Merged in wbinnssmith/tree-shake (pull request #34)

Restore tree shaking Approved-by: Maia Teegarden
parcel-bundler · Apr 14, 2020 · 4accd9e · 4accd9e
2 parents 1f33b21 + 19535ed
commit 4accd9e
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Showing 12 changed files with 133 additions and 58 deletions.
diff --git a/packages/core/integration-tests/test/integration/less-url-behavior/index.less b/packages/core/integration-tests/test/integration/less-url-behavior/index.less
@@ -0,0 +1,3 @@
+.index {
+  behavior: url(#default#VML);
+}
diff --git a/...ation-tests/test/integration/scope-hoisting/commonjs/tree-shaking-no-unknown-objects/a.js b/...ation-tests/test/integration/scope-hoisting/commonjs/tree-shaking-no-unknown-objects/a.js
@@ -0,0 +1 @@
+module.exports = window;
diff --git a/...n-tests/test/integration/scope-hoisting/commonjs/tree-shaking-no-unknown-objects/index.js b/...n-tests/test/integration/scope-hoisting/commonjs/tree-shaking-no-unknown-objects/index.js
@@ -0,0 +1,3 @@
+const foo = require('./a');
+foo.bar = 42;
+output = window.bar;
diff --git a/...ntegration-tests/test/integration/scope-hoisting/es6/tree-shaking-no-unknown-objects/a.js b/...ntegration-tests/test/integration/scope-hoisting/es6/tree-shaking-no-unknown-objects/a.js
@@ -0,0 +1 @@
+export const foo = window;
diff --git a/...ration-tests/test/integration/scope-hoisting/es6/tree-shaking-no-unknown-objects/index.js b/...ration-tests/test/integration/scope-hoisting/es6/tree-shaking-no-unknown-objects/index.js
@@ -0,0 +1,5 @@
+import {foo} from './a';
+
+foo.bar = 42;
+
+output = window.bar;
diff --git a/packages/core/integration-tests/test/less.js b/packages/core/integration-tests/test/less.js
@@ -216,4 +216,21 @@ describe('less', function() {
     assert(css.includes('.a'));
     assert(css.includes('.b'));
   });
+
+  it('should ignore url() with IE behavior specifiers', async function() {
+    let b = await bundle(
+      path.join(__dirname, '/integration/less-url-behavior/index.less'),
+    );
+
+    assertBundles(b, [
+      {
+        name: 'index.css',
+        assets: ['index.less'],
+      },
+    ]);
+
+    let css = await outputFS.readFile(path.join(distDir, 'index.css'), 'utf8');
+
+    assert(css.includes('url(#default#VML)'));
+  });
 });
diff --git a/packages/core/integration-tests/test/output-formats.js b/packages/core/integration-tests/test/output-formats.js
@@ -8,8 +8,7 @@ const bundle = (name, opts = {}) =>
 
 describe('output formats', function() {
   describe('commonjs', function() {
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('should support commonjs output (exports)', async function() {
+    it('should support commonjs output (exports)', async function() {
       let b = await bundle(
         path.join(__dirname, '/integration/formats/commonjs/exports.js'),
       );
@@ -21,8 +20,7 @@ describe('output formats', function() {
       assert.equal((await run(b)).bar, 5);
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('should support commonjs output (module.exports)', async function() {
+    it('should support commonjs output (module.exports)', async function() {
       let b = await bundle(
         path.join(__dirname, '/integration/formats/commonjs/module-exports.js'),
       );
@@ -33,8 +31,7 @@ describe('output formats', function() {
       assert.equal(await run(b), 5);
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('should support commonjs output from esmodule input', async function() {
+    it('should support commonjs output from esmodule input', async function() {
       let b = await bundle(
         path.join(__dirname, '/integration/formats/esm-commonjs/a.js'),
       );
@@ -75,8 +72,7 @@ describe('output formats', function() {
       assert.equal((await run(b)).bar, 3);
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('should support commonjs output with external modules (named import)', async function() {
+    it('should support commonjs output with external modules (named import)', async function() {
       let b = await bundle(
         path.join(__dirname, '/integration/formats/commonjs-external/named.js'),
       );
@@ -414,8 +410,7 @@ describe('output formats', function() {
   });
 
   describe('esmodule', function() {
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('should support esmodule output (named export)', async function() {
+    it('should support esmodule output (named export)', async function() {
       let b = await bundle(
         path.join(__dirname, '/integration/formats/esm/named.js'),
       );
@@ -426,8 +421,7 @@ describe('output formats', function() {
       assert(dist.includes('export const bar = foo + 3'));
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('should support esmodule output (default identifier)', async function() {
+    it('should support esmodule output (default identifier)', async function() {
       let b = await bundle(
         path.join(__dirname, '/integration/formats/esm/default-value.js'),
       );
@@ -824,8 +818,7 @@ describe('output formats', function() {
       assert(!async.includes('.css"'));
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('should support building esmodules with split bundles', async function() {
+    it('should support building esmodules with split bundles', async function() {
       let b = await bundle(
         path.join(
           __dirname,

