Add @extends annotations to generated externs

config/jsdoc/info/publish.js

@@ -88,6 +88,9 @@ exports.publish = function(data, opts) {
         stability: doc.api,
         path: path.join(doc.meta.path, doc.meta.filename)
       };
+      if (doc.augments) {
+        symbol.extends = doc.augments[0];
+      }
       if (doc.type) {
         symbol.types = getTypes(doc.type.names);
       }

tasks/generate-externs.js

@@ -93,6 +93,9 @@ function generateExterns(typedefs, symbols, externs, interfaces) {
     if (symbol.kind === 'class') {
       constructors[name] = true;
       lines.push(' * @constructor');
+      if (symbol.extends) {
+        lines.push(' * @extends {' + symbol.extends + '}');
+      }
     }
     if (symbol.types) {
       lines.push(' * @type {' + noGoogTypes(symbol.types).join('|') + '}');