Add support for pinning specific emulator build.

src/input-validator.ts

@@ -28,3 +28,9 @@ export function checkDisableAnimations(disableAnimations: string): void {
     throw new Error(`Input for input.disable-animations should be either 'true' or 'false'.`);
   }
 }
+
+export function checkEmulatorBuild(emulatorBuild: string): void {
+  if (isNaN(Number(emulatorBuild)) || !Number.isInteger(Number(emulatorBuild))) {
+    throw new Error(`Unexpected emulator build: '${emulatorBuild}'.`);
+  }
+}

src/main.ts

@@ -1,6 +1,6 @@
 import * as core from '@actions/core';
 import { installAndroidSdk } from './sdk-installer';
-import { checkApiLevel, checkTarget, checkArch, checkDisableAnimations } from './input-validator';
+import { checkApiLevel, checkTarget, checkArch, checkDisableAnimations, checkEmulatorBuild } from './input-validator';
 import { launchEmulator, killEmulator } from './emulator-manager';
 import * as exec from '@actions/exec';
 import { parseScript } from './script-parser';
@@ -42,6 +42,14 @@ async function run() {
     const disableAnimations = disableAnimationsInput === 'true';
     console.log(`disable animations: ${disableAnimations}`);
 
+    // emulator build
+    const emulatorBuildInput = core.getInput('emulator-build');
+    if (emulatorBuildInput) {
+      checkEmulatorBuild(emulatorBuildInput);
+      console.log(`using emulator build: ${emulatorBuildInput}`);
+    }
+    const emulatorBuild = !emulatorBuildInput ? undefined : emulatorBuildInput;
+
     // custom script to run
     const scriptInput = core.getInput('script', { required: true });
     const scripts = parseScript(scriptInput);
@@ -50,10 +58,10 @@ async function run() {
       console.log(`${script}`);
     });
 
-    try {
-      // install SDK
-      await installAndroidSdk(apiLevel, target, arch);
+    // install SDK
+    await installAndroidSdk(apiLevel, target, arch, emulatorBuild);
 
+    try {
       // launch an emulator
       await launchEmulator(apiLevel, target, arch, profile, emulatorOptions, disableAnimations);
     } catch (error) {

src/sdk-installer.ts

@@ -6,10 +6,20 @@ const BUILD_TOOLS_VERSION = '29.0.2';
  * Installs & updates the Android SDK for the macOS platform, including SDK platform for the chosen API level, latest build tools, platform tools, Android Emulator,
  * and the system image for the chosen API level, CPU arch, and target.
  */
-export async function installAndroidSdk(apiLevel: number, target: string, arch: string): Promise<void> {
+export async function installAndroidSdk(apiLevel: number, target: string, arch: string, emulatorBuild?: string): Promise<void> {
   const sdkmangerPath = `${process.env.ANDROID_HOME}/tools/bin/sdkmanager`;
-  console.log('Installing latest build tools, platform tools, platform, and emulator.');
-  await exec.exec(`sh -c \\"${sdkmangerPath} --install 'build-tools;${BUILD_TOOLS_VERSION}' platform-tools 'platforms;android-${apiLevel}' emulator > /dev/null"`);
+  console.log('Installing latest build tools, platform tools, and platform.');
+  await exec.exec(`sh -c \\"${sdkmangerPath} --install 'build-tools;${BUILD_TOOLS_VERSION}' platform-tools 'platforms;android-${apiLevel}' > /dev/null"`);
+  if (emulatorBuild) {
+    console.log(`Installing emulator build ${emulatorBuild}.`);
+    await exec.exec(`curl -fo emulator.zip https://dl.google.com/android/repository/emulator-darwin-${emulatorBuild}.zip`);
+    await exec.exec(`rm -rf ${process.env.ANDROID_HOME}/emulator`);
+    await exec.exec(`unzip -q emulator.zip -d ${process.env.ANDROID_HOME}`);
+    await exec.exec(`rm -f emulator.zip`);
+  } else {
+    console.log('Installing latest emulator.');
+    await exec.exec(`sh -c \\"${sdkmangerPath} --install emulator > /dev/null"`);
+  }
   console.log('Installing system images.');
   await exec.exec(`sh -c \\"${sdkmangerPath} --install 'system-images;android-${apiLevel};${target};${arch}' > /dev/null"`);
 }