From 2d1d363b66520820f5734b1df8ac896191b197cd Mon Sep 17 00:00:00 2001
From: Anshuman Verma <anshu.av97@gmail.com>
Date: Tue, 13 Oct 2020 23:11:02 +0530
Subject: [PATCH] feat: allow passing strings in env flag

---
 packages/webpack-cli/lib/groups/ConfigGroup.js       | 10 +---------
 packages/webpack-cli/lib/utils/arg-parser.js         |  9 +++++++++
 packages/webpack-cli/lib/utils/cli-flags.js          |  2 +-
 .../type/function-with-env/function-with-env.test.js |  7 +++++++
 .../type/function-with-env/webpack.env.config.js     | 12 ++++++++++++
 5 files changed, 30 insertions(+), 10 deletions(-)
 create mode 100644 test/config/type/function-with-env/webpack.env.config.js

diff --git a/packages/webpack-cli/lib/groups/ConfigGroup.js b/packages/webpack-cli/lib/groups/ConfigGroup.js
index ae979207d03..80f056101cc 100644
--- a/packages/webpack-cli/lib/groups/ConfigGroup.js
+++ b/packages/webpack-cli/lib/groups/ConfigGroup.js
@@ -153,15 +153,7 @@ const finalize = async (moduleObj, args) => {
     const configOptions = moduleObj.content;
 
     if (typeof configOptions === 'function') {
-        // when config is a function, pass the env from args to the config function
-        let formattedEnv;
-        if (Array.isArray(env)) {
-            formattedEnv = env.reduce((envObject, envOption) => {
-                envObject[envOption] = true;
-                return envObject;
-            }, {});
-        }
-        const newOptions = configOptions(formattedEnv, args);
+        const newOptions = configOptions(env, args);
         // When config function returns a promise, resolve it, if not it's resolved by default
         newOptionsObject['options'] = await Promise.resolve(newOptions);
     } else if (configName) {
diff --git a/packages/webpack-cli/lib/utils/arg-parser.js b/packages/webpack-cli/lib/utils/arg-parser.js
index c72ad1bd7d4..948dbcd656f 100644
--- a/packages/webpack-cli/lib/utils/arg-parser.js
+++ b/packages/webpack-cli/lib/utils/arg-parser.js
@@ -90,6 +90,15 @@ const argParser = (options, args, argsOnly = false, name = '') => {
                 // a multiple argument parsing function
                 const multiArg = (value, previous = []) => previous.concat([value]);
                 parserInstance.option(flagsWithType, option.description, multiArg, option.defaultValue).action(() => {});
+            } else if (option.multipleType) {
+                // for options which accept multiple types like env
+                // so you can do `--env platform=staging --env production`
+                // { platform: "staging", production: true }
+                const multiArg = (value, previous = {}) => {
+                    const [key, val] = value.split('=');
+                    return { ...previous, [key]: val || true };
+                };
+                parserInstance.option(flagsWithType, option.description, multiArg, option.defaultValue).action(() => {});
             } else {
                 // Prevent default behavior for standalone options
                 parserInstance.option(flagsWithType, option.description, option.defaultValue).action(() => {});
diff --git a/packages/webpack-cli/lib/utils/cli-flags.js b/packages/webpack-cli/lib/utils/cli-flags.js
index 0f5f508169a..807d94c0677 100644
--- a/packages/webpack-cli/lib/utils/cli-flags.js
+++ b/packages/webpack-cli/lib/utils/cli-flags.js
@@ -205,7 +205,7 @@ const core = [
         name: 'env',
         usage: '--env',
         type: String,
-        multiple: true,
+        multipleType: true,
         description: 'Environment passed to the configuration when it is a function',
     },
     {
diff --git a/test/config/type/function-with-env/function-with-env.test.js b/test/config/type/function-with-env/function-with-env.test.js
index fae211de366..618f26a4592 100644
--- a/test/config/type/function-with-env/function-with-env.test.js
+++ b/test/config/type/function-with-env/function-with-env.test.js
@@ -18,6 +18,13 @@ describe('function configuration', () => {
         // Should generate the appropriate files
         expect(existsSync(resolve(__dirname, './bin/dev.js'))).toBeTruthy();
     });
+    it('Supports passing string in env', () => {
+        const { stderr, stdout } = run(__dirname, ['--env', 'environment=production', '-c', 'webpack.env.config.js']);
+        expect(stderr).toBeFalsy();
+        expect(stdout).toBeTruthy();
+        // Should generate the appropriate files
+        expect(existsSync(resolve(__dirname, './bin/prod.js'))).toBeTruthy();
+    });
     it('is able to understand multiple env flags', (done) => {
         const { stderr, stdout } = run(__dirname, ['--env', 'isDev', '--env', 'verboseStats', '--env', 'envMessage']);
         expect(stderr).toBeFalsy();
diff --git a/test/config/type/function-with-env/webpack.env.config.js b/test/config/type/function-with-env/webpack.env.config.js
new file mode 100644
index 00000000000..d6c0417a42e
--- /dev/null
+++ b/test/config/type/function-with-env/webpack.env.config.js
@@ -0,0 +1,12 @@
+module.exports = (env) => {
+    const { environment } = env;
+    if (environment === 'production') {
+        return {
+            entry: './a.js',
+            output: {
+                filename: 'prod.js',
+            },
+        };
+    }
+    return {};
+};