From e53f1645c729c3bbcb27ffd41c999ed321f86f9d Mon Sep 17 00:00:00 2001
From: James George <jamesgeorge998001@gmail.com>
Date: Wed, 9 Jun 2021 21:54:06 +0530
Subject: [PATCH] feat(init-generator): add ability to specify a package
 manager of choice (#2769)

* feat: add ability to specify a package manager of choice

* chore: choose default installer based on the lock file presence

* test: update test suite
---
 packages/generators/src/init-generator.ts     | 13 ++++++++--
 .../lib/utils/get-available-installers.js     | 25 +++++++++++++++++++
 packages/webpack-cli/lib/utils/index.js       |  4 +++
 test/init/init.test.js                        | 17 +++++++++----
 4 files changed, 52 insertions(+), 7 deletions(-)
 create mode 100644 packages/webpack-cli/lib/utils/get-available-installers.js

diff --git a/packages/generators/src/init-generator.ts b/packages/generators/src/init-generator.ts
index 1006e2aeb5a..d8868052102 100644
--- a/packages/generators/src/init-generator.ts
+++ b/packages/generators/src/init-generator.ts
@@ -99,8 +99,17 @@ export default class InitGenerator extends CustomGenerator {
         }
     }
 
-    public installPlugins(): void {
-        const packager = this.utils.getPackageManager();
+    public async installPlugins(): Promise<void> {
+        // Prompt for the package manager of choice
+        const defaultPackager = this.utils.getPackageManager();
+        const { packager } = await Question.List(
+            this,
+            "packager",
+            "Pick a package manager:",
+            this.utils.getAvailableInstallers(),
+            defaultPackager,
+            this.force,
+        );
         const opts: {
             dev?: boolean;
             "save-dev"?: boolean;
diff --git a/packages/webpack-cli/lib/utils/get-available-installers.js b/packages/webpack-cli/lib/utils/get-available-installers.js
new file mode 100644
index 00000000000..d2ee92414c5
--- /dev/null
+++ b/packages/webpack-cli/lib/utils/get-available-installers.js
@@ -0,0 +1,25 @@
+const { sync } = require("execa");
+
+const utils = require("./");
+
+function hasPmInstalled(packageManager) {
+    try {
+        sync(packageManager, ["--version"]);
+        return packageManager;
+    } catch (err) {
+        return false;
+    }
+}
+
+function getAvailableInstallers() {
+    const installers = ["npm", "yarn", "pnpm"];
+    const availableInstallers = installers.filter((installer) => hasPmInstalled(installer));
+
+    if (!availableInstallers.length) {
+        utils.logger.error("No package manager found.");
+        process.exit(2);
+    }
+    return availableInstallers;
+}
+
+module.exports = getAvailableInstallers;
diff --git a/packages/webpack-cli/lib/utils/index.js b/packages/webpack-cli/lib/utils/index.js
index 800174bec22..e5ac14c3407 100644
--- a/packages/webpack-cli/lib/utils/index.js
+++ b/packages/webpack-cli/lib/utils/index.js
@@ -23,6 +23,10 @@ module.exports = {
         return require("./dynamic-import-loader");
     },
 
+    get getAvailableInstallers() {
+        return require("./get-available-installers");
+    },
+
     get getPackageManager() {
         return require("./get-package-manager");
     },
diff --git a/test/init/init.test.js b/test/init/init.test.js
index a8ef6cca672..c7221110496 100644
--- a/test/init/init.test.js
+++ b/test/init/init.test.js
@@ -144,7 +144,7 @@ describe("init command", () => {
         const { stdout, stderr } = await runPromptWithAnswers(
             assetsPath,
             ["init"],
-            [`${DOWN}${DOWN}${ENTER}`, `n${ENTER}`, `n${ENTER}`, `n${ENTER}`, ENTER],
+            [`${DOWN}${DOWN}${ENTER}`, `n${ENTER}`, `n${ENTER}`, `n${ENTER}`, ENTER, ENTER],
         );
 
         expect(stdout).toContain("Project has been initialised with webpack!");
@@ -170,7 +170,7 @@ describe("init command", () => {
         const { stdout, stderr } = await runPromptWithAnswers(
             assetsPath,
             ["init"],
-            [`${DOWN}${ENTER}`, `n${ENTER}`, `n${ENTER}`, `n${ENTER}`, ENTER],
+            [`${DOWN}${ENTER}`, `n${ENTER}`, `n${ENTER}`, `n${ENTER}`, ENTER, ENTER],
         );
 
         expect(stdout).toContain("Project has been initialised with webpack!");
@@ -205,6 +205,7 @@ describe("init command", () => {
                 `n${ENTER}`,
                 `n${ENTER}`,
                 `n${ENTER}`,
+                ENTER,
             ],
         );
 
@@ -239,6 +240,7 @@ describe("init command", () => {
                 `n${ENTER}`,
                 `y${ENTER}`,
                 `n${ENTER}`,
+                ENTER,
             ],
         );
 
@@ -279,6 +281,7 @@ describe("init command", () => {
                 `n${ENTER}`,
                 `n${ENTER}`,
                 `y${ENTER}`,
+                ENTER,
             ],
         );
 
@@ -313,6 +316,7 @@ describe("init command", () => {
                 `y${ENTER}`,
                 `y${ENTER}`,
                 `n${ENTER}`,
+                ENTER,
             ],
         );
 
@@ -353,6 +357,7 @@ describe("init command", () => {
                 `n${ENTER}`,
                 `n${ENTER}`,
                 `n${ENTER}`,
+                ENTER,
             ],
         );
 
@@ -387,6 +392,7 @@ describe("init command", () => {
                 `n${ENTER}`,
                 `n${ENTER}`,
                 `n${ENTER}`,
+                ENTER,
             ],
         );
 
@@ -412,7 +418,7 @@ describe("init command", () => {
         const { stdout, stderr } = await runPromptWithAnswers(
             assetsPath,
             ["init"],
-            [ENTER, ENTER, `n${ENTER}`, `n${ENTER}`, ENTER],
+            [ENTER, ENTER, `n${ENTER}`, `n${ENTER}`, ENTER, ENTER],
         );
 
         expect(stdout).toContain("Do you want to use webpack-dev-server?");
@@ -445,6 +451,7 @@ describe("init command", () => {
                 `${DOWN}${ENTER}`,
                 ENTER,
                 `n${ENTER}`,
+                ENTER,
             ],
         );
 
@@ -476,7 +483,7 @@ describe("init command", () => {
         const { stdout, stderr } = await runPromptWithAnswers(
             assetsPath,
             ["init"],
-            [ENTER, `n${ENTER}`, ENTER, `n${ENTER}`, ENTER],
+            [ENTER, `n${ENTER}`, ENTER, `n${ENTER}`, ENTER, ENTER],
         );
 
         expect(stdout).toContain(
@@ -504,7 +511,7 @@ describe("init command", () => {
         const { stdout, stderr } = await runPromptWithAnswers(
             assetsPath,
             ["init"],
-            [ENTER, `n${ENTER}`, ENTER, ENTER, ENTER],
+            [ENTER, `n${ENTER}`, ENTER, ENTER, ENTER, ENTER],
         );
 
         expect(stdout).toContain("Do you want to add PWA support?");