never return broken modules from require

ember-cli · Jun 24, 2016 · d3dea19 · d3dea19
1 parent af9c05d
commit d3dea19
Showing 1 changed file with 32 additions and 6 deletions.
diff --git a/lib/loader/loader.js b/lib/loader/loader.js
@@ -90,10 +90,21 @@ var loader, define, requireModule, require, requirejs;
     this.deps      = !deps.length && callback.length ? defaultDeps : deps;
     this.module    = { exports: {} };
     this.callback  = callback;
-    this.state = 'new';
     this.hasExportsAsDep = false;
     this.isAlias = alias;
     this.reified = new Array(deps.length);
+
+    /*
+       Each module normally passes through these states, in order:
+         new       : initial state
+         pending   : this module is scheduled to be executed
+         reifying  : this module's dependencies are being executed
+         reified   : this module's dependencies finished executing successfully
+         errored   : this module's dependencies failed to execute
+         finalized : this module executed successfully
+     */
+    this.state = 'new';
+
   }
 
   Module.prototype.makeDefaultExport = function() {
@@ -106,18 +117,19 @@ var loader, define, requireModule, require, requirejs;
   };
 
   Module.prototype.exports = function() {
-    if (this.state === 'finalized') { return this.module.exports; }
+    // if finalized, there is no work to do. If reifying, there is a
+    // circular dependency so we must return our (partial) exports.
+    if (this.state === 'finalized' || this.state === 'reifying') { return this.module.exports; }
     stats.exports++;
 
-    this.state = 'finalized';
-
     if (loader.wrapModules) {
       this.callback = loader.wrapModules(this.name, this.callback);
     }
 
     this.reify();
 
     var result = this.callback.apply(this, this.reified);
+    this.state = 'finalized';
 
     if (!(this.hasExportsAsDep && result === undefined)) {
       this.module.exports = result;
@@ -132,12 +144,26 @@ var loader, define, requireModule, require, requirejs;
   };
 
   Module.prototype.reify = function() {
+    if (this.state === 'reified') { return; }
+    this.state = 'reifying';
+    try {
+      this.reified = this._reify();
+      this.state = 'reified';
+    } finally {
+      if (this.state === 'reifying') {
+        this.state = 'errored';
+      }
+    }
+  };
+
+  Module.prototype._reify = function() {
     stats.reify++;
-    var reified = this.reified;
+    var reified = this.reified.slice();
     for (var i = 0; i < reified.length; i++) {
       var mod = reified[i];
       reified[i] = mod.exports ? mod.exports : mod.module.exports();
     }
+    return reified;
   };
 
   Module.prototype.findDeps = function(pending) {
@@ -223,7 +249,7 @@ var loader, define, requireModule, require, requirejs;
 
     if (!mod) { missingModule(name, referrer); }
 
-    if (pending && mod.state === 'new') {
+    if (pending && mod.state !== 'pending' && mod.state !== 'finalized') {
       mod.findDeps(pending);
       pending.push(mod);
       stats.pendingQueueLength++;