Add --parallel flag to lerna run

README.md

@@ -442,19 +442,27 @@ List all of the public packages in the current Lerna repo.
 ### run
 
 ```sh
-$ lerna run [script] # runs npm run my-script in all packages that have it
+$ lerna run <script> -- [..args] # runs npm run my-script in all packages that have it
 $ lerna run test
 $ lerna run build
+
+# watch all packages and transpile on change, streaming prefixed output
+$ lerna run --parallel watch
 ```
 
-Run an [npm script](https://docs.npmjs.com/misc/scripts) in each package that contains that script.
+Run an [npm script](https://docs.npmjs.com/misc/scripts) in each package that contains that script. A double-dash (`--`) is necessary to pass dashed arguments to the script execution.
 
-`lerna run` respects the `--concurrency`, `--scope` and `ignore` flags (see [Flags](#flags)).
+`lerna run` respects the `--concurrency`, `--scope`, `--ignore`, `--stream`, and `--parallel` flags (see [Flags](#flags)).
 
 ```sh
 $ lerna run --scope my-component test
 ```
 
+> Note: It is advised to constrain the scope of this command (and `lerna exec`,
+> below) when using the `--parallel` flag, as spawning dozens of subprocesses
+> may be harmful to your shell's equanimity (or maximum file descriptor limit,
+> for example). YMMV
+
 ### exec
 
 ```sh

src/commands/RunCommand.js

@@ -1,3 +1,5 @@
+import async from "async";
+
 import Command from "../Command";
 import NpmUtilities from "../NpmUtilities";
 import output from "../utils/output";
@@ -14,8 +16,14 @@ export const describe = "Run an npm script in each package that contains that sc
 export const builder = {
   "stream": {
     group: "Command Options:",
-    describe: "Stream output with lines prefixed by package."
-  }
+    describe: "Stream output with lines prefixed by package.",
+    type: "boolean",
+  },
+  "parallel": {
+    group: "Command Options:",
+    describe: "Run script in all packages with unlimited concurrency, streaming prefixed output",
+    type: "boolean",
+  },
 };
 
 export default class RunCommand extends Command {
@@ -40,6 +48,11 @@ export default class RunCommand extends Command {
       return;
     }
 
+    if (this.options.parallel || this.options.stream) {
+      // don't interrupt streaming stdio
+      this.logger.disableProgress();
+    }
+
     this.batchedPackages = this.toposort
       ? PackageUtilities.topologicallyBatchPackages(this.packagesWithScript)
       : [this.packagesWithScript];
@@ -48,18 +61,24 @@ export default class RunCommand extends Command {
   }
 
   execute(callback) {
-    this.runScriptInPackages((err) => {
+    const finish = (err) => {
       if (err) {
         callback(err);
       } else {
         this.logger.success("run", `Ran npm script '${this.script}' in packages:`);
         this.logger.success("", this.packagesWithScript.map((pkg) => `- ${pkg.name}`).join("\n"));
         callback(null, true);
       }
-    });
+    };
+
+    if (this.options.parallel) {
+      this.runScriptInPackagesParallel(finish);
+    } else {
+      this.runScriptInPackagesBatched(finish);
+    }
   }
 
-  runScriptInPackages(callback) {
+  runScriptInPackagesBatched(callback) {
     PackageUtilities.runParallelBatches(this.batchedPackages, (pkg) => (done) => {
       this.runScriptInPackage(pkg, done);
     }, this.concurrency, callback);
@@ -73,6 +92,19 @@ export default class RunCommand extends Command {
     }
   }
 
+  runScriptInPackagesParallel(callback) {
+    this.logger.info(
+      "run",
+      "in %d package(s): npm run %s",
+      this.packagesWithScript.length,
+      [this.script].concat(this.args).join(" ")
+    );
+
+    async.parallel(this.packagesWithScript.map((pkg) => (done) => {
+      this.runScriptInPackageStreaming(pkg, done);
+    }), callback);
+  }
+
   runScriptInPackageStreaming(pkg, callback) {
     NpmUtilities.runScriptInPackageStreaming(this.script, this.args, pkg, callback);
   }

test/RunCommand.js

@@ -146,6 +146,28 @@ describe("RunCommand", () => {
         }));
       });
     });
+
+    it("runs a script in all packages with --parallel", (done) => {
+      const runCommand = new RunCommand(["env"], {
+        parallel: true,
+      }, testDir);
+
+      runCommand.runValidations();
+      runCommand.runPreparations();
+
+      runCommand.runCommand(exitWithCode(0, (err) => {
+        if (err) return done.fail(err);
+
+        try {
+          expect(ranInPackagesStreaming(testDir))
+            .toMatchSnapshot("run <script> --parallel");
+
+          done();
+        } catch (ex) {
+          done.fail(ex);
+        }
+      }));
+    });
   });
 
   describe("with --include-filtered-dependencies", () => {

test/__snapshots__/RunCommand.js.snap

@@ -6,6 +6,15 @@ Array [
 ]
 `;
 
+exports[`run <script> --parallel 1`] = `
+Array [
+  "packages/package-1 env",
+  "packages/package-2 env",
+  "packages/package-3 env",
