Merge pull request #6379 from nicolo-ribaudo/helper-runtime-dependencies

Fix helper dependencies in babel runtime

.gitignore

@@ -15,12 +15,16 @@ package-lock.json
 !/packages/babel-runtime/core-js/map.js
 /packages/babel-runtime/helpers/*.js
 !/packages/babel-runtime/helpers/toArray.js
+!/packages/babel-runtime/helpers/temporalRef.js
 /packages/babel-runtime/helpers/builtin/*.js
 !/packages/babel-runtime/helpers/builtin/toArray.js
+!/packages/babel-runtime/helpers/builtin/temporalRef.js
 /packages/babel-runtime/helpers/builtin/es6/*.js
 !/packages/babel-runtime/helpers/builtin/es6/toArray.js
+!/packages/babel-runtime/helpers/builtin/es6/temporalRef.js
 /packages/babel-runtime/helpers/es6/*.js
 !/packages/babel-runtime/helpers/es6/toArray.js
+!/packages/babel-runtime/helpers/es6/temporalRef.js
 /packages/babel-register/test/.babel
 /packages/babel-cli/test/tmp
 /packages/babel-node/test/tmp

packages/babel-core/src/transformation/file/file.js

@@ -1,6 +1,6 @@
 // @flow
 
-import getHelper from "@babel/helpers";
+import * as helpers from "@babel/helpers";
 import { NodePath, Hub, Scope } from "@babel/traverse";
 import { codeFrameColumns } from "@babel/code-frame";
 import traverse from "@babel/traverse";
@@ -132,11 +132,16 @@ export default class File {
       name,
     ));
 
-    const { nodes, globals } = getHelper(
+    const dependencies = {};
+    for (const dep of helpers.getDependencies(name)) {
+      dependencies[dep] = this.addHelper(dep);
+    }
+
+    const { nodes, globals } = helpers.get(
       name,
-      name => this.addHelper(name),
+      dep => dependencies[dep],
       uid,
-      () => Object.keys(this.scope.getAllBindings()),
+      Object.keys(this.scope.getAllBindings()),
     );
 
     globals.forEach(name => {

packages/babel-helpers/src/helpers.js

@@ -600,7 +600,9 @@ helpers.taggedTemplateLiteralLoose = defineHelper(`
 `);
 
 helpers.temporalRef = defineHelper(`
-  export default function _temporalRef(val, name, undef) {
+  import undef from "temporalUndefined";
+
+  export default function _temporalRef(val, name) {
     if (val === undef) {
       throw new ReferenceError(name + " is not defined - temporal dead zone");
     } else {

packages/babel-helpers/src/index.js

@@ -134,8 +134,8 @@ function getHelperMetadata(file) {
 /**
  * Given a helper AST and information about how it will be used, update the AST to match the usage.
  */
-function permuteHelperAST(file, metadata, id, getLocalBindings, getDependency) {
-  if (getLocalBindings && !id) {
+function permuteHelperAST(file, metadata, id, localBindings, getDependency) {
+  if (localBindings && !id) {
     throw new Error("Unexpected local bindings for module-based helpers.");
   }
 
@@ -154,11 +154,11 @@ function permuteHelperAST(file, metadata, id, getLocalBindings, getDependency) {
   const dependenciesRefs = {};
   dependencies.forEach((name, id) => {
     dependenciesRefs[id.name] =
-      typeof getDependency === "function" ? getDependency(name) : id;
+      (typeof getDependency === "function" && getDependency(name)) || id;
   });
 
   const toRename = {};
-  const bindings = new Set((getLocalBindings && getLocalBindings()) || []);
+  const bindings = new Set(localBindings || []);
   localBindingNames.forEach(name => {
     let newName = name;
     while (bindings.has(newName)) newName = "_" + newName;
@@ -237,17 +237,17 @@ function loadHelper(name) {
 
     const metadata = getHelperMetadata(fn());
 
-    // Preload dependencies
-    metadata.dependencies.forEach(loadHelper);
+    helperData[name] = {
+      build(getDependency, id, localBindings) {
+        const file = fn();
+        permuteHelperAST(file, metadata, id, localBindings, getDependency);
 
-    helperData[name] = function(getDependency, id, getLocalBindings) {
-      const file = fn();
-      permuteHelperAST(file, metadata, id, getLocalBindings, getDependency);
-
-      return {
-        nodes: file.program.body,
-        globals: metadata.globals,
-      };
+        return {
+          nodes: file.program.body,
+          globals: metadata.globals,
+        };
+      },
+      dependencies: metadata.dependencies,
     };
   }
 
