fix: set side effects to false (#122)

Author: evilebottnawi

package-lock.json

@@ -67,8 +67,10 @@
     "memfs": "^3.2.0",
     "npm-run-all": "^4.1.5",
     "prettier": "^2.2.0",
+    "react": "^17.0.1",
     "rx": "^4.1.0",
     "standard-version": "^9.0.0",
+    "styled-components": "^5.2.1",
     "webpack": "^5.6.0"
   },
   "keywords": [

package.json

@@ -24,15 +24,6 @@ export default function loader() {
     baseDataPath: "options",
   });
 
-  /*
-   * Workaround until module.libIdent() in webpack/webpack handles this correctly.
-   *
-   * Fixes:
-   * - https://github.com/webpack-contrib/expose-loader/issues/55
-   * - https://github.com/webpack-contrib/expose-loader/issues/49
-   */
-  this._module.userRequest = getNewUserRequest(this._module.userRequest);
-
   const callback = this.async();
 
   let exposes;
@@ -45,6 +36,25 @@ export default function loader() {
     return;
   }
 
+  /*
+   * Workaround until module.libIdent() in webpack/webpack handles this correctly.
+   *
+   * Fixes:
+   * - https://github.com/webpack-contrib/expose-loader/issues/55
+   * - https://github.com/webpack-contrib/expose-loader/issues/49
+   */
+  this._module.userRequest = getNewUserRequest(this._module.userRequest);
+
+  /*
+   * Adding side effects
+   *
+   * Fixes:
+   * - https://github.com/webpack-contrib/expose-loader/issues/120
+   */
+  if (this._module.factoryMeta) {
+    this._module.factoryMeta.sideEffectFree = false;
+  }
+
   // Change the request from an /abolute/path.js to a relative ./path.js.
   // This prevents [chunkhash] values from changing when running webpack builds in different directories.
   const newRequest = contextify(this.context, getRemainingRequest(this));

src/index.js

@@ -1006,6 +1006,92 @@ Object {
 
 exports[`loader should work with multiple exposes: warnings 1`] = `Array []`;
 
+exports[`loader should work with side-effects free modules #1: errors 1`] = `Array []`;
+
+exports[`loader should work with side-effects free modules #1: result 1`] = `
+Object {
+  "ExposeLoader": Object {
+    "default": Object {
+      "ServerStyleSheet": [Function],
+      "StyleSheetConsumer": Object {
+        "$$typeof": Symbol(react.context),
+        "Consumer": [Circular],
+        "Provider": Object {
+          "$$typeof": Symbol(react.provider),
+          "_context": [Circular],
+        },
+        "_calculateChangedBits": null,
+        "_currentValue": undefined,
+        "_currentValue2": undefined,
+        "_threadCount": 0,
+      },
+      "StyleSheetContext": Object {
+        "$$typeof": Symbol(react.context),
+        "Consumer": [Circular],
+        "Provider": Object {
+          "$$typeof": Symbol(react.provider),
+          "_context": [Circular],
+        },
+        "_calculateChangedBits": null,
+        "_currentValue": undefined,
+        "_currentValue2": undefined,
+        "_threadCount": 0,
+      },
+      "StyleSheetManager": [Function],
+      "ThemeConsumer": Object {
+        "$$typeof": Symbol(react.context),
+        "Consumer": [Circular],
+        "Provider": Object {
+          "$$typeof": Symbol(react.provider),
+          "_context": [Circular],
+        },
+        "_calculateChangedBits": null,
+        "_currentValue": undefined,
+        "_currentValue2": undefined,
+        "_threadCount": 0,
+      },
+      "ThemeContext": Object {
+        "$$typeof": Symbol(react.context),
+        "Consumer": [Circular],
+        "Provider": Object {
+          "$$typeof": Symbol(react.provider),
+          "_context": [Circular],
+        },
+        "_calculateChangedBits": null,
+        "_currentValue": undefined,
+        "_currentValue2": undefined,
+        "_threadCount": 0,
+      },
+      "ThemeProvider": [Function],
+      "__PRIVATE__": Object {
+        "StyleSheet": [Function],
+        "masterSheet": e {
+          "gs": Object {},
+          "names": Map {},
+          "options": Object {
+            "isServer": true,
+            "useCSSOMInjection": true,
+          },
+        },
+      },
+      "createGlobalStyle": [Function],
+      "css": [Function],
+      "default": [Function],
+      "isStyledComponent": [Function],
+      "keyframes": [Function],
+      "useTheme": [Function],
+      "version": "5.2.1",
+      "withTheme": [Function],
+    },
+  },
+  "global-commonjs2-single-export": Object {
+    "foo": "bar",
+  },
+}
+`;
+
+exports[`loader should work with side-effects free modules #1: warnings 1`] = `Array []`;
+
 exports[`loader should work with side-effects free modules: errors 1`] = `Array []`;
 
 exports[`loader should work with side-effects free modules: module 1`] = `

test/__snapshots__/loader.test.js.snap

@@ -0,0 +1,6 @@
+import "styled-components";
+import myGlobalThis from '../../src/runtime/getGlobalThis';
+
+const exported = myGlobalThis.styled;
+
+export default exported;

test/fixtures/side-effects-1.js

@@ -15,6 +15,7 @@ export default (code) => {
   // eslint-disable-next-line no-underscore-dangle
   module._compile(
     `
+window = {};
 console.log = () => {};
 
 const result = {};

test/helpers/execute.js

@@ -19,7 +19,7 @@ export default (fixture, loaderOptions = {}, config = {}) => {
     module: {
       rules: [
         {
-          test: /(global-.+|rx\.all)\.js/i,
+          test: /(global-.+|rx\.all|styled-components.+)\.js/i,
           rules: [
             {
               loader: path.resolve(__dirname, "../../src"),

test/helpers/getCompiler.js

@@ -736,6 +736,25 @@ describe("loader", () => {
     expect(getWarnings(stats)).toMatchSnapshot("warnings");
   });
 
+  it("should work with side-effects free modules #1", async () => {
+    const compiler = getCompiler(
+      "side-effects-1.js",
+      {
+        exposes: "styled",
+      },
+      {
+        mode: "production",
+      }
+    );
+    const stats = await compile(compiler);
+
+    expect(
+      execute(readAsset("main.bundle.js", compiler, stats))
+    ).toMatchSnapshot("result");
+    expect(getErrors(stats)).toMatchSnapshot("errors");
+    expect(getWarnings(stats)).toMatchSnapshot("warnings");
+  });
+
   it("should throw an error on invalid exposed value", async () => {
     const compiler = getCompiler("simple-commonjs2-single-export.js", {
       exposes: "myGlobal foo bar baz",