fix: defer setting default mode to core (#2095)

Author: anshumanv

packages/webpack-cli/lib/webpack-cli.js

@@ -112,8 +112,6 @@ class WebpackCLI {
                 finalMode = configMode;
             } else if (NODE_ENV && (NODE_ENV === PRODUCTION || NODE_ENV === DEVELOPMENT)) {
                 finalMode = NODE_ENV;
-            } else {
-                finalMode = PRODUCTION;
             }
 
             return finalMode;
@@ -208,10 +206,16 @@ class WebpackCLI {
             // Todo - handle multi config for all flags
             finalOptions.options = configOptions.map(() => ({ ...finalOptions.options }));
             configOptions.forEach((configObject, index) => {
-                finalOptions.options[index].mode = assignMode(mode, configObject);
+                const resolvedMode = assignMode(mode, configObject);
+                if (resolvedMode) {
+                    finalOptions.options[index].mode = resolvedMode;
+                }
             });
         } else {
-            finalOptions.options.mode = assignMode(mode, configOptions);
+            const resolvedMode = assignMode(mode, configOptions);
+            if (resolvedMode) {
+                finalOptions.options.mode = resolvedMode;
+            }
         }
 
         return finalOptions;

test/build-warnings/warnings.test.js

@@ -21,7 +21,7 @@ describe('warnings', () => {
         const json = JSON.parse(stdout);
 
         expect(json['hash']).toBeDefined();
-        expect(json['warnings']).toHaveLength(1);
+        expect(json['warnings']).toHaveLength(2);
         // `message` for `webpack@5`
         expect(json['warnings'][0].message ? json['warnings'][0].message : json['warnings'][0]).toMatch(/Can't resolve/);
     });
@@ -43,7 +43,7 @@ describe('warnings', () => {
                 const json = JSON.parse(data);
 
                 expect(json['hash']).toBeDefined();
-                expect(json['warnings']).toHaveLength(1);
+                expect(json['warnings']).toHaveLength(2);
                 // `message` for `webpack@5`
                 expect(json['warnings'][0].message ? json['warnings'][0].message : json['warnings'][0]).toMatch(/Can't resolve/);
 

test/colors/colors-false.webpack.config.js

@@ -2,4 +2,5 @@ module.exports = {
     stats: {
         colors: false,
     },
+    mode: 'production',
 };

test/colors/colors-true.webpack.config.js

@@ -2,4 +2,5 @@ module.exports = {
     stats: {
         colors: true,
     },
+    mode: 'production',
 };

test/colors/multiple-configs.js

@@ -3,10 +3,12 @@ module.exports = [
         name: 'first-config',
         entry: './src/first.js',
         stats: 'normal',
+        mode: 'production',
     },
     {
         name: 'second-config',
         entry: './src/second.js',
         stats: 'normal',
+        mode: 'production',
     },
 ];

test/colors/no-stats.webpack.config.js

@@ -1,3 +1,4 @@
 module.exports = {
     name: 'test',
+    mode: 'production',
 };

test/colors/stats-boolean.webpack.config.js

@@ -1,3 +1,4 @@
 module.exports = {
     stats: true,
+    mode: 'production',
 };

test/colors/stats-string.webpack.config.js

@@ -1,3 +1,4 @@
 module.exports = {
     stats: 'verbose',
+    mode: 'production',
 };

test/colors/webpack.config.js

@@ -0,0 +1,3 @@
+module.exports = {
+    mode: 'production',
+};

test/defaults/output-defaults.test.js

@@ -9,8 +9,8 @@ describe('output flag defaults', () => {
 
         expect(stderr).toBeFalsy();
         expect(exitCode).toBe(0);
-        // Should not print warning about config fallback, as we have production as default
-        expect(stdout).not.toContain('option has not been set, webpack will fallback to');
+        // Should print warning about config fallback
+        expect(stdout).toContain('option has not been set, webpack will fallback to');
         stat(resolve(__dirname, './binary/main.js'), (err, stats) => {
             expect(err).toBe(null);
             expect(stats.isFile()).toBe(true);

test/merge/config/merge-config.test.js

@@ -8,7 +8,7 @@ const { run } = require('../../utils/test-utils');
 describe('merge flag configuration', () => {
     it('merges two configurations together', () => {
         const { stdout, stderr, exitCode } = run(__dirname, ['--config', './1.js', '-c', './2.js', '--merge'], false);
-        expect(stdout).not.toContain('option has not been set, webpack will fallback to');
+        expect(stdout).toContain('option has not been set, webpack will fallback to');
         expect(existsSync(resolve(__dirname, './dist/merged.js'))).toBeTruthy();
         expect(stderr).toBeFalsy();
         expect(exitCode).toBe(0);

test/mode/mode-single-arg/mode-single-arg.test.js

@@ -2,12 +2,13 @@
 const { run } = require('../../utils/test-utils');
 
 describe('mode flags', () => {
-    it('should set mode=production by default', () => {
+    it('should not set mode=production by default', () => {
         const { stderr, stdout, exitCode } = run(__dirname);
 
         expect(exitCode).toBe(0);
         expect(stderr).toBeFalsy();
-        expect(stdout).toContain(`mode: 'production'`);
+        expect(stdout).not.toContain(`mode: 'production'`);
+        expect(stdout).toContain(`The 'mode' option has not been set, webpack will fallback to 'production' for this value.`);
     });
 
     it('should load a development config when --mode=development is passed', () => {

test/stats/watch/webpack.config.js

@@ -1,4 +1,5 @@
 module.exports = {
     watch: true,
     stats: 'none',
+    mode: 'production',
 };

test/watch/watch-flag.test.js

@@ -10,7 +10,7 @@ const wordsInStatsv5 = ['asset', 'index.js', 'compiled successfully'];
 
 describe('--watch flag', () => {
     it('should recompile upon file change', (done) => {
-        const proc = runAndGetWatchProc(__dirname, ['--watch'], false, '', true);
+        const proc = runAndGetWatchProc(__dirname, ['--watch', '--mode', 'production'], false, '', true);
         let semaphore = 0;
         proc.stdout.on('data', (chunk) => {
             const data = stripAnsi(chunk.toString());
@@ -45,7 +45,7 @@ describe('--watch flag', () => {
     });
 
     it('should print compilation lifecycle', (done) => {
-        const proc = runAndGetWatchProc(__dirname, ['--watch'], false, '', true);
+        const proc = runAndGetWatchProc(__dirname, ['--watch', '--mode', 'production'], false, '', true);
         let semaphore = 0;
         proc.stdout.on('data', (chunk) => {
             const data = stripAnsi(chunk.toString());