From 4c02e246f7872075076b6c8c22a91a71f1131701 Mon Sep 17 00:00:00 2001
From: Dima Voytenko <dvoytenko@google.com>
Date: Fri, 15 Jan 2016 13:54:32 -0800
Subject: [PATCH] isDevChannel method and whitelist for access

---
 build-system/tasks/presubmit-checks.js  | 17 ++++++++++++++
 extensions/amp-access/0.1/amp-access.js |  5 +++--
 src/experiments.js                      | 30 +++++++++++++++++++++++++
 test/functional/test-experiments.js     | 25 ++++++++++++++++++++-
 4 files changed, 74 insertions(+), 3 deletions(-)

diff --git a/build-system/tasks/presubmit-checks.js b/build-system/tasks/presubmit-checks.js
index 520c9f26bb6c..f2c70fffe5cc 100644
--- a/build-system/tasks/presubmit-checks.js
+++ b/build-system/tasks/presubmit-checks.js
@@ -33,6 +33,9 @@ var privateServiceFactory = 'This service should only be installed in ' +
     'the whitelisted files. Other modules should use a public function ' +
     'typically called serviceNameFor.';
 
+var shouldNeverBeUsed =
+    'Usage of this API is not allowed - only for internal purposes.';
+
 // Terms that must not appear in our source files.
 var forbiddenTerms = {
   'DO NOT SUBMIT': '',
@@ -151,6 +154,20 @@ var forbiddenTerms = {
       'tools/experiments/experiments.js',
     ]
   },
+  'isDevChannel\\W': {
+    message: requiresReviewPrivacy,
+    whitelist: [
+      'extensions/amp-access/0.1/amp-access.js',
+      'src/experiments.js',
+      'tools/experiments/experiments.js',
+    ]
+  },
+  'isDevChannelVersionDoNotUse_\\W': {
+    message: shouldNeverBeUsed,
+    whitelist: [
+      'src/experiments.js',
+    ]
+  },
   'eval\\(': '',
   'localStorage': {
     message: requiresReviewPrivacy,
diff --git a/extensions/amp-access/0.1/amp-access.js b/extensions/amp-access/0.1/amp-access.js
index 1abf4b575533..5801da62b247 100644
--- a/extensions/amp-access/0.1/amp-access.js
+++ b/extensions/amp-access/0.1/amp-access.js
@@ -23,7 +23,7 @@ import {documentStateFor} from '../../../src/document-state';
 import {evaluateAccessExpr} from './access-expr';
 import {getService} from '../../../src/service';
 import {installStyles} from '../../../src/styles';
-import {isExperimentOn} from '../../../src/experiments';
+import {isDevChannel, isExperimentOn} from '../../../src/experiments';
 import {listenOnce} from '../../../src/event-helper';
 import {log} from '../../../src/log';
 import {onDocumentReady} from '../../../src/document-state';
@@ -91,7 +91,8 @@ export class AccessService {
     installStyles(this.win.document, $CSS$, () => {});
 
     /** @const @private {boolean} */
-    this.isExperimentOn_ = isExperimentOn(this.win, EXPERIMENT);
+    this.isExperimentOn_ = (isExperimentOn(this.win, EXPERIMENT) ||
+        isDevChannel(this.win));
 
     const accessElement = document.getElementById('amp-access');
 
diff --git a/src/experiments.js b/src/experiments.js
index a24724ee36ff..2b20b0157805 100644
--- a/src/experiments.js
+++ b/src/experiments.js
@@ -34,6 +34,36 @@ const COOKIE_MAX_AGE_DAYS = 180;  // 6 month
 /** @const {time} */
 const COOKIE_EXPIRATION_INTERVAL = COOKIE_MAX_AGE_DAYS * 24 * 60 * 60 * 1000;
 
+/** @const {string} */
+const CANARY_EXPERIMENT_ID = 'dev-channel';
+
+
+/**
+ * Whether the scripts come from a dev channel.
+ * @param {!Window} win
+ * @return {boolean}
+ */
+export function isDevChannel(win) {
+  if (isExperimentOn(win, CANARY_EXPERIMENT_ID)) {
+    return true;
+  }
+  if (isDevChannelVersionDoNotUse_('$internalRuntimeVersion$')) {
+    return true;
+  }
+  return false;
+}
+
+
+/**
+ * Whether the version corresponds to the dev-channel binary.
+ * @param {string} version
+ * @return {boolean}
+ * @private Visible for testing only!
+ */
+export function isDevChannelVersionDoNotUse_(version) {
+  return !!version.match(/\-canary$/);
+}
+
 
 /**
  * Whether the specified experiment is on or off.
diff --git a/test/functional/test-experiments.js b/test/functional/test-experiments.js
index 8d7c78b89754..e2e3b38b68fb 100644
--- a/test/functional/test-experiments.js
+++ b/test/functional/test-experiments.js
@@ -14,7 +14,8 @@
  * limitations under the License.
  */
 
-import {isExperimentOn, toggleExperiment} from '../../src/experiments';
+import {isDevChannel, isDevChannelVersionDoNotUse_,
+    isExperimentOn, toggleExperiment} from '../../src/experiments';
 import * as sinon from 'sinon';
 
 
@@ -110,3 +111,25 @@ describe('toggleExperiment', () => {
     expectToggle('AMP_EXP=e1', 'e1', false).to.equal('false; AMP_EXP=');
   });
 });
+
+
+describe('isDevChannel', () => {
+
+  function expectDevChannel(cookiesString) {
+    return expect(isDevChannel({
+      document: {
+        cookie: cookiesString
+      }
+    }));
+  }
+
+  it('should return value based on cookie', () => {
+    expectDevChannel('AMP_EXP=other').to.be.false;
+    expectDevChannel('AMP_EXP=dev-channel').to.be.true;
+  });
+
+  it('should return value based on binary version', () => {
+    expect(isDevChannelVersionDoNotUse_('123456789')).to.be.false;
+    expect(isDevChannelVersionDoNotUse_('123456789-canary')).to.be.true;
+  });
+});