diff --git a/frontend_tests/casper_lib/common.js b/frontend_tests/casper_lib/common.js
index eae16a9338..d724259c5e 100644
--- a/frontend_tests/casper_lib/common.js
+++ b/frontend_tests/casper_lib/common.js
@@ -29,7 +29,7 @@ exports.init_viewport = function () {
     casper.options.viewportSize = {width: 1280, height: 1024};
 };
 
-exports.initialize_casper = function (viewport) {
+exports.initialize_casper = function () {
     if (casper.zulip_initialized !== undefined) {
         return;
     }
diff --git a/frontend_tests/casper_tests/00-realm-creation.js b/frontend_tests/casper_tests/00-realm-creation.js
index 4b3a361f66..f525415395 100644
--- a/frontend_tests/casper_tests/00-realm-creation.js
+++ b/frontend_tests/casper_tests/00-realm-creation.js
@@ -1,7 +1,6 @@
 var common = require('../casper_lib/common.js').common;
 
 var email = 'alice@test.example.com';
-var domain = 'test.example.com';
 var subdomain = 'testsubdomain';
 var organization_name = 'Awesome Organization';
 var REALMS_HAVE_SUBDOMAINS = casper.cli.get('subdomains');
diff --git a/frontend_tests/node_tests/dispatch.js b/frontend_tests/node_tests/dispatch.js
index 928e739649..d6f419edd9 100644
--- a/frontend_tests/node_tests/dispatch.js
+++ b/frontend_tests/node_tests/dispatch.js
@@ -435,7 +435,7 @@ var run = (function () {
 }());
 
 
-run(function (override, capture, args) {
+run(function () {
     // alert_words
     var event = event_fixtures.alert_words;
     dispatch(event);
@@ -443,7 +443,7 @@ run(function (override, capture, args) {
 
 });
 
-run(function (override, capture, args) {
+run(function (override) {
     // default_streams
     var event = event_fixtures.default_streams;
     override('admin', 'update_default_streams_table', noop);
@@ -471,7 +471,7 @@ run(function (override, capture, args) {
 
 });
 
-run(function (override, capture, args) {
+run(function () {
     // pointer
     var event = event_fixtures.pointer;
     global.pointer.furthest_read = 0;
@@ -492,7 +492,7 @@ run(function (override, capture, args) {
 
 });
 
-run(function (override, capture, args) {
+run(function (override) {
     // realm
     function test_realm_boolean(event, parameter_name) {
         page_params[parameter_name] = true;
@@ -565,7 +565,7 @@ run(function (override, capture, args) {
 
 });
 
-run(function (override, capture, args) {
+run(function (override) {
     // realm_filters
     var event = event_fixtures.realm_filters;
     page_params.realm_filters = [];
@@ -684,7 +684,7 @@ run(function (override, capture, args) {
 
 });
 
-run(function (override, capture, args) {
+run(function () {
     // update_display_settings
     var event = event_fixtures.update_display_settings__default_language;
     page_params.default_language = 'en';
diff --git a/frontend_tests/node_tests/people.js b/frontend_tests/node_tests/people.js
index 3a88f81baf..b9379349f4 100644
--- a/frontend_tests/node_tests/people.js
+++ b/frontend_tests/node_tests/people.js
@@ -201,10 +201,6 @@ var _ = global._;
     var search_term = 'a';
     var users = people.get_rest_of_realm();
     var filtered_people = people.filter_people_by_search_terms(users, [search_term]);
-    var expected = [
-        { email: 'athens@example.com', full_name: 'Maria Athens' },
-        { email: 'ashton@example.com', full_name: 'Ashton Smith' },
-    ];
     assert.equal(filtered_people["ashton@example.com"], true);
     assert.equal(filtered_people["athens@example.com"], true);
     assert.equal(_.keys(filtered_people).length, 2);
diff --git a/frontend_tests/node_tests/unread.js b/frontend_tests/node_tests/unread.js
index 38217f4935..bd845f750c 100644
--- a/frontend_tests/node_tests/unread.js
+++ b/frontend_tests/node_tests/unread.js
@@ -123,12 +123,6 @@ var zero_counts = {
 
