js: Use hasOwnProperty correctly or not at all.

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

frontend_tests/casper_lib/common.js

@@ -170,7 +170,7 @@ exports.check_form = function (form_selector, expected, test_name) {
     var values = casper.getFormValues(form_selector);
     var k;
     for (k in expected) {
-        if (expected.hasOwnProperty(k)) {
+        if (Object.prototype.hasOwnProperty.call(expected, k)) {
             casper.test.assertEqual(values[k], expected[k],
                                     test_name ? test_name + ": " + k : undefined);
         }

frontend_tests/node_tests/typing_status.js

@@ -267,8 +267,7 @@ run_test('basics', () => {
     };
 
     // stub functions to see how may time they are called
-    for (const method in call_count) {
-        if (!call_count.hasOwnProperty(method)) { continue; }
+    for (const method of Object.keys(call_count)) {
         typing_status.__Rewire__(method, function () {
             call_count[method] += 1;
         });

static/js/blueslip.js

@@ -191,9 +191,9 @@ BlueslipError.prototype = Object.create(Error.prototype);
 
 exports.exception_msg = function blueslip_exception_msg(ex) {
     let message = ex.message;
-    if (ex.hasOwnProperty('fileName')) {
+    if (ex.fileName !== undefined) {
         message += " at " + ex.fileName;
-        if (ex.hasOwnProperty('lineNumber')) {
+        if (ex.lineNumber !== undefined) {
             message += ":" + ex.lineNumber;
         }
     }

static/js/localstorage.js

@@ -164,7 +164,7 @@ let warned_of_localstorage = false;
 
 localstorage.supported = function supports_localstorage() {
     try {
-        return window.hasOwnProperty('localStorage') && window.localStorage !== null;
+        return window.localStorage !== undefined && window.localStorage !== null;
     } catch (e) {
         if (!warned_of_localstorage) {
             blueslip.error("Client browser does not support local storage, will lose socket message on reload");

static/js/message_events.js

@@ -21,7 +21,7 @@ function maybe_add_narrowed_messages(messages, msg_list) {
             const elsewhere_messages = [];
 
             for (const elem of messages) {
-                if (data.messages.hasOwnProperty(elem.id)) {
+                if (Object.prototype.hasOwnProperty.call(data.messages, elem.id)) {
                     util.set_match_data(elem, data.messages[elem.id]);
                     new_messages.push(elem);
                 } else {

static/js/popovers.js

@@ -42,11 +42,7 @@ function elem_to_user_id(elem) {
     };
 
     // add back all shallow properties of $.fn.popover to the new proxied version.
-    for (const x in popover) {
-        if (popover.hasOwnProperty(x)) {
-            $.fn.popover[x] = popover[x];
-        }
-    }
+    Object.assign($.fn.popover, popover);
 }($.fn.popover));
 
 function copy_email_handler(e) {

static/js/stats/stats.js

@@ -337,16 +337,13 @@ function round_to_percentages(values, total) {
 // Last label will turn into "Other" if time_series data has a label not in labels
 function compute_summary_chart_data(time_series_data, num_steps, labels_) {
     const data = new Map();
-    for (const key in time_series_data) {
-        if (!time_series_data.hasOwnProperty(key)) {
-            continue;
-        }
-        if (time_series_data[key].length < num_steps) {
-            num_steps = time_series_data[key].length;
+    for (const [key, array] of Object.entries(time_series_data)) {
+        if (array.length < num_steps) {
+            num_steps = array.length;
         }
         let sum = 0;
         for (let i = 1; i <= num_steps; i += 1) {
-            sum += time_series_data[key][time_series_data[key].length - i];
+            sum += array[array.length - i];
         }
         data.set(key, sum);
     }

static/js/stream_edit.js

@@ -576,7 +576,7 @@ exports.initialize = function () {
         function invite_success(data) {
             text_box.val('');
 
-            if (data.subscribed.hasOwnProperty(principal)) {
+            if (Object.prototype.hasOwnProperty.call(data.subscribed, principal)) {
                 stream_subscription_info_elem.text(i18n.t("Subscribed successfully!"));
                 // The rest of the work is done via the subscription -> add event we will get
             } else {

static/js/user_groups.js

@@ -91,7 +91,7 @@ exports.initialize = function (params) {
 };
 
 exports.is_user_group = function (item) {
-    return item.hasOwnProperty('members');
+    return item.members !== undefined;
 };
 
 window.user_groups = exports;