Make constant folding plugin use context for babel types

Summary: This makes the plugin use the passed on babel api rather than hardcoded pulling in babel 6 or 7. This is important since they are different packages now and we need to work with them side-by-side.

Reviewed By: mjesun

Differential Revision: D7083873

fbshipit-source-id: 2ce89e0627005bb29ff8d3e0e1ac51fe8ee4eabd

packages/metro/src/JSTransformer/worker/__tests__/constant-folding-plugin-test.js

@@ -10,12 +10,29 @@
  */
 'use strict';
 
-const constantFolding = require('../constant-folding');
+const constantFoldingPlugin = require('../constant-folding-plugin');
 
 const {transformSync} = require('../../../babel-bridge');
+const {transformFromAstSync} = require('../../../babel-bridge');
 
 import type {TransformResult} from '@babel/core';
 
+function constantFolding(
+  filename: string,
+  transformResult: TransformResult,
+): TransformResult {
+  return transformFromAstSync(transformResult.ast, transformResult.code, {
+    filename,
+    plugins: [constantFoldingPlugin],
+    inputSourceMap: transformResult.map || undefined, // may not be null
+    sourceMaps: true,
+    sourceFileName: filename,
+    babelrc: false,
+    compact: true,
+    retainLines: true,
+  });
+}
+
 function parse(code: string): TransformResult {
   return transformSync(code, {
     code: false,

packages/metro/src/JSTransformer/worker/__tests__/worker-test.js

@@ -10,7 +10,7 @@
 'use strict';
 
 jest
-  .mock('../constant-folding')
+  .mock('../constant-folding-plugin')
   .mock('../inline-plugin')
   .mock('metro-minify-uglify');
 

packages/metro/src/JSTransformer/worker/constant-folding-plugin.js

@@ -0,0 +1,73 @@
+/**
+ * Copyright (c) 2016-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
+ */
+
+'use strict';
+
+import typeof {types as BabelTypes} from 'babel-core';
+
+function constantFoldingPlugin(context: {types: BabelTypes}) {
+  const t = context.types;
+
+  const Conditional = {
+    exit(path: Object) {
+      const node = path.node;
+      const test = node.test;
+      if (t.isLiteral(test)) {
+        if (test.value || node.alternate) {
+          path.replaceWith(test.value ? node.consequent : node.alternate);
+        } else if (!test.value) {
+          path.remove();
+        }
+      }
+    },
+  };
+
+  return {
+    visitor: {
+      BinaryExpression: {
+        exit(path: Object) {
+          const node = path.node;
+          if (t.isLiteral(node.left) && t.isLiteral(node.right)) {
+            const result = path.evaluate();
+            if (result.confident) {
+              path.replaceWith(t.valueToNode(result.value));
+            }
+          }
+        },
+      },
+      ConditionalExpression: Conditional,
+      IfStatement: Conditional,
+      LogicalExpression: {
+        exit(path: Object) {
+          const node = path.node;
+          const left = node.left;
+          if (t.isLiteral(left)) {
+            const value = t.isNullLiteral(left) ? null : left.value;
+            if (node.operator === '||') {
+              path.replaceWith(value ? left : node.right);
+            } else {
+              path.replaceWith(value ? node.right : left);
+            }
+          }
+        },
+      },
+      UnaryExpression: {
+        exit(path: Object) {
+          const node = path.node;
+          if (node.operator === '!' && t.isLiteral(node.argument)) {
+            path.replaceWith(t.valueToNode(!node.argument.value));
+          }
+        },
+      },
+    },
+  };
+}
+
+module.exports = constantFoldingPlugin;