     // Test defensive code.  Trying to update a message we don't know
     // about should be a no-op.
-    var unknown_message = {
-        id: 18,
-        type: 'stream',
-        stream: 'social',
-        subject: 'lunch',
-    };
     event = {
         subject: 'brunch',
     };
diff --git a/static/js/admin.js b/static/js/admin.js
index 5af021ab6b..01a0f338ae 100644
--- a/static/js/admin.js
+++ b/static/js/admin.js
@@ -2,7 +2,6 @@ var admin = (function () {
 
 var exports = {};
 var all_streams = [];
-var user_row_to_deactivate;
 
 exports.show_or_hide_menu_item = function () {
     var item = $('.admin-menu-item').expectOne();
@@ -41,20 +40,16 @@ exports.update_user_full_name = function (email, new_full_name) {
     user_row.show();
 };
 
-function failed_listing_users(xhr, error) {
+function failed_listing_users(xhr) {
     loading.destroy_indicator($('#subs_page_loading_indicator'));
     ui.report_error(i18n.t("Error listing users or bots"), xhr, $("#administration-status"));
 }
 
-function failed_listing_streams(xhr, error) {
+function failed_listing_streams(xhr) {
     ui.report_error(i18n.t("Error listing streams"), xhr, $("#administration-status"));
 }
 
-function failed_listing_emoji(xhr, error) {
-    ui.report_error(i18n.t("Error listing emoji"), xhr, $("#administration-status"));
-}
-
-function failed_changing_name(xhr, error) {
+function failed_changing_name(xhr) {
     ui.report_error(i18n.t("Error changing name"), xhr, $("#administration-status"));
 }
 
@@ -144,12 +139,11 @@ function make_stream_default(stream_name) {
     var data = {
         stream_name: stream_name
     };
-    var default_streams_table = $("#admin_default_streams_table").expectOne();
 
     channel.put({
         url: '/json/default_streams',
         data: data,
-        error: function (xhr, error_type) {
+        error: function (xhr) {
             if (xhr.status.toString().charAt(0) === "4") {
                 $(".active_stream_row button").closest("td").html(
                     $("<p>").addClass("text-error").text(JSON.parse(xhr.responseText).msg));
@@ -223,7 +217,7 @@ exports.populate_auth_methods = function (auth_methods) {
 };
 
 exports.set_up_deactivate_user_modal = function (row) {
-    $("#do_deactivate_user_button").expectOne().click(function (e) {
+    $("#do_deactivate_user_button").expectOne().click(function () {
         var email = row.find(".email").text();
         if ($("#deactivation_user_modal .email").html() !== email) {
             blueslip.error("User deactivation canceled due to non-matching fields.");
@@ -234,7 +228,7 @@ exports.set_up_deactivate_user_modal = function (row) {
         row.find("button").prop("disabled", true).text("Working…");
         channel.del({
             url: '/json/users/' + email,
-            error: function (xhr, error_type) {
+            error: function (xhr) {
                 if (xhr.status.toString().charAt(0) === "4") {
                     row.find("button").closest("td").html(
                         $("<p>").addClass("text-error").text(JSON.parse(xhr.responseText).msg)
@@ -379,7 +373,7 @@ function _setup_page() {
 
         channel.del({
             url: '/json/default_streams'+ '?' + $.param({stream_name: stream_name}),
-            error: function (xhr, error_type) {
+            error: function (xhr) {
                 if (xhr.status.toString().charAt(0) === "4") {
                     $(".active_default_stream_row button").closest("td").html(
                     $("<p>").addClass("text-error").text(JSON.parse(xhr.responseText).msg));
@@ -404,7 +398,7 @@ function _setup_page() {
     $('.create_default_stream').typeahead({
         items: 5,
         fixed: true,
-        source: function (query) {
+        source: function () {
             return get_non_default_streams_names(all_streams);
         },
         highlight: true,
@@ -419,12 +413,11 @@ function _setup_page() {
 
         var row = $(e.target).closest(".user_row");
 
