typeahead: Pass input element to source instead of using hacky this.

web/src/bootstrap_typeahead.ts

@@ -203,7 +203,7 @@ class Typeahead<ItemType extends string | object> {
     $container: JQuery;
     $menu: JQuery;
     $header: JQuery;
-    source: (query: string) => ItemType[];
+    source: (query: string, input_element: InputElement) => ItemType[];
     dropup: boolean;
     fixed: boolean;
     automated: () => boolean;
@@ -377,7 +377,7 @@ class Typeahead<ItemType extends string | object> {
             return this.shown ? this.hide() : this;
         }
 
-        const items = this.source(this.query);
+        const items = this.source(this.query, this.input_element);
 
         if (!items && this.shown) {
             this.hide();
@@ -694,7 +694,7 @@ class Typeahead<ItemType extends string | object> {
 type TypeaheadOptions<ItemType> = {
     highlighter_html: (item: ItemType, query: string) => string | undefined;
     items: number;
-    source: (query: string) => ItemType[];
+    source: (query: string, input_element: InputElement) => ItemType[];
     // optional options
     advanceKeyCodes?: number[];
     automated?: () => boolean;

web/src/composebox_typeahead.js

@@ -600,9 +600,9 @@ export function get_person_suggestions(query, opts) {
     });
 }
 
-export function get_stream_topic_data(hacky_this) {
+export function get_stream_topic_data(input_element) {
     const opts = {};
-    const $message_row = hacky_this.input_element.$element.closest(".message_row");
+    const $message_row = input_element.$element.closest(".message_row");
     if ($message_row.length === 1) {
         // we are editing a message so we try to use its keys.
         const msg = message_store.get(rows.id($message_row));
@@ -617,7 +617,7 @@ export function get_stream_topic_data(hacky_this) {
     return opts;
 }
 
-export function get_sorted_filtered_items(query) {
+export function get_sorted_filtered_items(query, input_element) {
     /*
         This is just a "glue" function to work
         around bootstrap.  We want to control these
@@ -641,14 +641,13 @@ export function get_sorted_filtered_items(query) {
         several years ago.)
     */
 
-    const fetcher = get_candidates.bind(this);
-    const big_results = fetcher(query);
+    const big_results = get_candidates(query, input_element);
 
     if (!big_results) {
         return false;
     }
 
-    const opts = get_stream_topic_data(this);
+    const opts = get_stream_topic_data(input_element);
 
     if (completing === "mention" || completing === "silent_mention") {
         return filter_and_sort_mentions(big_results.is_silent, token, opts);
@@ -678,8 +677,8 @@ const ALLOWED_MARKDOWN_FEATURES = {
     timestamp: true,
 };
 
-export function get_candidates(query) {
-    const split = split_at_cursor(query, this.input_element.$element);
+export function get_candidates(query, input_element) {
+    const split = split_at_cursor(query, input_element.$element);
     let current_token = tokenize_compose_str(split[0]);
     if (current_token === "") {
         return false;

web/tests/composebox_typeahead.test.js

@@ -987,19 +987,17 @@ test("initialize", ({override, override_rewire, mock_template}) => {
                 // For now we only test that get_sorted_filtered_items has been
                 // properly set as the .source(). All its features are tested later on
                 // in test_begins_typeahead().
-                const fake_this = {
-                    input_element: {
-                        $element: {},
-                        type: "input",
-                    },
+                const input_element = {
+                    $element: {},
+                    type: "input",
                 };
                 let caret_called = false;
-                fake_this.input_element.$element.caret = () => {
+                input_element.$element.caret = () => {
                     caret_called = true;
                     return 7;
                 };
-                fake_this.input_element.$element.closest = () => [];
-                let actual_value = options.source.call(fake_this, "test #s");
+                input_element.$element.closest = () => [];
+                let actual_value = options.source("test #s", input_element);
                 assert.deepEqual(sorted_names_from(actual_value), ["Sweden", "The Netherlands"]);
                 assert.ok(caret_called);
 
@@ -1330,29 +1328,15 @@ test("begins_typeahead", ({override, override_rewire}) => {
     });
     override(stream_topic_history_util, "get_server_history", noop);
 
-    const begin_typehead_this = {
-        input_element: {
-            $element: {},
-            type: "input",
-        },
-        options: {
-            completions: {
-                emoji: true,
-                mention: true,
-                silent_mention: true,
-                slash: true,
-                stream: true,
-                syntax: true,
-                topic: true,
-                timestamp: true,
-            },
-        },
+    const input_element = {
+        $element: {},
+        type: "input",
     };
 
     function get_values(input, rest) {
         // Stub out split_at_cursor that uses $(':focus')
         override_rewire(ct, "split_at_cursor", () => [input, rest]);
-        const values = ct.get_candidates.call(begin_typehead_this, input);
+        const values = ct.get_candidates(input, input_element);
         return values;
     }