search: Use e.key instead of deprecated e.which.

Tested by making sure Enter works and expected in the navbar search
with and without the typeahead being present.

frontend_tests/node_tests/search.js

@@ -228,7 +228,7 @@ test("initialize", () => {
     let default_prevented = false;
     let ev = {
         type: "keydown",
-        which: 15,
+        key: "a",
         preventDefault() {
             default_prevented = true;
         },
@@ -237,11 +237,11 @@ test("initialize", () => {
     assert.equal(keydown(ev), undefined);
     assert(!default_prevented);
 
-    ev.which = 13;
+    ev.key = "Enter";
     assert.equal(keydown(ev), undefined);
     assert(!default_prevented);
 
-    ev.which = 13;
+    ev.key = "Enter";
     search_query_box.is = () => true;
     assert.equal(keydown(ev), undefined);
     assert(default_prevented);
@@ -288,14 +288,14 @@ test("initialize", () => {
     assert(!is_blurred);
     assert(!search_button.prop("disabled"));
 
-    ev.which = 13;
+    ev.key = "Enter";
     search_query_box.is = () => false;
     searchbox_form.trigger(ev);
 
     assert(!is_blurred);
     assert(!search_button.prop("disabled"));
 
-    ev.which = 13;
+    ev.key = "Enter";
     search_query_box.is = () => true;
     searchbox_form.trigger(ev);
     assert(is_blurred);
@@ -308,7 +308,7 @@ test("initialize", () => {
     assert(!search_button.prop("disabled"));
 
     _setup("ver");
-    ev.which = 13;
+    ev.key = "Enter";
     search_query_box.is = () => true;
     searchbox_form.trigger(ev);
     assert(is_blurred);

frontend_tests/node_tests/search_legacy.js

@@ -192,11 +192,11 @@ run_test("initialize", () => {
     assert.equal(keydown(ev), undefined);
     assert(!default_prevented);
 
-    ev.which = 13;
+    ev.key = "Enter";
     assert.equal(keydown(ev), undefined);
     assert(!default_prevented);
 
-    ev.which = 13;
+    ev.key = "Enter";
     search_query_box.is = () => true;
     assert.equal(keydown(ev), undefined);
     assert(default_prevented);
@@ -235,21 +235,21 @@ run_test("initialize", () => {
     ];
     _setup("");
 
-    ev.which = 15;
+    ev.key = "a";
     search_query_box.is = () => false;
     searchbox_form.trigger(ev);
 
     assert(!is_blurred);
     assert(!search_button.prop("disabled"));
 
-    ev.which = 13;
+    ev.key = "Enter";
     search_query_box.is = () => false;
     searchbox_form.trigger(ev);
 
     assert(!is_blurred);
     assert(!search_button.prop("disabled"));
 
-    ev.which = 13;
+    ev.key = "Enter";
     search_query_box.is = () => true;
     searchbox_form.trigger(ev);
     assert(is_blurred);
@@ -262,7 +262,7 @@ run_test("initialize", () => {
     assert(!search_button.prop("disabled"));
 
     _setup("ver");
-    ev.which = 13;
+    ev.key = "Enter";
     search_query_box.is = () => true;
     searchbox_form.trigger(ev);
     assert(is_blurred);

static/js/search.js

@@ -134,8 +134,7 @@ export function initialize() {
     searchbox_form
         .on("keydown", (e) => {
             update_button_visibility();
-            const code = e.which;
-            if (code === 13 && search_query_box.is(":focus")) {
+            if (e.key === "Enter" && search_query_box.is(":focus")) {
                 // Don't submit the form so that the typeahead can instead
                 // handle our Enter keypress. Any searching that needs
                 // to be done will be handled in the keyup.
@@ -147,8 +146,8 @@ export function initialize() {
                 is_using_input_method = false;
                 return;
             }
-            const code = e.which;
-            if (code === 13 && search_query_box.is(":focus")) {
+
+            if (e.key === "Enter" && search_query_box.is(":focus")) {
                 // We just pressed Enter and the box had focus, which
                 // means we didn't use the typeahead at all.  In that
                 // case, we should act as though we're searching by