@@ -256,12 +256,15 @@ function loadHelper(name) {
 
 export function get(
   name,
-  getDependency?: string => t.Expression,
+  getDependency?: string => ?t.Expression,
   id?,
-  getLocalBindings?: () => string[],
+  localBindings?: string[],
 ) {
-  const helper = loadHelper(name);
-  return helper(getDependency, id, getLocalBindings);
+  return loadHelper(name).build(getDependency, id, localBindings);
+}
+
+export function getDependencies(name: string): $ReadOnlyArray<string> {
+  return Array.from(loadHelper(name).dependencies.values());
 }
 
 export const list = Object.keys(helpers)

packages/babel-plugin-transform-es2015-block-scoping/src/tdz.js

@@ -16,7 +16,6 @@ function buildTDZAssert(node, file) {
   return t.callExpression(file.addHelper("temporalRef"), [
     node,
     t.stringLiteral(node.name),
-    file.addHelper("temporalUndefined"),
   ]);
 }
 

packages/babel-runtime/helpers/builtin/es6/temporalRef.js

@@ -0,0 +1,8 @@
+import undef from "./temporalUndefined";
+export default function _temporalRef(val, name) {
+  if (val === undef) {
+    throw new ReferenceError(name + " is not defined - temporal dead zone");
+  } else {
+    return val;
+  }
+}

packages/babel-runtime/helpers/builtin/temporalRef.js

@@ -0,0 +1,11 @@
+var temporalUndefined = require("./temporalUndefined");
+
+function _temporalRef(val, name) {
+  if (val === temporalUndefined) {
+    throw new ReferenceError(name + " is not defined - temporal dead zone");
+  } else {
+    return val;
+  }
+}
+
+module.exports = _temporalRef;

packages/babel-runtime/helpers/es6/temporalRef.js

@@ -0,0 +1,8 @@
+import undef from "./temporalUndefined";
+export default function _temporalRef(val, name) {
+  if (val === undef) {
+    throw new ReferenceError(name + " is not defined - temporal dead zone");
+  } else {
+    return val;
+  }
+}

packages/babel-runtime/helpers/temporalRef.js

@@ -0,0 +1,11 @@
+var temporalUndefined = require("./temporalUndefined");
+
+function _temporalRef(val, name) {
+  if (val === temporalUndefined) {
+    throw new ReferenceError(name + " is not defined - temporal dead zone");
+  } else {
+    return val;
+  }
+}
+
+module.exports = _temporalRef;

packages/babel-runtime/scripts/build-dist.js

@@ -99,6 +99,15 @@ function buildRuntimeRewritePlugin(relativePath, helperName, dependencies) {
   };
 }
 
+function buildRequireCall(id, dep) {
+  return t.variableDeclaration("var", [
+    t.variableDeclarator(
+      id,
+      t.callExpression(t.identifier("require"), [t.stringLiteral(dep)])
+    )
+  ]);
+}
+
 function buildHelper(helperName, modules, useBuiltIns) {
   const id =
     modules === "commonjs"
@@ -106,12 +115,31 @@ function buildHelper(helperName, modules, useBuiltIns) {
       : null;
   const sourceType = modules === "commonjs" ? "script" : "module";
 
-  const helper = helpers.get(helperName, null, id);
-  const tree = t.program(helper.nodes, [], sourceType);
+  const tree = t.program([], [], sourceType);
+  const dependencies = {};
+  let bindings = null;
+
+  if (modules === "commonjs") {
+    bindings = [];
+    for (const dep of helpers.getDependencies(helperName)) {
+      const id = dependencies[dep] = t.identifier(t.toIdentifier(dep));
+      tree.body.push(buildRequireCall(id, dep));
+      bindings.push(id.name);
+    }
+  }
+
+  const helper = helpers.get(
+    helperName,
+    dep => dependencies[dep],
+    id,
+    bindings
+  );
+  tree.body.push.apply(tree.body, helper.nodes);
+
   const transformOpts = makeTransformOpts(modules, useBuiltIns);
 
   const relative = useBuiltIns ? "../.." : "..";
-
+  
   return babel.transformFromAst(tree, null, {
     presets: transformOpts.presets,
     plugins: transformOpts.plugins.concat([