Added findRubyVersion tests

__tests__/find-ruby.test.ts

@@ -0,0 +1,59 @@
+import * as io from '@actions/io';
+import fs = require('fs');
+import os = require('os');
+import path = require('path');
+
+const toolDir = path.join(__dirname, 'runner', 'tools');
+const tempDir = path.join(__dirname, 'runner', 'temp');
+
+process.env['RUNNER_TOOLSDIRECTORY'] = toolDir;
+process.env['RUNNER_TEMPDIRECTORY'] = tempDir;
+
+import findRubyVersion from '../src/find-ruby';
+
+describe('find-ruby', () => {
+  beforeAll(async () => {
+    await io.rmRF(toolDir);
+    await io.rmRF(tempDir);
+  });
+
+  afterAll(async () => {
+    try {
+      await io.rmRF(toolDir);
+      await io.rmRF(tempDir);
+    } catch {
+      console.log('Failed to remove test directories');
+    }
+  }, 100000);
+
+  it('findRubyVersion throws if cannot find any version of ruby', async () => {
+    let thrown = false;
+    try {
+      await findRubyVersion('>= 2.4');
+    } catch {
+      thrown = true;
+    }
+    expect(thrown).toBe(true);
+  });
+
+  it('findRubyVersion throws version of ruby is not complete', async () => {
+    let thrown = false;
+    const rubyDir: string = path.join(toolDir, 'Ruby', '2.4.6', os.arch());
+    await io.mkdirP(rubyDir);
+    try {
+      await findRubyVersion('>= 2.4');
+    } catch {
+      thrown = true;
+    }
+    expect(thrown).toBe(true);
+  });
+
+  it('findRubyVersion adds ruby bin to PATH', async () => {
+    const rubyDir: string = path.join(toolDir, 'Ruby', '2.4.6', os.arch());
+    await io.mkdirP(rubyDir);
+    fs.writeFileSync(`${rubyDir}.complete`, 'hello');
+    await findRubyVersion('>= 2.4');
+    const binDir = path.join(rubyDir, 'bin');
+    expect(process.env['PATH']!.startsWith(`${binDir};`)).toBe(true);
+  });
+});