Merge pull request #16 from Polymer/ignore-remote-files

Ignore remote files during build

src/get-dependencies-from-document.ts

@@ -8,16 +8,31 @@
  * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
  */
 
+import {parse as urlParse} from 'url';
 import {DocumentDescriptor} from 'hydrolysis';
 import {posix as posixPath} from 'path';
 import {Node, queryAll, predicates, getAttribute} from 'dom5';
+import * as logging from 'plylog';
+
+const logger = logging.getLogger('cli.build.get-dependencies');
 
 export interface DocumentDeps {
   imports?: Array<string>;
   scripts?: Array<string>;
   styles?: Array<string>;
 }
 
+/**
+ * Detects if a url is external by checking it's protocol. Also checks if it
+ * starts with '//', which can be an alias to the page's current protocol
+ * in the browser.
+ */
+function isDependencyExternal(url: string) {
+  // TODO(fks) 08-01-2016: Add additional check for files on current hostname
+  // but external to this application root. Ignore them.
+  return urlParse(url).protocol !== null || url.startsWith('//');
+}
+
 function collectScriptsAndStyles(tree: DocumentDescriptor): DocumentDeps {
   let scripts: string[] = [];
   let styles: string[] = [];
@@ -40,14 +55,37 @@ function collectScriptsAndStyles(tree: DocumentDescriptor): DocumentDeps {
   };
 }
 
+/**
+ * Returns a collection of all local dependencies from a DocumentDescriptor
+ * object, ignoring any external dependencies. Because HTML imports can have
+ * script and style dependencies of their own, this will recursively call
+ * itself down the import tree to collect all dependencies.
+ */
 export function getDependenciesFromDocument(descriptor: DocumentDescriptor, dir: string): DocumentDeps {
   let allHtmlDeps: string[] = [];
   let allScriptDeps = new Set<string>();
   let allStyleDeps = new Set<string>();
-
   let deps: DocumentDeps = collectScriptsAndStyles(descriptor);
-  deps.scripts.forEach((s) => allScriptDeps.add(posixPath.join(dir, s)));
-  deps.styles.forEach((s) => allStyleDeps.add(posixPath.join(dir, s)));
+
+  // Collect all script dependencies
+  deps.scripts.forEach((scriptDep) => {
+    if (isDependencyExternal(scriptDep)) {
+      logger.debug('external dependency ignored', {dep: scriptDep});
+      return;
+    }
+    allScriptDeps.add(posixPath.join(dir, scriptDep));
+  });
+
+  // Collect all style dependencies
+  deps.styles.forEach((styleDep) => {
+    if (isDependencyExternal(styleDep)) {
+      logger.debug('external dependency ignored', {dep: styleDep});
+      return;
+    }
+    allStyleDeps.add(posixPath.join(dir, styleDep));
+  });
+
+  // Recursively collects and analyzes all HTML imports and their dependencies
   if (descriptor.imports) {
     let queue = descriptor.imports.slice();
     let next: DocumentDescriptor;

test/test-project/shell.html

@@ -1,4 +1,6 @@
 <link rel="import" href="bower_components/dep.html">
+<!-- remote dependencies should be ignored during build -->
+<link rel="stylesheet" href="https://example.com/style.min.css">
 
 <div id="A"></div>