add transformer dependencies - fixes #1477

src/babel/transformation/file/index.js

@@ -29,6 +29,8 @@ import * as t from "../../types";
 
 export default class File {
   constructor(opts = {}, pipeline) {
+    this.transformerDependencies = {};
+
     this.dynamicImportTypes = {};
     this.dynamicImportIds   = {};
     this.dynamicImports     = [];
@@ -221,13 +223,21 @@ export default class File {
     }
     stack = beforePlugins.concat(stack, afterPlugins);
 
-    // register
-    this.transformerStack = this.mergeStack(stack.concat(secondaryStack));
+    // build transformer stack
+    stack = stack.concat(secondaryStack);
 
+    // build dependency graph
+    for (var pass of (stack: Array)) {
+      for (var dep of (pass.transformer.dependencies: Array)) {
+        this.transformerDependencies[dep] = pass.key;
+      }
+    }
 
+    // collapse stack categories
+    this.transformerStack = this.collapseStack(stack);
   }
 
-  mergeStack(_stack) {
+  collapseStack(_stack) {
     var stack  = [];
     var ignore = [];
 

src/babel/transformation/transformer-pass.js

@@ -10,23 +10,24 @@ export default class TransformerPass {
   constructor(file: File, transformer: Transformer) {
     this.transformer = transformer;
     this.handlers    = transformer.handlers;
-    this.skipKey     = transformer.skipKey;
     this.file        = file;
     this.ran         = false;
+    this.key         = transformer.key;
   }
 
   canTransform(): boolean {
-    return this.file.pipeline.canTransform(this.transformer, this.file.opts);
+    return this.file.transformerDependencies[this.key] ||
+           this.file.pipeline.canTransform(this.transformer, this.file.opts);
   }
 
   transform() {
     var file = this.file;
 
-    file.log.debug(`Start transformer ${this.transformer.key}`);
+    file.log.debug(`Start transformer ${this.key}`);
 
     traverse(file.ast, this.handlers, file.scope, file);
 
-    file.log.debug(`Finish transformer ${this.transformer.key}`);
+    file.log.debug(`Finish transformer ${this.key}`);
 
     this.ran = true;
   }

src/babel/transformation/transformer.js

@@ -26,6 +26,7 @@ export default class Transformer {
 
     this.manipulateOptions = take("manipulateOptions");
     this.metadata          = take("metadata") || {};
+    this.dependencies      = this.metadata.dependencies || [];
     this.parser            = take("parser");
     this.post              = take("post");
     this.pre               = take("pre");

src/babel/transformation/transformers/es7/class-properties.js

@@ -1,3 +1,4 @@
 export var metadata = {
-  stage: 0
+  stage: 0,
+  dependencies: ["es6.classes"]
 };

src/babel/transformation/transformers/es7/decorators.js

@@ -3,6 +3,7 @@ import * as defineMap from "../../helpers/define-map";
 import * as t from "../../../types";
 
 export var metadata = {
+  dependencies: ["es6.classes"],
   optional: true,
   stage: 1
 };

src/babel/transformation/transformers/es7/object-rest-spread.js

@@ -3,13 +3,10 @@
 import * as t from "../../../types";
 
 export var metadata = {
-  stage: 1
+  stage: 1,
+  dependencies: ["es6.destructuring"]
 };
 
-export function manipulateOptions(opts) {
-  if (opts.whitelist) opts.whitelist.push("es6.destructuring");
-}
-
 var hasSpread = function (node) {
   for (var i = 0; i < node.properties.length; i++) {
     if (t.isSpreadProperty(node.properties[i])) {

src/babel/transformation/transformers/other/async-to-generator.js

@@ -3,7 +3,8 @@ import remapAsyncToGenerator from "../../helpers/remap-async-to-generator";
 export { manipulateOptions } from "./bluebird-coroutines";
 
 export var metadata = {
-  optional: true
+  optional: true,
+  dependencies: ["es7.asyncFunctions", "es6.classes"]
 };
 
 exports.Function = function (node, parent, scope, file) {

src/babel/transformation/transformers/other/bluebird-coroutines.js

@@ -2,12 +2,12 @@ import remapAsyncToGenerator from "../../helpers/remap-async-to-generator";
 import * as t from "../../../types";
 
 export function manipulateOptions(opts) {
-  opts.optional.push("es7.asyncFunctions");
   opts.blacklist.push("regenerator");
 }
 
 export var metadata = {
-  optional: true
+  optional: true,
+  dependencies: ["es7.asyncFunctions", "es6.classes"]
 };
 
 exports.Function = function (node, parent, scope, file) {