-        var user_name = row.find('.user_name').text();
         var email = get_email_for_user_row(row);
 
         channel.del({
             url: '/json/bots/' + email,
-            error: function (xhr, error_type) {
+            error: function (xhr) {
                 if (xhr.status.toString().charAt(0) === "4") {
                     row.find("button").closest("td").html(
                         $("<p>").addClass("text-error").text(JSON.parse(xhr.responseText).msg)
@@ -455,7 +448,7 @@ function _setup_page() {
 
         channel.post({
             url: '/json/users/' + email + "/reactivate",
-            error: function (xhr, error_type) {
+            error: function (xhr) {
                 var button = row.find("button");
                 if (xhr.status.toString().charAt(0) === "4") {
                     button.closest("td").html(
@@ -506,7 +499,6 @@ function _setup_page() {
         var create_stream_by_admins_only_status = $("#admin-realm-create-stream-by-admins-only-status").expectOne();
         var message_editing_status = $("#admin-realm-message-editing-status").expectOne();
         var default_language_status = $("#admin-realm-default-language-status").expectOne();
-        var auth_methods_table = $('.admin_auth_methods_table');
         name_status.hide();
         restricted_to_domain_status.hide();
         invite_required_status.hide();
@@ -626,7 +618,7 @@ function _setup_page() {
                     }
                 }
             },
-            error: function (xhr, error) {
+            error: function (xhr) {
                 var reason = $.parseJSON(xhr.responseText).reason;
                 if (reason === "no authentication") {
                     ui.report_error(i18n.t("Failed!"), xhr, authentication_methods_status);
@@ -661,7 +653,7 @@ function _setup_page() {
                 button.removeClass("make-admin");
                 button.text(i18n.t("Remove admin"));
             },
-            error: function (xhr, error) {
+            error: function (xhr) {
                 var status = row.find(".admin-user-status");
                 ui.report_error(i18n.t("Failed!"), xhr, status);
             }
@@ -692,7 +684,7 @@ function _setup_page() {
                 button.removeClass("remove-admin");
                 button.text(i18n.t("Make admin"));
             },
-            error: function (xhr, error) {
+            error: function (xhr) {
                 var status = row.find(".admin-user-status");
                 ui.report_error(i18n.t("Failed!"), xhr, status);
             }
@@ -713,7 +705,7 @@ function _setup_page() {
         user_row.hide();
         form_row.show();
 
-        reset_button.on("click", function (e) {
+        reset_button.on("click", function () {
             form_row.hide();
             user_row.show();
         });
@@ -738,7 +730,7 @@ function _setup_page() {
         });
     });
 
-    $("#do_deactivate_stream_button").click(function (e) {
+    $("#do_deactivate_stream_button").click(function () {
         if ($("#deactivation_stream_modal .stream_name").text() !== $(".active_stream_row").find('.stream_name').text()) {
             blueslip.error("Stream deactivation canceled due to non-matching fields.");
             ui.report_message("Deactivation encountered an error. Please reload and try again.",
@@ -748,7 +740,7 @@ function _setup_page() {
         $(".active_stream_row button").prop("disabled", true).text("Working…");
         channel.del({
             url: '/json/streams/' + encodeURIComponent($(".active_stream_row").find('.stream_name').text()),
-            error: function (xhr, error_type) {
+            error: function (xhr) {
                 if (xhr.status.toString().charAt(0) === "4") {
                     $(".active_stream_row button").closest("td").html(
                         $("<p>").addClass("text-error").text(JSON.parse(xhr.responseText).msg)
@@ -771,7 +763,7 @@ function _setup_page() {
 
         channel.del({
             url: '/json/realm/emoji/' + encodeURIComponent(btn.attr('data-emoji-name')),
-            error: function (xhr, error_type) {
+            error: function (xhr) {
                 if (xhr.status.toString().charAt(0) === "4") {
                     btn.closest("td").html(
                         $("<p>").addClass("text-error").text(JSON.parse(xhr.responseText).msg)
@@ -804,7 +796,7 @@ function _setup_page() {
                 ui.report_success(i18n.t("Custom emoji added!"), emoji_status);
                 $("form.admin-emoji-form input[type='text']").val("");
             },
-            error: function (xhr, error) {
+            error: function (xhr) {
                 $('#admin-emoji-status').hide();
                 var errors = JSON.parse(xhr.responseText).msg;
                 xhr.responseText = JSON.stringify({msg: errors});
@@ -820,7 +812,7 @@ function _setup_page() {
 
