+    if [[ -n "${ANDROID_HOME:-}" && -d "$ANDROID_HOME" ]]; then
+      echo "$ANDROID_HOME"; exit 0
+    fi
+    if [[ -n "${ANDROID_SDK_ROOT:-}" && -d "$ANDROID_SDK_ROOT" ]]; then
+      echo "$ANDROID_SDK_ROOT"; exit 0
+    fi
+    for candidate in \
+      "$HOME/Library/Android/sdk" \
+      "$HOME/Android/Sdk" \
+      "/opt/homebrew/share/android-commandlinetools" \
+      "/usr/local/share/android-commandlinetools"; do
+      if [[ -d "$candidate" ]]; then
+        echo "$candidate"; exit 0
+      fi
+    done
+    echo "could not locate Android SDK (set ANDROID_HOME)" >&2
+    exit 1
+
 # Build and install the sample APK on a running emulator/device.
 install:
-    cd {{repo_root}} && ./gradlew :sample-app:installDebug
+    #!/usr/bin/env bash
+    set -euo pipefail
+    export ANDROID_HOME="$(just _android-home)"
+    cd {{android}} && ./gradlew installDebug
 
 # Remove the sample APK from the connected device.
 uninstall:
-    cd {{repo_root}} && ./gradlew :sample-app:uninstallDebug
+    #!/usr/bin/env bash
+    set -euo pipefail
+    export ANDROID_HOME="$(just _android-home)"
+    cd {{android}} && ./gradlew uninstallDebug
 
-# Build the uatu CLI (writes to repo's bin/uatu).
+# Remove the gradle build directory.
-uatu:
+clean:
-    make -C {{repo_root}} uatu
+    #!/usr/bin/env bash
+    set -euo pipefail
+    export ANDROID_HOME="$(just _android-home)"
+    cd {{android}} && ./gradlew clean
 
-# Run the Go tests that bundle and exercise spec.ts (no device required).
+# Run 'uatu test' against the sample app. Uses a connected device if one is
-verify:
+# online, otherwise boots AVD=<name> if provided.
-    cd {{repo_root}} && go test ./internal/verifier/ -run TestSampleAppSpec
-
-# Run 'uatu test' against the sample app. AVD=<name> is required.
 test:
     #!/usr/bin/env bash
     set -euo pipefail
-    if [[ -z "{{avd}}" ]]; then
+    avd_flag=()
-      echo "AVD is required (usage: just AVD=<name> test)" >&2
+    if [[ -n "{{avd}}" ]]; then
-      exit 1
+      avd_flag=(--avd "{{avd}}")
     fi
-    if [[ ! -x "{{uatu}}" ]]; then just uatu; fi
     "{{uatu}}" test \
       --spec "{{justfile_directory()}}/spec.ts" \
       --bundle-id dev.uatu.sample \
-      --avd "{{avd}}" \
+      "${avd_flag[@]}" \
       --duration "{{duration}}" \
       --seed "{{seed}}" \
       --output "{{output}}"
-
-# Remove the gradle build directory for the sample app.
-clean:
-    cd {{repo_root}} && ./gradlew :sample-app:clean

examples/sample-app/package-lock.json

@@ -0,0 +1,28 @@
+{
+  "name": "uatu-sample",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "uatu-sample",
+      "devDependencies": {
+        "@uatu/spec": "file:../../pkg/spec-api"
+      }
+    },
+    "../../pkg/spec-api": {
+      "name": "@uatu/spec",
+      "version": "0.0.0-dev",
+      "dev": true,
+      "license": "Apache-2.0",
+      "devDependencies": {
+        "@types/node": "^22.7.5",
+        "tsx": "^4.21.0",
+        "typescript": "^5.9.3"
+      }
+    },
+    "node_modules/@uatu/spec": {
+      "resolved": "../../pkg/spec-api",
+      "link": true
+    }
+  }
+}

examples/sample-app/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "uatu-sample",
+  "private": true,
+  "description": "Minimal uatu integration example.",
+  "devDependencies": {
+    "@uatu/spec": "file:../../pkg/spec-api"
+  }
+}

sdk/android/src/main/kotlin/dev/uatu/sdk/Uatu.kt

@@ -1,6 +1,7 @@
 package dev.uatu.sdk
 
 import android.app.Application
+import android.util.Log
 
 data class Configuration(
     val socketName: String = "uatu-agent",
@@ -9,6 +10,7 @@ data class Configuration(
 
 object Uatu {
     const val VERSION: String = "0.0.1"
+    private const val LOG_TAG = "Uatu"
 
