fix(dir): check selenium dir and warn user that the folder does not exist (#17)

closes #11

Author: cnishina

lib/cmds/start.ts

@@ -1,3 +1,4 @@
+import * as fs from 'fs';
 import * as minimist from 'minimist';
 import * as path from 'path';
 import * as os from 'os';
@@ -51,6 +52,16 @@ function start(options: Options) {
       outputDir = path.resolve(Config.getBaseDir(), options[Opt.OUT_DIR].getString());
     }
   }
+
+  try {
+    // check if folder exists
+    fs.statSync(outputDir).isDirectory();
+  } catch (e) {
+    // if the folder does not exist, quit early.
+    logger.warn('the out_dir path ' + outputDir + ' does not exist, run webdriver-manager update');
+    return;
+  }
+
   let chromeLogs: string = null;
   if (options[Opt.CHROME_LOGS].getString()) {
     if (path.isAbsolute(options[Opt.CHROME_LOGS].getString())) {

lib/cmds/status.ts

@@ -1,3 +1,4 @@
+import * as fs from 'fs';
 import * as minimist from 'minimist';
 import * as path from 'path';
 
@@ -37,6 +38,17 @@ function status(options: Options) {
       outputDir = path.resolve(Config.getBaseDir(), options[Opt.OUT_DIR].getString());
     }
   }
+
+  try {
+    // check if folder exists
+    fs.statSync(outputDir).isDirectory();
+  } catch (e) {
+    // if the folder does not exist, quit early.
+    logger.warn('the out_dir path ' + outputDir + ' does not exist');
+    return;
+  }
+
+
   let downloadedBinaries = FileManager.downloadedBinaries(outputDir);
   // log which binaries have been downloaded
   for (let bin in downloadedBinaries) {

lib/files/file_manager.ts

@@ -70,7 +70,13 @@ export class FileManager {
    * @param outputDir The directory where binaries are saved
    * @returns A list of existing files.
    */
-  static getExistngFiles(outputDir: string): string[] { return fs.readdirSync(outputDir); }
+  static getExistngFiles(outputDir: string): string[] {
+    try {
+      return fs.readdirSync(outputDir);
+    } catch (e) {
+      return [];
+    }
+   }
 
   /**
    * For the binary, operating system, and system architecture, look through