         channel.del({
             url: '/json/realm/filters/' + encodeURIComponent(btn.attr('data-filter-id')),
-            error: function (xhr, error_type) {
+            error: function (xhr) {
                 if (xhr.status.toString().charAt(0) === "4") {
                     btn.closest("td").html(
                         $("<p>").addClass("text-error").text($.parseJSON(xhr.responseText).msg)
@@ -857,7 +849,7 @@ function _setup_page() {
                 filter.id = data.id;
                 ui.report_success(i18n.t("Custom filter added!"), filter_status);
             },
-            error: function (xhr, error) {
+            error: function (xhr) {
                 var errors = $.parseJSON(xhr.responseText).errors;
                 if (errors.pattern !== undefined) {
                     xhr.responseText = JSON.stringify({msg: errors.pattern});
diff --git a/static/js/avatar.js b/static/js/avatar.js
index dd36d58bdb..a61f16e926 100644
--- a/static/js/avatar.js
+++ b/static/js/avatar.js
@@ -162,7 +162,7 @@ exports.build_direct_upload_widget = function (
         upload_function
 ) {
 
-    function accept(file) {
+    function accept() {
         input_error.hide();
         upload_function(get_file_input());
     }
diff --git a/static/js/click_handlers.js b/static/js/click_handlers.js
index 5ab818095c..d2c78320bb 100644
--- a/static/js/click_handlers.js
+++ b/static/js/click_handlers.js
@@ -272,10 +272,10 @@ $(function () {
     popovers.register_click_handlers();
     notifications.register_click_handlers();
 
-    $('.logout_button').click(function (e) {
+    $('.logout_button').click(function () {
         $('#logout_form').submit();
     });
-    $('.restart_get_events_button').click(function (e) {
+    $('.restart_get_events_button').click(function () {
         server_events.restart_get_events({dont_block: true});
     });
 
@@ -289,10 +289,10 @@ $(function () {
     );
 
 
-    $('.compose_stream_button').click(function (e) {
+    $('.compose_stream_button').click(function () {
         compose.start('stream');
     });
-    $('.compose_private_button').click(function (e) {
+    $('.compose_private_button').click(function () {
         compose.start('private');
     });
 
@@ -325,7 +325,7 @@ $(function () {
     $("#compose_buttons").click(handle_compose_click);
     $(".compose-content").click(handle_compose_click);
 
-    $("#compose_close").click(function (e) {
+    $("#compose_close").click(function () {
         compose.cancel();
     });
 
@@ -333,7 +333,7 @@ $(function () {
 
     // Keep these 2 feedback bot triggers separate because they have to
     // propagate the event differently.
-    $('.feedback').click(function (e) {
+    $('.feedback').click(function () {
         compose.start('private', {private_message_recipient: 'feedback@zulip.com',
                                   trigger: 'feedback menu item'});
 
@@ -372,10 +372,10 @@ $(function () {
             channel.post({
                 url:      "/accounts/webathena_kerberos_login/",
                 data:     {cred: JSON.stringify(r.session)},
-                success: function (data, success) {
+                success: function () {
                     $("#zephyr-mirror-error").hide();
                 },
-                error: function (data, success) {
+                error: function () {
                     $("#zephyr-mirror-error").show();
                 }
             });
@@ -388,11 +388,11 @@ $(function () {
 
     // BANKRUPTCY
 
-    $(".bankruptcy_button").click(function (e) {
+    $(".bankruptcy_button").click(function () {
         unread.enable();
     });
 
-    $('#yes-bankrupt').click(function (e) {
+    $('#yes-bankrupt').click(function () {
         pointer.fast_forward_pointer();
         $("#yes-bankrupt").hide();
         $("#no-bankrupt").hide();
@@ -432,7 +432,7 @@ $(function () {
             }
         });
 
-        $("#overlay .download").click(function (e) {
+        $("#overlay .download").click(function () {
           this.blur();
         });
     }());
diff --git a/static/js/compose.js b/static/js/compose.js
index ce8937f9b2..de924f5bca 100644
--- a/static/js/compose.js
+++ b/static/js/compose.js
@@ -403,8 +403,6 @@ function compose_error(error_text, bad_input) {
     }
 }
 
-var send_options;
-
 function send_message_ajax(request, success, error) {
     channel.post({
         url: '/json/messages',
diff --git a/static/js/compose_fade.js b/static/js/compose_fade.js
index fb5a502216..e416096a4a 100644
--- a/static/js/compose_fade.js
+++ b/static/js/compose_fade.js
@@ -238,10 +238,10 @@ exports.update_rendered_message_groups = function (message_groups, get_element)
 };
 
