js: Convert _.defaults to spread syntax.

This is not always a behavior-preserving translation: _.defaults
mutates its first argument.  However, the code does not always appear
to have been written to expect that.

Signed-off-by: Anders Kaseorg <anders@zulipchat.com>

frontend_tests/node_tests/message_list_view.js

@@ -62,13 +62,15 @@ run_test('msg_edited_vars', () => {
         if (message === undefined) {
             message = {};
         }
-        message_context = _.defaults(message_context, {
+        message_context = {
             include_sender: true,
-        });
-        message_context.msg = _.defaults(message, {
+            ...message_context,
+        };
+        message_context.msg = {
             is_me_message: false,
             last_edit_timestamp: next_timestamp += 1,
-        });
+            ...message,
+        };
         return message_context;
     }
 
@@ -133,10 +135,11 @@ run_test('merge_message_groups', () => {
         if (message === undefined) {
             message = {};
         }
-        message_context = _.defaults(message_context, {
+        message_context = {
             include_sender: true,
-        });
-        message_context.msg = _.defaults(message, {
+            ...message_context,
+        };
+        message_context.msg = {
             id: _.uniqueId('test_message_'),
             status_message: false,
             type: 'stream',
@@ -144,7 +147,8 @@ run_test('merge_message_groups', () => {
             topic: 'Test Subject 1',
             sender_email: 'test@example.com',
             timestamp: next_timestamp += 1,
-        });
+            ...message,
+        };
         return message_context;
     }
 

static/js/narrow.js

@@ -120,12 +120,13 @@ exports.activate = function (raw_operators, opts) {
                                 trigger: opts ? opts.trigger : undefined,
                                 previous_id: current_msg_list.selected_id()});
 
-    opts = _.defaults({}, opts, {
+    opts = {
         then_select_id: -1,
         then_select_offset: undefined,
         change_hash: true,
         trigger: 'unknown',
-    });
+        ...opts,
+    };
 
     const id_info = {
         target_id: undefined,
@@ -678,13 +679,13 @@ exports.by_topic = function (target_id, opts) {
         {operator: 'stream', operand: original.stream},
         {operator: 'topic', operand: original.topic},
     ];
-    opts = _.defaults({}, opts, {then_select_id: target_id});
+    opts = { then_select_id: target_id, ...opts };
     exports.activate(search_terms, opts);
 };
 
 // Called for the 'narrow by stream' hotkey.
 exports.by_recipient = function (target_id, opts) {
-    opts = _.defaults({}, opts, {then_select_id: target_id});
+    opts = { then_select_id: target_id, ...opts };
     // don't use current_msg_list as it won't work for muted messages or for out-of-narrow links
     const message = message_store.get(target_id);
 

static/js/reload.js

@@ -220,13 +220,14 @@ function do_reload_app(send_after_reload, save_pointer, save_narrow, save_compos
 }
 
 exports.initiate = function (options) {
-    options = _.defaults({}, options, {
+    options = {
         immediate: false,
         save_pointer: true,
         save_narrow: true,
         save_compose: true,
         send_after_reload: false,
-    });
+        ...options,
+    };
 
     if (options.save_pointer === undefined ||
         options.save_narrow === undefined ||

static/js/stream_color.js

@@ -59,7 +59,7 @@ exports.set_colorpicker_color = function (colorpicker, color) {
 };
 
 exports.update_stream_color = function (sub, color, opts) {
-    opts = _.defaults({}, opts, {update_historical: false});
+    opts = { update_historical: false, ...opts };
     sub.color = color;
     const stream_id = sub.stream_id;
     // The swatch in the subscription row header.

static/js/stream_data.js

@@ -666,10 +666,11 @@ exports.is_user_subscribed = function (stream_name, user_id) {
 exports.create_streams = function (streams) {
     for (const stream of streams) {
         // We handle subscriber stuff in other events.
-        const attrs = _.defaults(stream, {
+        const attrs = {
             subscribers: [],
             subscribed: false,
-        });
+            ...stream,
+        };
         exports.create_sub_from_server_data(stream.name, attrs);
     }
 };
@@ -698,7 +699,7 @@ exports.create_sub_from_server_data = function (stream_name, attrs) {
 
     delete attrs.subscribers;
 
-    sub = _.defaults(attrs, {
+    sub = {
         name: stream_name,
         render_subscribers: !page_params.realm_is_zephyr_mirror_realm || attrs.invite_only === true,
         subscribed: true,
@@ -712,7 +713,8 @@ exports.create_sub_from_server_data = function (stream_name, attrs) {
         description: '',
         rendered_description: '',
         first_message_id: attrs.first_message_id,
-    });
+        ...attrs,
+    };
 
     exports.set_subscribers(sub, subscriber_user_ids);