Add removeReferences config option. (#33)

This option will remove any triple-slash references to these type
declaration files, specified as paths relative to the analysis root
directory.

This is useful for pruning out generated references that we don't
actually need, e.g. from Polymer to ShadyCSS.

Also renames augment to addReferences, because I think the two make more
sense together this way.

src/gen-ts.ts

@@ -26,12 +26,18 @@ export interface Config {
    */
   exclude?: string[];
 
+  /**
+   * Remove any triple-slash references to these files, specified as paths
+   * relative to the analysis root directory.
+   */
+  removeReferences?: string[];
+
   /**
    * Additional files to insert as triple-slash reference statements. Given the
    * map `a: b[]`, a will get an additional reference statement for each file
-   * path in b.
+   * path in b. All paths are relative to the analysis root directory.
    */
-  augment?: {[filepath: string]: string[]};
+  addReferences?: {[filepath: string]: string[]};
 }
 
 /**
@@ -46,7 +52,7 @@ export async function generateDeclarations(
   });
   const analysis = await a.analyzePackage();
   const outFiles = new Map<string, string>();
-  for (const tsDoc of analyzerToAst(analysis, config)) {
+  for (const tsDoc of analyzerToAst(analysis, config, rootDir)) {
     outFiles.set(tsDoc.path, tsDoc.serialize())
   }
   return outFiles;
@@ -57,11 +63,14 @@ export async function generateDeclarations(
  * result.
  */
 function analyzerToAst(
-    analysis: analyzer.Analysis, config: Config): ts.Document[] {
+    analysis: analyzer.Analysis, config: Config, rootDir: string):
+    ts.Document[] {
   const exclude = config.exclude !== undefined ?
       config.exclude.map((p) => new RegExp(p)) :
       [/test\//, /demo\//];
-  const augment = config.augment || {};
+  const addReferences = config.addReferences || {};
+  const removeReferencesResolved = new Set(
+      (config.removeReferences || []).map((r) => path.resolve(rootDir, r)));
 
   // Analyzer can produce multiple JS documents with the same URL (e.g. an
   // HTML file with multiple inline scripts). We also might have multiple
@@ -92,8 +101,14 @@ function analyzerToAst(
     for (const analyzerDoc of analyzerDocs) {
       handleDocument(analyzerDoc, tsDoc);
     }
-    for (const a of augment[tsDoc.path] || []) {
-      tsDoc.referencePaths.add(path.relative(path.dirname(tsDoc.path), a));
+    for (const ref of tsDoc.referencePaths) {
+      const resolvedRef = path.resolve(rootDir, path.dirname(tsDoc.path), ref);
+      if (removeReferencesResolved.has(resolvedRef)) {
+        tsDoc.referencePaths.delete(ref);
+      }
+    }
+    for (const ref of addReferences[tsDoc.path] || []) {
+      tsDoc.referencePaths.add(path.relative(path.dirname(tsDoc.path), ref));
     }
     tsDoc.simplify();
     // Include even documents with no members. They might be dependencies of

src/test/goldens/polymer/lib/elements/custom-style.d.ts

@@ -8,7 +8,6 @@
  *   lib/elements/custom-style.html
  */
 
-/// <reference path="../../../shadycss/custom-style-interface.d.ts" />
 /// <reference path="../utils/style-gather.d.ts" />
 
 declare namespace Polymer {

src/test/goldens/polymer/lib/legacy/legacy-element-mixin.d.ts

@@ -8,7 +8,6 @@
  *   lib/legacy/legacy-element-mixin.html
  */
 
-/// <reference path="../../../shadycss/apply-shim.d.ts" />
 /// <reference path="../mixins/element-mixin.d.ts" />
 /// <reference path="../mixins/gesture-event-listeners.d.ts" />
 /// <reference path="../mixins/dir-mixin.d.ts" />