     @Volatile private var runtime: UatuRuntime? = null
 
@@ -24,6 +26,7 @@ object Uatu {
         )
         newRuntime.start()
         runtime = newRuntime
+        Log.i(LOG_TAG, "SDK started (package=${application.packageName} socket=${configuration.socketName})")
     }
 
     fun extract(name: String, function: () -> Any?) {

settings.gradle.kts

@@ -19,5 +19,3 @@ rootProject.name = "uatu"
 include(":sidecar")
 include(":sdk-android")
 project(":sdk-android").projectDir = file("sdk/android")
-include(":sample-app")
-project(":sample-app").projectDir = file("examples/sample-app/android")

sidecar/src/main/kotlin/dev/uatu/sidecar/DriverBackend.kt

@@ -36,13 +36,47 @@ class StubDriverBackend(private val platform: String) : DriverBackend {
         if (clearState) {
             runAdb(listOf("shell", "pm", "clear", bundleId))
         }
-        if (launcherActivity.isNotEmpty()) {
+        val component = when {
-            val component = if (launcherActivity.contains('/')) launcherActivity else "$bundleId/$launcherActivity"
+            launcherActivity.isEmpty() -> "$bundleId/${resolveLauncherActivity(bundleId)}"
-            runAdb(listOf("shell", "am", "start", "-n", component))
+            launcherActivity.contains('/') -> launcherActivity
-        } else {
+            else -> "$bundleId/$launcherActivity"
-            // `monkey` uses PackageManager.getLaunchIntentForPackage, which
+        }
-            // picks the canonical default launcher.
+        runAdb(listOf("shell", "am", "start", "-W", "-n", component))
-            runAdb(listOf("shell", "monkey", "-p", bundleId, "-c", "android.intent.category.LAUNCHER", "1"))
+    }
+
+    private fun resolveLauncherActivity(bundleId: String): String {
+        val output = captureAdb(
+            listOf(
+                "shell", "cmd", "package", "resolve-activity", "--brief",
+                "-a", "android.intent.action.MAIN",
+                "-c", "android.intent.category.LAUNCHER",
+                bundleId,
+            ),
+        )
+        return parseResolvedActivity(bundleId, output)
+            ?: throw IllegalStateException("could not resolve launcher activity for $bundleId: $output")
+    }
+
+    private fun captureAdb(arguments: List<String>): String {
+        val process = ProcessBuilder(listOf("adb") + arguments).redirectErrorStream(true).start()
+        val output = process.inputStream.bufferedReader().readText()
+        process.waitFor()
+        return output
+    }
+
+    companion object {
+        // parseResolvedActivity extracts the activity name from the output of
+        // `cmd package resolve-activity --brief`. The brief output is two
+        // lines: metadata, then `<pkg>/<activity>`.
+        internal fun parseResolvedActivity(bundleId: String, output: String): String? {
+            val prefix = "$bundleId/"
+            for (line in output.lines()) {
+                val trimmed = line.trim()
+                if (trimmed.startsWith(prefix)) {
+                    return trimmed.removePrefix(prefix)
+                }
+            }
+            return null
         }
     }
 

sidecar/src/test/kotlin/dev/uatu/sidecar/DriverServiceTest.kt

@@ -35,7 +35,13 @@ class DriverServiceTest {
         val backend = StubDriverBackend("android")
         val client = newClient(backend)
 
-        client.launch(LaunchRequest.newBuilder().setBundleId("com.example").setClearState(true).build())
+        client.launch(
+            LaunchRequest.newBuilder()
+                .setBundleId("com.example")
+                .setLauncherActivity(".MainActivity")
+                .setClearState(true)
+                .build(),
+        )
         assertEquals("com.example", backend.lastBundleId)
         assertEquals(1, backend.launchCount)
 

sidecar/src/test/kotlin/dev/uatu/sidecar/ResolveActivityTest.kt

@@ -0,0 +1,39 @@
+package dev.uatu.sidecar
+
+import org.junit.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+
+class ResolveActivityTest {
+
+    @Test fun extractsActivityFromBriefOutput() {
+        val output = """
+            priority=0 preferredOrder=0 match=0x108000 specificIndex=-1 isDefault=false
+            dev.uatu.sample/.MainActivity
+        """.trimIndent()
+
+        val activity = StubDriverBackend.parseResolvedActivity("dev.uatu.sample", output)
+        assertEquals(".MainActivity", activity)
+    }
+
+    @Test fun extractsFullyQualifiedActivity() {
+        val output = "com.example.app/com.example.app.ui.LaunchActivity"
+
+        val activity = StubDriverBackend.parseResolvedActivity("com.example.app", output)
+        assertEquals("com.example.app.ui.LaunchActivity", activity)
+    }
+
+    @Test fun returnsNullWhenPackageNotFound() {
+        val output = "No activity found"
+
+        val activity = StubDriverBackend.parseResolvedActivity("dev.uatu.sample", output)
+        assertNull(activity)
+    }
+
+    @Test fun doesNotMatchDifferentPackagePrefix() {
+        val output = "other.pkg/.MainActivity"
+
+        val activity = StubDriverBackend.parseResolvedActivity("dev.uatu.sample", output)
+        assertNull(activity)
+    }
+}