Remove Edge as a default product, but add breadcrumb link

After a lot of discussion, we have decided to remove Edge as a default
product from wpt.fyi due to overlap in browser engine between Chrome and
Edge. In a perfect world we would invest in per-user default products,
but there is no resourcing for that currently.

To try to minimize the disruption, we add a breadcrumb link back to
easily let users get Edge back on the page.

See #1519

api/query/atoms.go

@@ -45,8 +45,6 @@ import (
 	"github.com/web-platform-tests/wpt.fyi/shared"
 )
 
-var browsers = shared.GetDefaultBrowserNames()
-
 // AbstractQuery is an intermetidate representation of a test results query that
 //  has not been bound to specific shared.TestRun specs for processing.
 type AbstractQuery interface {

shared/browsers.go

@@ -9,12 +9,12 @@ import (
 // A list of browsers that are shown on the homepage by default.
 // (Must be sorted alphabetically!)
 var defaultBrowsers = []string{
-	"chrome", "edge", "firefox", "safari",
+	"chrome", "firefox", "safari",
 }
 
 // An extra list of known browsers.
 var extraBrowsers = []string{
-	"android_webview", "epiphany", "servo", "uc", "webkitgtk",
+	"android_webview", "edge", "epiphany", "servo", "uc", "webkitgtk",
 }
 
 var allBrowsers mapset.Set

webapp/components/product-info.js

@@ -42,7 +42,9 @@ const AllBrowserNames = Object.freeze(['chrome', 'edge', 'firefox', 'safari', 's
 // The list of default browsers used in cases where the user has not otherwise
 // chosen a set of browsers (e.g. which browsers to show runs for). Stored as
 // an ordered list so that the first entry can be used as a consistent default.
-const DefaultBrowserNames = Object.freeze(['chrome', 'edge', 'firefox', 'safari']);
+//
+// This should be kept in sync with defaultBrowsers in shared/browsers.go
+const DefaultBrowserNames = Object.freeze(['chrome', 'firefox', 'safari']);
 const DefaultProductSpecs = DefaultBrowserNames;
 
 // The above sets, encoded as product objects. This avoids repeatedly calling

webapp/views/wpt-app.js

@@ -1,4 +1,5 @@
 import { PathInfo } from '../components/path.js';
+import { DefaultBrowserNames } from '../components/product-info.js';
 import '../components/test-runs-query-builder.js';
 import { TestRunsUIBase } from '../components/test-runs.js';
 import '../components/test-search.js';
@@ -130,6 +131,9 @@ class WPTApp extends PathInfo(WPTFlags(TestRunsUIBase)) {
           <template is="dom-if" if="[[!editable]]">
             <a href="javascript:window.location.search='';"> (switch to the default product set instead)</a>
           </template>
+          <template is="dom-if" if="[[showAddEdgeBackLink(queryParams)]]">
+            <a href='#' on-click="addEdgeBack"> (add Microsoft Edge back)</a>
+          </template>
           <wpt-permalinks path="[[path]]"
                           path-prefix="/[[page]]/"
                           query-params="[[queryParams]]"
@@ -386,6 +390,21 @@ class WPTApp extends PathInfo(WPTFlags(TestRunsUIBase)) {
     return true;
   }
 
+  showAddEdgeBackLink(queryParams) {
+    // We only show the 'add edge' link when the user has originally gone to
+    // the main page (e.g. just https://wpt.fyi/results). We can detect that by
+    // checking that no products were specified.
+    return queryParams.product === undefined;
+  }
+
+  addEdgeBack() {
+    // Attempt to put Edge back in the place it used to go (next to Chrome),
+    // but also allow for some change in the default browser set.
+    const newProducts = [DefaultBrowserNames[0], 'edge', ...DefaultBrowserNames.slice(1)];
+    this.queryParams.product = newProducts;
+    this.updateQueryParams(this.queryParams);
+  }
+
   computeResultsTotalsRangeMessage(page, path, searchResults, shas, productSpecs, from, to, maxCount, labels, master, runIds) {
     const msg = super.computeResultsRangeMessage(shas, productSpecs, from, to, maxCount, labels, master, runIds);
     if (page === 'results' && searchResults) {