Conditionally add PUSH_CERTIFICATES change option

If the server config reports that signed pushes are enabled, then we
need to add the PUSH_CERTIFICATES bit to our change detail request
options. This change will fetch the server config (if it's not already
pending or resolved) and wait for it to resolve before sending the
change detail request.

Change-Id: I8a919a50a278588aa342fa31529911274fec9ca5
(cherry picked from commit 7dc7f91bc49b69c1533891a9d81e3a7f27d98ccd)
diff --git a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.js b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.js
index 2a1ad9e..fd25908 100644
--- a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.js
+++ b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface.js
@@ -1297,21 +1297,27 @@
      * @param {function()=} opt_cancelCondition
      */
     getChangeDetail(changeNum, opt_errFn, opt_cancelCondition) {
-      const options = this.listChangesOptionsToHex(
-          this.ListChangesOption.ALL_COMMITS,
-          this.ListChangesOption.ALL_REVISIONS,
-          this.ListChangesOption.CHANGE_ACTIONS,
-          this.ListChangesOption.CURRENT_ACTIONS,
-          this.ListChangesOption.DETAILED_LABELS,
-          this.ListChangesOption.DOWNLOAD_COMMANDS,
-          this.ListChangesOption.MESSAGES,
-          this.ListChangesOption.SUBMITTABLE,
-          this.ListChangesOption.WEB_LINKS,
-          this.ListChangesOption.SKIP_MERGEABLE
-      );
-      return this._getChangeDetail(
-          changeNum, options, opt_errFn, opt_cancelCondition)
-          .then(GrReviewerUpdatesParser.parse);
+      const options = [
+        this.ListChangesOption.ALL_COMMITS,
+        this.ListChangesOption.ALL_REVISIONS,
+        this.ListChangesOption.CHANGE_ACTIONS,
+        this.ListChangesOption.CURRENT_ACTIONS,
+        this.ListChangesOption.DETAILED_LABELS,
+        this.ListChangesOption.DOWNLOAD_COMMANDS,
+        this.ListChangesOption.MESSAGES,
+        this.ListChangesOption.SUBMITTABLE,
+        this.ListChangesOption.WEB_LINKS,
+        this.ListChangesOption.SKIP_MERGEABLE,
+      ];
+      return this.getConfig(false).then(config => {
+        if (config.receive && config.receive.enable_signed_push) {
+          options.push(this.ListChangesOption.PUSH_CERTIFICATES);
+        }
+        const optionsHex = this.listChangesOptionsToHex(...options);
+        return this._getChangeDetail(
+            changeNum, optionsHex, opt_errFn, opt_cancelCondition)
+            .then(GrReviewerUpdatesParser.parse);
+      });
     },
 
     /**
diff --git a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.html b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.html
index eaac5ef..b3496ce 100644
--- a/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.html
+++ b/polygerrit-ui/app/elements/shared/gr-rest-api-interface/gr-rest-api-interface_test.html
@@ -722,15 +722,6 @@
       assert.deepEqual(element._send.lastCall.args[0].body, {token: 'foo'});
     });
 
-    test('GrReviewerUpdatesParser.parse is used', () => {
-      sandbox.stub(GrReviewerUpdatesParser, 'parse').returns(
-          Promise.resolve('foo'));
-      return element.getChangeDetail(42).then(result => {
-        assert.isTrue(GrReviewerUpdatesParser.parse.calledOnce);
-        assert.equal(result, 'foo');
-      });
-    });
-
     test('setAccountStatus', () => {
       sandbox.stub(element, '_send').returns(Promise.resolve('OOO'));
       element._cache.set('/accounts/self/detail', {});
@@ -1031,7 +1022,49 @@
       });
     });
 
-    suite('_getChangeDetail', () => {
+    suite('getChangeDetail', () => {
+      suite('change detail options', () => {
+        let toHexStub;
+
+        setup(() => {
+          toHexStub = sandbox.stub(element, 'listChangesOptionsToHex',
+              options => 'deadbeef');
+          sandbox.stub(element, '_getChangeDetail',
+              async (changeNum, options) => ({changeNum, options}));
+        });
+
+        test('signed pushes disabled', async () => {
+          const {PUSH_CERTIFICATES} = element.ListChangesOption;
+          sandbox.stub(element, 'getConfig', async () => ({}));
+          const {changeNum, options} = await element.getChangeDetail(123);
+          assert.strictEqual(123, changeNum);
+          assert.strictEqual('deadbeef', options);
+          assert.isTrue(toHexStub.calledOnce);
+          assert.isFalse(toHexStub.lastCall.args.includes(PUSH_CERTIFICATES));
+        });
+
+        test('signed pushes enabled', async () => {
+          const {PUSH_CERTIFICATES} = element.ListChangesOption;
+          sandbox.stub(element, 'getConfig', async () => {
+            return {receive: {enable_signed_push: true}};
+          });
+          const {changeNum, options} = await element.getChangeDetail(123);
+          assert.strictEqual(123, changeNum);
+          assert.strictEqual('deadbeef', options);
+          assert.isTrue(toHexStub.calledOnce);
+          assert.isTrue(toHexStub.lastCall.args.includes(PUSH_CERTIFICATES));
+        });
+      });
+
+      test('GrReviewerUpdatesParser.parse is used', () => {
+        sandbox.stub(GrReviewerUpdatesParser, 'parse').returns(
+            Promise.resolve('foo'));
+        return element.getChangeDetail(42).then(result => {
+          assert.isTrue(GrReviewerUpdatesParser.parse.calledOnce);
+          assert.equal(result, 'foo');
+        });
+      });
+
       test('_getChangeDetail passes params to ETags decorator', () => {
         const changeNum = 4321;
         element._projectLookup[changeNum] = 'test';