 $(function () {
-    $(document).on('peer_subscribe.zulip', function (e) {
+    $(document).on('peer_subscribe.zulip', function () {
         exports.update_faded_users();
     });
-    $(document).on('peer_unsubscribe.zulip', function (e) {
+    $(document).on('peer_unsubscribe.zulip', function () {
         exports.update_faded_users();
     });
 });
diff --git a/static/js/composebox_typeahead.js b/static/js/composebox_typeahead.js
index fe876b5463..436e7e1cde 100644
--- a/static/js/composebox_typeahead.js
+++ b/static/js/composebox_typeahead.js
@@ -165,7 +165,7 @@ function select_on_focus(field_id) {
     // conditions in Chrome so we need to protect against infinite
     // recursion.
     var in_handler = false;
-    $("#" + field_id).focus(function (e) {
+    $("#" + field_id).focus(function () {
         if (in_handler) {
             return;
         }
@@ -378,7 +378,7 @@ exports.initialize = function () {
 
     // limit number of items so the list doesn't fall off the screen
     $( "#stream" ).typeahead({
-        source: function (query, process) {
+        source: function () {
             return stream_data.subscribed_streams();
         },
         items: 3,
@@ -396,7 +396,7 @@ exports.initialize = function () {
     });
 
     $( "#subject" ).typeahead({
-        source: function (query, process) {
+        source: function () {
             var stream_name = $("#stream").val();
             return exports.topics_seen_for(stream_name);
         },
@@ -450,7 +450,7 @@ exports.initialize = function () {
 
     exports.initialize_compose_typeahead("#new_message_content", {mention: true, emoji: true, stream: true});
 
-    $( "#private_message_recipient" ).blur(function (event) {
+    $( "#private_message_recipient" ).blur(function () {
         var val = $(this).val();
         var recipients = exports.get_cleaned_pm_recipients(val);
         $(this).val(recipients.join(", "));
diff --git a/static/js/condense.js b/static/js/condense.js
index aa63e003da..481133500b 100644
--- a/static/js/condense.js
+++ b/static/js/condense.js
@@ -140,7 +140,7 @@ exports.condense_and_collapse = function (elems) {
 };
 
 $(function () {
-    $("#home").on("click", ".message_expander", function (e) {
+    $("#home").on("click", ".message_expander", function () {
         // Expanding a message can mean either uncollapsing or
         // uncondensing it.
         var row = $(this).closest(".message_row");
@@ -158,7 +158,7 @@ $(function () {
         }
     });
 
-    $("#home").on("click", ".message_condenser", function (e) {
+    $("#home").on("click", ".message_condenser", function () {
         var row = $(this).closest(".message_row");
         current_msg_list.get(rows.id(row)).condensed = true;
         condense_row(row);
diff --git a/static/js/copy_and_paste.js b/static/js/copy_and_paste.js
index ece171d843..7b5952fd3c 100644
--- a/static/js/copy_and_paste.js
+++ b/static/js/copy_and_paste.js
@@ -36,7 +36,7 @@ function find_boundary_tr(initial_tr, iterate_row) {
 }
 
 
-function copy_handler(e) {
+function copy_handler() {
     var selection = window.getSelection();
     var i;
     var range;
diff --git a/static/js/custom_markdown.js b/static/js/custom_markdown.js
index 612b80b091..5386ce8bd9 100644
--- a/static/js/custom_markdown.js
+++ b/static/js/custom_markdown.js
@@ -36,7 +36,7 @@ var exports = {};
                 subscriptions: JSON.stringify([stream_name])
             }
         }).then(
-            function (data) {
+            function () {
                 $status_message.hide();
             }, function (xhr) {
                 ui.report_error(i18n.t("Error removing subscription"), xhr, $status_message);
diff --git a/static/js/echo.js b/static/js/echo.js
index 42ba81e324..14a5b65304 100644
--- a/static/js/echo.js
+++ b/static/js/echo.js
@@ -415,7 +415,7 @@ exports.set_realm_filters = function set_realm_filters(realm_filters) {
 
 $(function () {
     function disable_markdown_regex(rules, name) {
-        rules[name] = {exec: function (_) {
+        rules[name] = {exec: function () {
                 return false;
             }
         };
@@ -533,7 +533,7 @@ $(document).on('socket_loaded_requests.zulip', function (event, data) {
     var msgs_to_insert = [];
 
     var next_local_id = get_next_local_id();
-    _.each(data.requests, function (socket_msg, key) {
+    _.each(data.requests, function (socket_msg) {
         var msg = socket_msg.msg;
         // Check for any message objects, then insert them locally
         if (msg.stream === undefined || msg.local_id === undefined) {
diff --git a/static/js/invite.js b/static/js/invite.js
index f9882dd0fb..cbbd8d7826 100644
--- a/static/js/invite.js
+++ b/static/js/invite.js
@@ -53,7 +53,7 @@ exports.initialize = function () {
 
