Adds tests

Author: Maël Nison

__tests__/integration.js

@@ -73,6 +73,58 @@ test('--mutex network', async () => {
   ]);
 });
 
+// Windows doesn't have the "echo" utility
+// Since this feature isn't platform-specific, running them on OSX and Linux only should be fine
+if (process.platform !== 'win32') {
+  test('yarn run <script> --opt', async () => {
+    const cwd = await makeTemp();
+
+    await fs.writeFile(
+      path.join(cwd, 'package.json'),
+      JSON.stringify({
+        scripts: {echo: 'echo'},
+      }),
+    );
+
+    const command = path.resolve(__dirname, '../bin/yarn');
+    const options = {cwd};
+
+    const {stderr: stderr, stdout: stdout} = execa(command, ['run', 'echo', '--opt'], options);
+
+    const stdoutPromise = misc.consumeStream(stdout);
+    const stderrPromise = misc.consumeStream(stderr);
+
+    const [stdoutOutput, stderrOutput] = await Promise.all([stdoutPromise, stderrPromise]);
+
+    expect(stdoutOutput.toString().trim()).toEqual('--opt');
+    expect(stderrOutput.toString()).not.toMatch(/Using -- to pass arguments to your scripts isn't required anymore/);
+  });
+
+  test('yarn run <script> -- --opt', async () => {
+    const cwd = await makeTemp();
+
+    await fs.writeFile(
+      path.join(cwd, 'package.json'),
+      JSON.stringify({
+        scripts: {echo: 'echo'},
+      }),
+    );
+
+    const command = path.resolve(__dirname, '../bin/yarn');
+    const options = {cwd};
+
+    const {stderr: stderr, stdout: stdout} = execa(command, ['run', 'echo', '--', '--opt'], options);
+
+    const stdoutPromise = misc.consumeStream(stdout);
+    const stderrPromise = misc.consumeStream(stderr);
+
+    const [stdoutOutput, stderrOutput] = await Promise.all([stdoutPromise, stderrPromise]);
+
+    expect(stdoutOutput.toString().trim()).toEqual('--opt');
+    expect(stderrOutput.toString()).toMatch(/Using -- to pass arguments to your scripts isn't required anymore/);
+  });
+}
+
 test('cache folder fallback', async () => {
   const cwd = await makeTemp();
   const cacheFolder = path.join(cwd, '.cache');

src/cli/index.js

@@ -114,7 +114,7 @@ export function main({
   // we using "yarn <script> -abc" or "yarn run <script> -abc", we want -abc to be script options, not yarn options
   if (command === commands.run) {
     if (endArgs.length === 0) {
-      endArgs = ['--', ... args.splice(1, args.length)];
+      endArgs = ['--', ...args.splice(1, args.length)];
     } else {
       warnAboutRunDashDash = true;
     }

src/reporters/lang/en.js

@@ -188,7 +188,8 @@ const messages = {
 
   execMissingCommand: 'Missing command name.',
 
-  dashDashDeprecation: "Using -- to pass arguments to your scripts isn't required anymore. Doing this may cause issues in future versions.",
+  dashDashDeprecation:
+    "Using -- to pass arguments to your scripts isn't required anymore. Doing this may cause issues in future versions.",
   commandNotSpecified: 'No command specified.',
   binCommands: 'Commands available from binary scripts: ',
   possibleCommands: 'Project commands',