🏗 Report unused private fields

.eslintrc

@@ -47,6 +47,7 @@
  "amphtml-internal/no-style-property-setting": 2,
  "amphtml-internal/query-selector": 2,
  "amphtml-internal/todo-format": 0,
+ "amphtml-internal/unused-private-field": 1,
  "amphtml-internal/vsync": 0,
  "array-bracket-spacing": [2, "never"],
  "arrow-parens": [2, "as-needed"],

build-system/eslint-rules/unused-private-field.js

@@ -0,0 +1,101 @@
+/**
+ * Copyright 2018 The AMP HTML Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS-IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+'use strict';
+
+module.exports = function(context) {
+ function stripComments(text) {
+ // Multi-line comments
+ text = text.replace(/\/\*(?!.*\*\/)(.|\n)*?\*\//g, function(match) {
+ // Preserve the newlines
+ const newlines = [];
+ for (let i = 0; i < match.length; i++) {
+ if (match[i] === '\n') {
+ newlines.push('\n');
+ }
+ }
+ return newlines.join('');
+ });
+ // Single line comments either on its own line or following a space,
+ // semi-colon, or closing brace
+ return text.replace(/( |}|;|^) *\/\/.*/g, '$1');
+ }
+
+ function checkClassUse(node, name) {
+ if (!name.endsWith('_')) {
+ return;
+ }
+
+ const comments = context.getCommentsBefore(node);
+ const testing = comments.some(comment => {
+ return /@(visibleForTesting|protected|override)\b/.test(comment.value);
+ });
+ if (testing) {
+ return;
+ }
+
+ const ancestors = context.getAncestors(node);
+ const body = ancestors.reverse().find(node => node.type === 'ClassBody');
+
+ if (!body) {
+ return;
+ }
+
+ // Yah, I know, we're not using the AST anymore.
+ // But there's no good way to do inner traversals, so this is all we got.
+ const source = context.getSourceCode();
+ const bodyText = stripComments(source.getText(body));
+
+ // Requires two uses of the name to qualify;
+ const index = bodyText.indexOf(name);
+ if (!bodyText.includes(name, index + 1)) {
+ context.report(node, `Unused private "${name}".\n` +
+ '\tIf this is used for testing, annotate with "@visibleForTesting"\n' +
+ '\tIf this is a protected definition in a base class,' +
+ ' annotate with "@protected"\n' +
+ '\tIf this is an override of a protected, annotate with "@override"\n');
+ }
+ }
+
+ return {
+ MemberExpression(node) {
+ if (/\btest\b/.test(context.getFilename())) {
+ return;
+ }
+
+ const {property} = node;
+ if (property.type !== 'Identifier') {
+ return;
+ }
+
+ const {name} = property;
+ checkClassUse(node, name);
+ },
+
+ MethodDefinition(node) {
+ if (/\btest\b/.test(context.getFilename())) {
+ return;
+ }
+
+ const {computed, key} = node;
+ if (computed) {
+ return;
+ }
+
+ const {name} = key;
+ checkClassUse(node, name);
+ },
+ };
+};

src/animation.js

@@ -170,10 +170,10 @@ class AnimationPlayer {
  this.startTime_ = 0;
 
  /** @private {./time.normtimeDef} */
- this.normLinearTime_ = 0;
+ // this.normLinearTime_ = 0;
 
  /** @private {./time.normtimeDef} */
- this.normTime_ = 0;
+ // this.normTime_ = 0;
 
  /** @private {boolean} */
  this.running_ = false;