Replace vendor/constants recast transform with babel

Built files look the same up to parenthesization and quoting. This only saves 1.5 seconds out of ~20 on a clean build but it's a little simpler.
hakunin · May 5, 2015 · ceb92cd · ceb92cd
1 parent aee3614
commit ceb92cd
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Showing 4 changed files with 51 additions and 87 deletions.
diff --git a/bin/jsx-internal b/bin/jsx-internal
@@ -5,7 +5,7 @@
 
 var babel = require('babel-core');
 
-var propagate = require("../vendor/constants").propagate;
+var constants = require('../vendor/constants')(babel);
 
 require("commoner").version(
   require("../package.json").version
@@ -29,18 +29,14 @@ require("commoner").version(
 
 }).process(function(id, source) {
   var context = this;
-  var constants = context.config.constants || {};
 
   // This is where JSX, ES6, etc. desugaring happens.
   source = babel.transform(source, {
     blacklist: ['spec.functionName', 'validation.react'],
+    plugins: [constants],
     filename: id
   }).code;
 
-  // Constant propagation means removing any obviously dead code after
-  // replacing constant expressions with literal (boolean) values.
-  source = propagate(constants, source);
-
   if (context.config.mocking) {
     // Make sure there is exactly one newline at the end of the module.
     source = source.replace(/\s+$/m, "\n");

diff --git a/grunt/config/jsx.js b/grunt/config/jsx.js
@@ -12,8 +12,7 @@ var normal = {
   rootIDs: rootIDs,
   getConfig: function() {
     return {
-      commonerConfig: grunt.config.data.pkg.commonerConfig,
-      constants: {}
+      commonerConfig: grunt.config.data.pkg.commonerConfig
     };
   },
   sourceDir: 'src',

diff --git a/package.json b/package.json
@@ -57,7 +57,6 @@
     "phantomjs": "~1.9",
     "platform": "^1.1.0",
     "populist": "~0.1.6",
-    "recast": "^0.9.11",
     "sauce-tunnel": "~1.1.0",
     "tmp": "~0.0.18",
     "typescript": "^1.4.0",
@@ -70,7 +69,7 @@
   },
   "preferGlobal": true,
   "commonerConfig": {
-    "version": 5
+    "version": 6
   },
   "scripts": {
     "test": "jest",

diff --git a/vendor/constants.js b/vendor/constants.js
@@ -8,83 +8,53 @@
  */
 'use strict';
 
-var recast = require('recast');
-var types = recast.types;
-var builders = types.builders;
-
-function propagate(constants, source) {
-  return recast.print(transform(recast.parse(source), constants)).code;
-}
-
-var DEV_EXPRESSION = builders.binaryExpression(
-  '!==',
-  builders.literal('production'),
-  builders.memberExpression(
-    builders.memberExpression(
-      builders.identifier('process'),
-      builders.identifier('env'),
+module.exports = function(babel) {
+  var t = babel.types;
+
+  var DEV_EXPRESSION = t.binaryExpression(
+    '!==',
+    t.literal('production'),
+    t.memberExpression(
+      t.memberExpression(
+        t.identifier('process'),
+        t.identifier('env'),
+        false
+      ),
+      t.identifier('NODE_ENV'),
       false
-    ),
-    builders.identifier('NODE_ENV'),
-    false
-  )
-);
-
-var visitors = {
-  visitIdentifier: function(nodePath) {
-    // If the identifier is the property of a member expression
-    // (e.g. object.property), then it definitely is not a constant
-    // expression that we want to replace.
-    if (nodePath.parentPath.value.type === 'MemberExpression') {
-      return false;
-    }
-
-    // replace __DEV__ with process.env.NODE_ENV !== 'production'
-    if (nodePath.value.name === '__DEV__') {
-      nodePath.replace(DEV_EXPRESSION);
+    )
+  );
+
+  return new babel.Transformer('react.constants', {
+    Identifier: {
+      enter: function(node, parent) {
+        // replace __DEV__ with process.env.NODE_ENV !== 'production'
+        if (this.isIdentifier({name: '__DEV__'})) {
+          return DEV_EXPRESSION;
+        }
+      }
+    },
+    CallExpression: {
+      exit: function(node, parent) {
+        if (this.get('callee').isIdentifier({name: 'invariant'})) {
+          // Truncate the arguments of invariant(condition, ...)
+          // statements to just the condition based on NODE_ENV
+          // (dead code removal will remove the extra bytes).
+          return t.conditionalExpression(
+            DEV_EXPRESSION,
+            node,
+            t.callExpression(node.callee, [node.arguments[0]])
+          );
+        } else if (this.get('callee').isIdentifier({name: 'warning'})) {
+          // Eliminate warning(condition, ...) statements based on NODE_ENV
+          // (dead code removal will remove the extra bytes).
+          return t.conditionalExpression(
+            DEV_EXPRESSION,
+            node,
+            t.literal(null)
+          );
+        }
+      }
     }
-    // TODO: bring back constant replacement if we decide we need it
-
-    this.traverse(nodePath);
-  },
-
-  visitCallExpression: function(nodePath) {
-    var node = nodePath.value;
-    if (node.callee.name === 'invariant') {
-      // Truncate the arguments of invariant(condition, ...)
-      // statements to just the condition based on NODE_ENV
-      // (dead code removal will remove the extra bytes).
-      nodePath.replace(
-        builders.conditionalExpression(
-          DEV_EXPRESSION,
-          node,
-          builders.callExpression(
-            node.callee,
-            [node.arguments[0]]
-          )
-        )
-      );
-      return false;
-    } else if (node.callee.name === 'warning') {
-      // Eliminate warning(condition, ...) statements based on NODE_ENV
-      // (dead code removal will remove the extra bytes).
-      nodePath.replace(
-        builders.conditionalExpression(
-          DEV_EXPRESSION,
-          node,
-          builders.literal(null)
-        )
-      );
-      return false;
-    }
-    this.traverse(nodePath);
-  }
+  });
 };
-
-function transform(ast, constants) {
-  // TODO constants
-  return recast.visit(ast, visitors);
-}
-
-exports.propagate = propagate;
-exports.transform = transform;