packages/metro/src/JSTransformer/worker/constant-folding.js

@@ -1,86 +0,0 @@
-/**
- * Copyright (c) 2016-present, Facebook, Inc.
- *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
- *
- * @flow
- * @format
- */
-
-'use strict';
-
-const {babelTypes: t} = require('../../babel-bridge');
-const {transformFromAstSync} = require('../../babel-bridge');
-
-import type {TransformResult} from '@babel/core';
-
-const Conditional = {
-  exit(path) {
-    const node = path.node;
-    const test = node.test;
-    if (t.isLiteral(test)) {
-      if (test.value || node.alternate) {
-        path.replaceWith(test.value ? node.consequent : node.alternate);
-      } else if (!test.value) {
-        path.remove();
-      }
-    }
-  },
-};
-
-const plugin = {
-  visitor: {
-    BinaryExpression: {
-      exit(path) {
-        const node = path.node;
-        if (t.isLiteral(node.left) && t.isLiteral(node.right)) {
-          const result = path.evaluate();
-          if (result.confident) {
-            path.replaceWith(t.valueToNode(result.value));
-          }
-        }
-      },
-    },
-    ConditionalExpression: Conditional,
-    IfStatement: Conditional,
-    LogicalExpression: {
-      exit(path) {
-        const node = path.node;
-        const left = node.left;
-        if (t.isLiteral(left)) {
-          const value = t.isNullLiteral(left) ? null : left.value;
-          if (node.operator === '||') {
-            path.replaceWith(value ? left : node.right);
-          } else {
-            path.replaceWith(value ? node.right : left);
-          }
-        }
-      },
-    },
-    UnaryExpression: {
-      exit(path) {
-        const node = path.node;
-        if (node.operator === '!' && t.isLiteral(node.argument)) {
-          path.replaceWith(t.valueToNode(!node.argument.value));
-        }
-      },
-    },
-  },
-};
-
-function constantFolding(filename: string, transformResult: TransformResult) {
-  return transformFromAstSync(transformResult.ast, transformResult.code, {
-    filename,
-    plugins: [plugin],
-    inputSourceMap: transformResult.map || undefined, // may not be null
-    sourceMaps: true,
-    sourceFileName: filename,
-    babelrc: false,
-    compact: true,
-    retainLines: true,
-  });
-}
-
-constantFolding.plugin = plugin;
-module.exports = constantFolding;

packages/metro/src/JSTransformer/worker/index.js

@@ -14,7 +14,7 @@ const JsFileWrapping = require('../../ModuleGraph/worker/JsFileWrapping');
 
 const assetTransformer = require('../../assetTransformer');
 const collectDependencies = require('../../ModuleGraph/worker/collectDependencies');
-const constantFolding = require('./constant-folding');
+const constantFoldingPlugin = require('./constant-folding-plugin');
 const getMinifier = require('../../lib/getMinifier');
 const inlinePlugin = require('./inline-plugin');
 const optimizeDependencies = require('../../ModuleGraph/worker/optimizeDependencies');
@@ -231,7 +231,7 @@ function transformCode(
 
   const plugins = options.dev
     ? []
-    : [[inlinePlugin, options], [constantFolding.plugin, options]];
+    : [[inlinePlugin, options], [constantFoldingPlugin, options]];
 
   // $FlowFixMe TODO t26372934 Plugin system
   const transformer: Transformer<*> = require(transformerPath);

packages/metro/src/ModuleGraph/worker/optimize-module.js

@@ -10,8 +10,7 @@
 
 'use strict';
 
-const constantFolding = require('../../JSTransformer/worker/constant-folding')
-  .plugin;
+const constantFoldingPlugin = require('../../JSTransformer/worker/constant-folding-plugin');
 const generate = require('./generate');
 const getMinifier = require('../../lib/getMinifier');
 const inlinePlugin = require('../../JSTransformer/worker/inline-plugin');
@@ -117,7 +116,7 @@ function optimizeCode(
 ): BabelTransformResult {
   return transformSync(code, {
     plugins: [
-      [constantFolding],
+      [constantFoldingPlugin],
       [inlinePlugin, {...inliningOptions, isWrapped: true}],
     ],
     babelrc: false,