Add input validations with tests.

src/main.ts

@@ -1,5 +1,7 @@
 import * as core from '@actions/core';
-import { installAndroidSdk } from './sdk-installer'
+import { InputOptions } from "@actions/core/lib/core";
+import { installAndroidSdk } from './sdk-installer';
+import { checkApiLevel, checkTarget, checkAbi, checkHeadless } from './input-validator';
 
 async function run() {
   try {
@@ -8,34 +10,24 @@ async function run() {
       throw new Error('This action is expected to be run within a macOS virtual machine to enable hardware acceleration.');
     }
 
-    // TODO test inputs
-    // TODO test real inputs in test.yml
-
-    // api-level is required
-    // TODO use InputOptions {true}
-    const apiLevel = core.getInput('api-level');
-    // TODO check apiLevel is number and within valid range
+    // API level of the platform and system image
+    const apiLevel = core.getInput('api-level', <InputOptions>{required: true});
+    checkApiLevel(apiLevel);
     console.log(`API level: ${apiLevel}`);
 
-    // target is optional with default
+    // target of the system image
     const target = core.getInput('target');
-    if (target !== 'default' && target !== 'google_apis') {
-      throw new Error(`Target ${target} is unknown. Please use either 'default' or 'google_apis'.`);
-    }
+    checkTarget(target);
     console.log(`target: ${target}`);
 
-    // abi is optional with default
+    // CPU / ABI of the system image
     const abi = core.getInput('abi');
-    if (abi !== 'x86' && abi !== 'x86_64') {
-      throw new Error(`abi ${abi} is unknown (ARM-based emulators are not supported). Please use either 'x86' or 'x86_64'.`);
-    }
+    checkAbi(abi);
     console.log(`cpu/abi: ${abi}`);
 
-    // headless is optional with default
+    // headless mode
     const headless = core.getInput('headless');
-    if (headless !== 'true' && headless !== 'false') {
-      throw new Error(`Input 'headless' should be either 'true' or 'false'.`);
-    }
+    checkHeadless(headless);
     console.log(`headless mode: ${headless}`);
 
     // install SDK