diff --git a/packages/core/integration-tests/test/scope-hoisting.js b/packages/core/integration-tests/test/scope-hoisting.js
@@ -285,7 +285,8 @@ describe('scope hoisting', function() {
       assert.equal(output, 6);
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
+    // ATLASSIAN: Warn and return an empty object expression for unresolvable
+    // imports.
     it.skip('excludes default when re-exporting a module', async function() {
       let threw = false;
       try {
@@ -737,8 +738,7 @@ describe('scope hoisting', function() {
       assert.deepEqual(await run(b), 4);
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('supports importing a namespace from a wrapped module', async function() {
+    it('supports importing a namespace from a wrapped module', async function() {
       let b = await bundle(
         path.join(
           __dirname,
@@ -771,8 +771,7 @@ describe('scope hoisting', function() {
       });
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('removes unused exports', async function() {
+    it('removes unused exports', async function() {
       let b = await bundle(
         path.join(
           __dirname,
@@ -791,8 +790,7 @@ describe('scope hoisting', function() {
       assert(!contents.includes('bar'));
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('removes unused function exports when minified', async function() {
+    it('removes unused function exports when minified', async function() {
       let b = await bundle(
         path.join(
           __dirname,
@@ -812,8 +810,7 @@ describe('scope hoisting', function() {
       assert(!/.-./.test(contents));
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('removes unused transpiled classes using terser when minified', async function() {
+    it('removes unused transpiled classes using terser when minified', async function() {
       let b = await bundle(
         path.join(
           __dirname,
@@ -894,8 +891,7 @@ describe('scope hoisting', function() {
       assert.deepEqual(output, 'bar');
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('should shake pure property assignments', async function() {
+    it('should shake pure property assignments', async function() {
       let b = await bundle(
         path.join(
           __dirname,
@@ -910,8 +906,7 @@ describe('scope hoisting', function() {
         b.getBundles()[0].filePath,
         'utf8',
       );
-      assert(!/bar/.test(contents));
-      assert(!/displayName/.test(contents));
+      assert(!contents.includes('exports.bar ='));
     });
 
     it('should correctly rename references to default exported classes', async function() {
@@ -936,6 +931,17 @@ describe('scope hoisting', function() {
       let output = await run(b);
       assert.deepEqual(output.foo, 'bar');
     });
+
+    it('does not tree-shake assignments to unknown objects', async () => {
+      let b = await bundle(
+        path.join(
+          __dirname,
+          '/integration/scope-hoisting/es6/tree-shaking-no-unknown-objects/index.js',
+        ),
+      );
+
+      assert.equal(await run(b), 42);
+    });
   });
 
   describe('commonjs', function() {
@@ -1467,7 +1473,8 @@ describe('scope hoisting', function() {
       assert.equal(output, 6);
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
+    // ATLASSIAN: Don't inline `require` as `'function'` -- this confuses
+    // browserify-built bundles like Bitbucket connect-js.
     it.skip('supports module object properties', async function() {
       let b = await bundle(
         path.join(
@@ -1734,8 +1741,7 @@ describe('scope hoisting', function() {
       assert.deepEqual(output, {b: {}});
     });
 
-    // ATLASSIAN: Unskip when treeshaking is used again
-    it.skip('removes unused exports', async function() {
+    it('removes unused exports', async function() {
       let b = await bundle(
         path.join(
           __dirname,
@@ -1887,6 +1893,17 @@ describe('scope hoisting', function() {
       let output = await run(b);
       assert.deepEqual(output, [4, 2]);
     });
+
+    it('does not tree-shake assignments to unknown objects', async () => {
+      let b = await bundle(
+        path.join(
+          __dirname,
+          '/integration/scope-hoisting/commonjs/tree-shaking-no-unknown-objects/index.js',
+        ),
+      );
+
+      assert.equal(await run(b), 42);
+    });
   });
 
   it('should not throw with JS included from HTML', async function() {

diff --git a/packages/shared/scope-hoisting/src/link.js b/packages/shared/scope-hoisting/src/link.js
@@ -34,7 +34,7 @@ import {
   isStringLiteral,
 } from '@babel/types';
 import traverse from '@babel/traverse';
-// import treeShake from './shake';
+import treeShake from './shake';
 import {assertString, getName, getIdentifier, verifyScopeState} from './utils';
 import OutputFormats from './formats/index.js';
 
@@ -690,8 +690,6 @@ export function link({
         }
 
         // Generate exports
-        // ATLASSIAN: Disable treeShaking for now. This is used below.
-        // eslint-disable-next-line no-unused-vars
         let exported = format.generateExports(
           bundleGraph,
           bundle,
@@ -701,11 +699,11 @@ export function link({
           options,
         );
 
-        // ATLASSIAN: Disable treeShaking for now.
-        // if (process.env.PARCEL_BUILD_ENV !== 'production') {
-        //   verifyScopeState(path.scope);
-        // }
-        // treeShake(path.scope, exported);
+        if (process.env.PARCEL_BUILD_ENV !== 'production') {
+          verifyScopeState(path.scope);
+        }
+
+        treeShake(path.scope, exported, exportsMap);
       },
     },
   });