Clean up supported platform launcher.

This drops our need to have the magic any here, since the index type is explicitly defined, this also means that our compile will now break if a function is renamed that we were depending on :)
GoogleChrome · May 15, 2017 · 320614c · 320614c
1 parent 8a6c1aa
commit 320614c
Showing 1 changed file with 12 additions and 15 deletions.
diff --git a/chrome-launcher/chrome-launcher.ts b/chrome-launcher/chrome-launcher.ts
@@ -33,6 +33,7 @@ const execSync = childProcess.execSync;
 const isWindows = process.platform === 'win32';
 
 export class ChromeLauncher {
+type SupportedPlatforms = 'darwin'|'linux'|'win32';
   prepared = false;
   pollInterval: number = 500;
   autoSelectChrome: boolean;
@@ -75,8 +76,10 @@ export class ChromeLauncher {
     return flags;
   }
 
-  prepare() {
-    switch (process.platform) {
+  private prepare() {
+    const platform = process.platform as SupportedPlatforms;
+
+    switch (platform) {
       case 'darwin':
       case 'linux':
         this.TMP_PROFILE_DIR = unixTmpDir();
@@ -87,7 +90,7 @@ export class ChromeLauncher {
         break;
 
       default:
-        throw new Error('Platform ' + process.platform + ' is not supported');
+        throw new Error(`Platform ${platform} is not supported`);
     }
 
     this.outFile = fs.openSync(`${this.TMP_PROFILE_DIR}/chrome-out.log`, 'a');
@@ -107,19 +110,13 @@ export class ChromeLauncher {
       this.prepare();
     }
 
-    return Promise.resolve()
-        .then(() => {
-          const installations = (<any>chromeFinder)[process.platform]();
-
-          if (installations.length < 1) {
-            return Promise.reject(new Error('No Chrome Installations Found'));
-          } else if (installations.length === 1 || this.autoSelectChrome) {
-            return installations[0];
-          }
+    const installations = await chromeFinder[process.platform as SupportedPlatforms]();
+    if (installations.length === 0) {
+      throw new Error('No Chrome Installations Found');
+    }
 
-          return ask('Choose a Chrome installation to use with Lighthouse', installations);
-        })
-        .then(execPath => this.spawn(execPath));
+    const chromePath = installations[0];
+    return await this.spawn(chromePath);
   }
 
   spawn(execPath: string) {