     $("#invite_user_form").ajaxForm({
         dataType: 'json',
-        beforeSubmit: function (arr, $form, options) {
+        beforeSubmit: function () {
             reset_error_messages();
             // TODO: You could alternatively parse the textarea here, and return errors to
             // the user if they don't match certain constraints (i.e. not real email addresses,
@@ -63,7 +63,7 @@ exports.initialize = function () {
             $('#submit-invitation').button('loading');
             return true;
         },
-        success: function (resp, statusText, xhr, form) {
+        success: function () {
             $('#submit-invitation').button('reset');
             invite_status.text(i18n.t('User invited successfully.', {count: (invitee_emails.val().match(/@/g) || [] ).length}))
                           .addClass('alert-success')
@@ -77,7 +77,7 @@ exports.initialize = function () {
             }
 
         },
-        error: function (xhr, error_type, xhn) {
+        error: function (xhr) {
             $('#submit-invitation').button('reset');
             var arr = JSON.parse(xhr.responseText);
             if (arr.errors === undefined) {
diff --git a/static/js/message_edit.js b/static/js/message_edit.js
index 364b1c2fb2..731fa0f0c8 100644
--- a/static/js/message_edit.js
+++ b/static/js/message_edit.js
@@ -105,12 +105,12 @@ exports.save = function (row, from_topic_edited_only) {
     channel.post({
         url: '/json/update_message',
         data: request,
-        success: function (data) {
+        success: function () {
             if (msg_list === current_msg_list) {
                 row.find(".edit_error").text("Message successfully edited!").removeClass("alert-error").addClass("alert-success").show();
             }
         },
-        error: function (xhr, error_type, xhn) {
+        error: function (xhr) {
             if (msg_list === current_msg_list) {
                 var message = channel.xhr_error_message("Error saving edit", xhr);
                 row.find(".edit_error").text(message).show();
@@ -355,7 +355,7 @@ exports.maybe_show_edit = function (row, id) {
     }
 };
 
-$(document).on('narrow_deactivated.zulip', function (event) {
+$(document).on('narrow_deactivated.zulip', function () {
     _.each(currently_editing_messages, function (elem, idx) {
         if (current_msg_list.get(idx) !== undefined) {
             var row = current_msg_list.get_row(idx);
diff --git a/static/js/message_flags.js b/static/js/message_flags.js
index 6b78a135e8..4909c0908b 100644
--- a/static/js/message_flags.js
+++ b/static/js/message_flags.js
@@ -41,7 +41,7 @@ function batched_updater(flag, op, immediate) {
         start = _.debounce(server_request, 1000);
     }
 
-    on_success = function on_success(data, status, jqXHR) {
+    on_success = function on_success(data) {
         if (data ===  undefined || data.messages === undefined) {
             return;
         }
diff --git a/static/js/message_list.js b/static/js/message_list.js
index e480018521..0e93fa6c6b 100644
--- a/static/js/message_list.js
+++ b/static/js/message_list.js
@@ -634,7 +634,7 @@ exports.all = new exports.MessageList(
 // doing something.  Be careful, though, if you try to capture
 // mousemove, then you will have to contend with the autoscroll
 // itself generating mousemove events.
-$(document).on('message_selected.zulip zuliphashchange.zulip mousewheel', function (event) {
+$(document).on('message_selected.zulip zuliphashchange.zulip mousewheel', function () {
     viewport.stop_auto_scrolling();
 });
 
diff --git a/static/js/message_list_view.js b/static/js/message_list_view.js
index bc7f47d2b1..88ebaf5314 100644
--- a/static/js/message_list_view.js
+++ b/static/js/message_list_view.js
@@ -130,8 +130,7 @@ MessageListView.prototype = {
         }
     },
 
