make invariant hygienic again

facebook · Jun 3, 2016 · 0a2dacf · 0a2dacf
1 parent a6d4858
commit 0a2dacf
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Showing 3 changed files with 52 additions and 35 deletions.
diff --git a/scripts/error-codes/__tests__/dev-expression-with-codes-test.js b/scripts/error-codes/__tests__/dev-expression-with-codes-test.js
@@ -11,7 +11,6 @@
 
 let babel = require('babel-core');
 let devExpressionWithCodes = require('../dev-expression-with-codes');
-let prodInvariantName = require('../constants').prodInvariantName;
 
 function transform(input) {
   return babel.transform(input, {
@@ -60,39 +59,63 @@ if (process.env.NODE_ENV !== 'production') {
     compare(
 "var invariant = require('invariant');",
 
-`var invariant = require('invariant');
+`var _prodInvariant = require('reactProdInvariant');
 
-var ${prodInvariantName} = require('reactProdInvariant');`
+var invariant = require('invariant');`
     );
   });
 
   it('should replace simple invariant calls', () => {
     compare(
       "invariant(condition, 'Do not override existing functions.');",
+      "var _prodInvariant = require('reactProdInvariant');\n\n" +
+      "!condition ? " +
+      "process.env.NODE_ENV !== 'production' ? " +
+      "invariant(false, 'Do not override existing functions.') : " +
+      `_prodInvariant('16') : void 0;`
+    );
+  });
+
+  it("should only add `reactProdInvariant` once", () => {
+    var expectedInvariantTransformResult = (
       "!condition ? " +
       "process.env.NODE_ENV !== 'production' ? " +
       "invariant(false, 'Do not override existing functions.') : " +
-      `${prodInvariantName}('16') : void 0;`
+      `_prodInvariant('16') : void 0;`
+    );
+
+    compare(
+`var invariant = require('invariant');
+invariant(condition, 'Do not override existing functions.');
+invariant(condition, 'Do not override existing functions.');`,
+
+`var _prodInvariant = require('reactProdInvariant');
+
+var invariant = require('invariant');
+${expectedInvariantTransformResult}
+${expectedInvariantTransformResult}`
     );
   });
 
   it('should support invariant calls with args', () => {
     compare(
       "invariant(condition, 'Expected %s target to be an array; got %s', 'foo', 'bar');",
+      "var _prodInvariant = require('reactProdInvariant');\n\n" +
       "!condition ? " +
       "process.env.NODE_ENV !== 'production' ? " +
       "invariant(false, 'Expected %s target to be an array; got %s', 'foo', 'bar') : " +
-      `${prodInvariantName}('7', 'foo', 'bar') : void 0;`
+      `_prodInvariant('7', 'foo', 'bar') : void 0;`
     );
   });
 
   it('should support invariant calls with a concatenated template string and args', () => {
     compare(
       "invariant(condition, 'Expected a component class, ' + 'got %s.' + '%s', 'Foo', 'Bar');",
+      "var _prodInvariant = require('reactProdInvariant');\n\n" +
       "!condition ? " +
       "process.env.NODE_ENV !== 'production' ? " +
       "invariant(false, 'Expected a component class, got %s.%s', 'Foo', 'Bar') : " +
-      `${prodInvariantName}('18', 'Foo', 'Bar') : void 0;`
+      `_prodInvariant('18', 'Foo', 'Bar') : void 0;`
     );
   });
 

diff --git a/scripts/error-codes/constants.js b/scripts/error-codes/constants.js
diff --git a/scripts/error-codes/dev-expression-with-codes.js b/scripts/error-codes/dev-expression-with-codes.js
@@ -11,22 +11,27 @@
 var evalToString = require('./evalToString');
 var existingErrorMap = require('./codes.json');
 var invertObject = require('./invertObject');
-var prodInvariantName = require('./constants').prodInvariantName;
 
 var errorMap = invertObject(existingErrorMap);
-var prodInvariantModuleName = 'reactProdInvariant';
 
 module.exports = function(babel) {
   var t = babel.types;
 
   var SEEN_SYMBOL = Symbol();
 
-  var buildRequire = babel.template(`var IMPORT_NAME = require(SOURCE);`);
-
-  var REQUIRE_PROD_INVARIANT = buildRequire({
-    IMPORT_NAME: t.identifier(prodInvariantName),
-    SOURCE: t.stringLiteral(prodInvariantModuleName),
-  });
+  function getProdInvariantId(path, localState) {
+    if (!localState.id) {
+      localState.id = path.scope.generateUidIdentifier('prodInvariant');
+      path.scope.getProgramParent().push({
+        id: localState.id,
+        init: t.callExpression(
+          t.identifier('require'),
+          [t.stringLiteral('reactProdInvariant')]
+        ),
+      });
+    }
+    return localState.id;
+  }
 
   var DEV_EXPRESSION = t.binaryExpression(
     '!==',
@@ -43,6 +48,10 @@ module.exports = function(babel) {
   );
 
   return {
+    pre: function() {
+      this.id = null;
+    },
+
     visitor: {
       Identifier: {
         enter: function(path) {
@@ -63,17 +72,16 @@ module.exports = function(babel) {
           if (node[SEEN_SYMBOL]) {
             return;
           }
-          // Insert require('reactProdInvariant') after all `require('invariant')`s.
-          // NOTE currently it only supports the format of
-          // `var invariant = require('invariant');` (VariableDeclaration)
-          // and NOT ES6 imports/assignments.
+          // Insert `var _hygienicVarName = require('reactProdInvariant');`
+          // before all `require('invariant')`s.
+          // NOTE it doesn't support ES6 imports yet.
           if (
             path.get('callee').isIdentifier({name: 'require'}) &&
             path.get('arguments')[0] &&
             path.get('arguments')[0].isStringLiteral({value: 'invariant'})
           ) {
             node[SEEN_SYMBOL] = true;
-            path.parentPath.parentPath.insertAfter(REQUIRE_PROD_INVARIANT);
+            getProdInvariantId(path, this);
           } else if (path.get('callee').isIdentifier({name: 'invariant'})) {
             // Turns this code:
             //
@@ -129,7 +137,8 @@ module.exports = function(babel) {
 
             devInvariant[SEEN_SYMBOL] = true;
 
-            var prodInvariant = t.callExpression(t.identifier(prodInvariantName), [
+            var localInvariantId = getProdInvariantId(path, this);
+            var prodInvariant = t.callExpression(localInvariantId, [
               t.stringLiteral(prodErrorId),
             ].concat(node.arguments.slice(2)));