refactor getCommand logical and add test

Author: Zoupers

src/cli.ts

@@ -119,15 +119,23 @@ export class CLI {
         return `${v}\n${cm}\n\n${plugins}`;
     }
 
-    private static getCommand(command: string): string {
+    public static getCommandCandidates(command: string): string[] {
         let validExecExt = [""];
-        let options = CLI.getDefaultSpawnOptions();
         if (platform() === 'win32') {
             validExecExt.push(".bat", ".exe", ".cmd");
         }
-        for (const ext of validExecExt) {
-            let executable = `${command}${ext}`;
-            if (!spawnSync(executable, [], options).error) return executable;
+        return validExecExt.map((ext) => `${command}${ext}`);
+    }
+
+    public static checkSpawnable(command: string): boolean {
+        const result = spawnSync(command, [], CLI.getDefaultSpawnOptions());
+        return result.status === 0 && !result.error;
+    }
+
+    private static getCommand(command: string): string {
+        let possiableCommands = this.getCommandCandidates(command);
+        for (const possiableCommand of possiableCommands) {
+            if (this.checkSpawnable(possiableCommand)) return possiableCommand;
         }
     }
 

test/cli.test.ts

@@ -1,5 +1,8 @@
 import * as assert from 'assert';
 import { CLI } from '../src/cli';
+import path = require('path');
+
+let testCommandsPath = path.join(__dirname, '..', '..', 'test', 'commands');
 
 suite('CLI', () => {
     test('.isPluginInstalled should tell a gauge plugin is installed or not', () => {
@@ -137,4 +140,40 @@ ruby (1.2.0)`;
         assert.ok(!cli.isGaugeVersionGreaterOrEqual('1.3.0'));
         done();
     });
+
+    test('.getCommandCandidates choices all valid', (done) => {
+        let candidates = CLI.getCommandCandidates('test_command');
+        const originalPath = process.env.PATH;
+        process.env.PATH = testCommandsPath;
+        let invalid_candidates = [];
+        try {
+            for (const candidate of candidates) {
+                if (!CLI.checkSpawnable(candidate)) {
+                    invalid_candidates.push(candidate);
+                }
+            }
+            assert.ok(invalid_candidates.length === 0, `invalid candidates: ${invalid_candidates.join(', ')}, those should be valid`);
+        } finally {
+            process.env.PATH = originalPath;
+        }
+        done();
+    });
+
+    test('.getCommandCandidates choices are all not valid', (done) => {
+        let candidates = CLI.getCommandCandidates('test_command_not_found');
+        const originalPath = process.env.PATH;
+        process.env.PATH = testCommandsPath;
+        let valid_candidates = [];
+        try {
+            for (const candidate of candidates) {
+                if (CLI.checkSpawnable(candidate)) {
+                    valid_candidates.push(candidate);
+                }
+            }
+            assert.ok(valid_candidates.length === 0, `valid candidates: ${valid_candidates.join(', ')}, those should not be valid`);
+        } finally {
+            process.env.PATH = originalPath;
+        }
+        done();
+    });
 });

test/commands/test_command

@@ -0,0 +1 @@
+echo success

test/commands/test_command.bat

@@ -0,0 +1 @@
+echo hello

test/commands/test_command.cmd

@@ -0,0 +1,2 @@
+@echo off
+echo success