+  "packages/package-4 env",
+]
+`;
+
 exports[`run <script> --scope @test/package-2 --include-filtered-dependencies 1`] = `
 Array [
   "packages/package-1 my-script",

test/fixtures/RunCommand/integration-lifecycle/packages/package-1/package.json

@@ -1,6 +1,9 @@
 {
   "name": "package-1",
   "version": "1.0.0",
+  "devDependencies": {
+    "package-3": "^1.0.0"
+  },
   "scripts": {
     "test": "echo package-1"
   }

test/fixtures/RunCommand/integration-lifecycle/packages/package-2/package.json

@@ -2,6 +2,9 @@
   "name": "package-2",
   "version": "1.0.0",
   "dependencies": {
-    "package-1": "^1.0.0"
+    "package-3": "^1.0.0"
+  },
+  "scripts": {
+    "test": "echo package-2"
   }
 }

test/fixtures/RunCommand/integration-lifecycle/packages/package-3/package.json

@@ -1,7 +1,7 @@
 {
   "name": "package-3",
   "version": "1.0.0",
-  "devDependencies": {
-    "package-2": "^1.0.0"
+  "scripts": {
+    "test": "echo package-3"
   }
 }

test/integration/__snapshots__/lerna-run.test.js.snap

@@ -1,5 +1,13 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
+exports[`stderr: my-script --parallel 1`] = `
+"lerna info version __TEST_VERSION__
+lerna info run in 2 package(s): npm run my-script --silent
+lerna success run Ran npm script 'my-script' in packages:
+lerna success - package-1
+lerna success - package-3"
+`;
+
 exports[`stderr: my-script --scope 1`] = `
 "lerna info version __TEST_VERSION__
 lerna info scope package-1
@@ -14,6 +22,32 @@ lerna success run Ran npm script 'test' in packages:
 lerna success - package-4"
 `;
 
+exports[`stderr: test --parallel 1`] = `
+"lerna info version __TEST_VERSION__
+lerna info run in 4 package(s): npm run test --silent
+lerna success run Ran npm script 'test' in packages:
+lerna success - package-1
+lerna success - package-2
+lerna success - package-3
+lerna success - package-4"
+`;
+
+exports[`stderr: test --stream 1`] = `
+"lerna info version __TEST_VERSION__
+lerna success run Ran npm script 'test' in packages:
+lerna success - package-1
+lerna success - package-2
+lerna success - package-3
+lerna success - package-4"
+`;
+
 exports[`stdout: my-script --scope 1`] = `"package-1"`;
 
 exports[`stdout: test --ignore 1`] = `"package-4"`;
+
+exports[`stdout: test --stream 1`] = `
+"package-3: package-3
+package-4: package-4
+package-1: package-1
+package-2: package-2"
+`;

test/integration/lerna-run.test.js

@@ -3,6 +3,11 @@ import execa from "execa";
 import { LERNA_BIN } from "../helpers/constants";
 import initFixture from "../helpers/initFixture";
 
+/**
+ * NOTE: We do not test the "missing test script" case here
+ * because Windows makes the snapshots impossible to stabilize.
+**/
+
 describe("lerna run", () => {
   test.concurrent("my-script --scope", async () => {
     const cwd = await initFixture("RunCommand/basic");
@@ -34,4 +39,57 @@ describe("lerna run", () => {
     expect(stdout).toMatchSnapshot("stdout: test --ignore");
     expect(stderr).toMatchSnapshot("stderr: test --ignore");
   });
+
+  test.concurrent("test --stream", async () => {
+    const cwd = await initFixture("RunCommand/integration-lifecycle");
+    const args = [
+      "run",
+      "--stream",
+      "test",
+      "--concurrency=1",
+      // args below tell npm to be quiet
+      "--", "--silent",
+    ];
+    const { stdout, stderr } = await execa(LERNA_BIN, args, { cwd });
+    expect(stdout).toMatchSnapshot("stdout: test --stream");
+    expect(stderr).toMatchSnapshot("stderr: test --stream");
+  });
+
+  test.concurrent("test --parallel", async () => {
+    const cwd = await initFixture("RunCommand/integration-lifecycle");
+    const args = [
+      "run",
+      "test",
+      "--parallel",
+      // args below tell npm to be quiet
+      "--", "--silent",
+    ];
+    const { stdout, stderr } = await execa(LERNA_BIN, args, { cwd });
+    expect(stderr).toMatchSnapshot("stderr: test --parallel");
+
+    // order is non-deterministic, so assert each item seperately
+    expect(stdout).toMatch("package-1: package-1");
+    expect(stdout).toMatch("package-2: package-2");
+    expect(stdout).toMatch("package-3: package-3");
+    expect(stdout).toMatch("package-4: package-4");
+  });
+
+  test.concurrent("my-script --parallel", async () => {
+    const cwd = await initFixture("RunCommand/basic");
+    const args = [
+      "run",
+      "--parallel",
+      "my-script",
+      // args below tell npm to be quiet
+      "--", "--silent",
+    ];
+    const { stdout, stderr } = await execa(LERNA_BIN, args, { cwd });
+    expect(stderr).toMatchSnapshot("stderr: my-script --parallel");
+
+    // order is non-deterministic, so assert each item seperately
+    expect(stdout).toMatch("package-1: package-1");
+    expect(stdout).not.toMatch("package-2");
+    expect(stdout).toMatch("package-3: package-3");
+    expect(stdout).not.toMatch("package-4");
+  });
 });