fix: default context should be undefined instead of null (#965)

Author: manuelbieh

src/utils.js

@@ -120,7 +120,6 @@ function getModulesPlugins(options, loaderContext) {
     mode: 'local',
     localIdentName: '[hash:base64]',
     getLocalIdent,
-    context: null,
     hashPrefix: '',
     localIdentRegExp: null,
   };

test/__snapshots__/modules-option.test.js.snap

@@ -6564,6 +6564,36 @@ Array [
 
 exports[`modules should correctly replace escaped symbols in selector with localIdentName option: warnings 1`] = `Array []`;
 
+exports[`modules should have an undefined context if no context was given: errors 1`] = `Array []`;
+
+exports[`modules should have an undefined context if no context was given: locals 1`] = `
+Object {
+  "abc": "foo",
+  "def": "foo",
+  "ghi": "foo",
+  "jkl": "foo",
+}
+`;
+
+exports[`modules should have an undefined context if no context was given: module (evaluated) 1`] = `
+Array [
+  Array [
+    1,
+    ".foo .foo {
+  color: red;
+}
+
+.foo .foo {
+  color: blue;
+}
+",
+    "",
+  ],
+]
+`;
+
+exports[`modules should have an undefined context if no context was given: warnings 1`] = `Array []`;
+
 exports[`modules should prefixes leading hyphen + digit with underscore with localIdentName option: errors 1`] = `Array []`;
 
 exports[`modules should prefixes leading hyphen + digit with underscore with localIdentName option: locals 1`] = `

test/modules-option.test.js

@@ -288,6 +288,31 @@ describe('modules', () => {
     expect(stats.compilation.errors).toMatchSnapshot('errors');
   });
 
+  it('should have an undefined context if no context was given', async () => {
+    const config = {
+      loader: {
+        options: {
+          modules: {
+            getLocalIdent(loaderContext, localIdentName, localName, options) {
+              expect(options.context).toBeUndefined();
+              return 'foo';
+            },
+          },
+        },
+      },
+    };
+    const testId = './modules/getLocalIdent.css';
+    const stats = await webpack(testId, config);
+    const { modules } = stats.toJson();
+    const module = modules.find((m) => m.id === testId);
+    const evaluatedModule = evaluated(module.source);
+
+    expect(evaluatedModule).toMatchSnapshot('module (evaluated)');
+    expect(evaluatedModule.locals).toMatchSnapshot('locals');
+    expect(stats.compilation.warnings).toMatchSnapshot('warnings');
+    expect(stats.compilation.errors).toMatchSnapshot('errors');
+  });
+
   it('should respects getLocalIdent option (global mode)', async () => {
     const config = {
       loader: {