-    build_message_groups: function MessageListView__build_message_groups(message_containers,
-                                                                         message_id_prefix) {
+    build_message_groups: function MessageListView__build_message_groups(message_containers) {
         function start_group() {
             return {
                 message_containers: [],
@@ -399,10 +398,7 @@ MessageListView.prototype = {
         // we we record if last_message_was_selected before updating the table
         var last_message_was_selected = rows.id(rows.last_visible()) === list.selected_id();
         var orig_scrolltop_offset;
-        var last_message_id;
         var message_containers;
-        var first_msg;
-        var last_msg;
 
         var self = this;
 
@@ -582,7 +578,6 @@ MessageListView.prototype = {
         // scroll up without moving the pointer out of the viewport, do so, by
         // up to the amount taken up by the new message.
         var new_messages_height = 0;
-        var distance_to_last_message_sent_by_me = 0;
         var id_of_last_message_sent_by_us = -1;
 
         // C++ iterators would have made this less painful
@@ -593,14 +588,12 @@ MessageListView.prototype = {
                 new_messages_height += elem.height();
                 // starting from the last message, ignore message heights that weren't sent by me.
                 if (id_of_last_message_sent_by_us > -1) {
-                    distance_to_last_message_sent_by_me += elem.height();
                     return;
                 }
                 var row_id = rows.id(elem);
                 // check for `row_id` NaN in case we're looking at a date row or bookend row
                 if (row_id > -1 &&
                     util.is_current_user(this.get_message(row_id).sender_email)) {
-                    distance_to_last_message_sent_by_me += elem.height();
                     id_of_last_message_sent_by_us = rows.id(elem);
                 }
             }
@@ -803,13 +796,6 @@ MessageListView.prototype = {
     rerender_messages: function MessageListView__rerender_messages(messages) {
         var self = this;
 
-        // Only re-render the messages that are in this narrow
-        var own_messages = _.map(messages, function (message) {
-            return self.list.get(message.id);
-        });
-        own_messages = _.reject(own_messages, function (message) {
-            return message === undefined;
-        });
         // Convert messages to list messages
         var message_containers = _.map(messages, function (message) {
             return self.message_containers[message.id];
@@ -868,13 +854,10 @@ MessageListView.prototype = {
         }
     },
 
-    rerender_the_whole_thing: function MessageListView__rerender_the_whole_thing(messages) {
+    rerender_the_whole_thing: function MessageListView__rerender_the_whole_thing() {
         // TODO: Figure out if we can unify this with this.list.rerender().
-
         this.clear_rendering_state(true);
-
         this.update_render_window(this.list.selected_idx(), false);
-
         this.render(this.list.all_messages().slice(this._render_win_start, this._render_win_end), 'bottom');
     },
 
diff --git a/static/js/message_store.js b/static/js/message_store.js
index 14f53212fb..561295b483 100644
--- a/static/js/message_store.js
+++ b/static/js/message_store.js
@@ -41,7 +41,7 @@ exports.get_private_message_recipient = function (message, attr, fallback_attr)
 };
 
 exports.process_message_for_recent_private_messages =
-    function process_message_for_recent_private_messages(message, remove_message) {
+    function process_message_for_recent_private_messages(message) {
     var current_timestamp = 0;
 
     var user_ids_string = people.emails_strings_to_user_ids_string(message.reply_to);
@@ -219,7 +219,7 @@ function maybe_add_narrowed_messages(messages, msg_list, messages_are_new) {
             notifications.possibly_notify_new_messages_outside_viewport(new_messages);
             notifications.notify_messages_outside_current_search(elsewhere_messages);
         },
-        error: function (xhr) {
+        error: function () {
             // We might want to be more clever here
             setTimeout(function () {
                 if (msg_list === current_msg_list) {
@@ -496,7 +496,7 @@ exports.load_old_messages = function load_old_messages(opts) {
         success: function (data) {
             get_old_messages_success(data, opts);
         },
-        error: function (xhr, error_type, exn) {
+        error: function (xhr) {
             if (opts.msg_list.narrowed && opts.msg_list !== current_msg_list) {
                 // We unnarrowed before getting an error so don't
                 // bother trying again or doing further processing.
diff --git a/static/js/muting_ui.js b/static/js/muting_ui.js
index 820ac2de1d..7e02aff6f6 100644
--- a/static/js/muting_ui.js
+++ b/static/js/muting_ui.js
@@ -17,7 +17,6 @@ exports.rerender = function () {
 };
 
 exports.notify_with_undo_option = (function () {
-    var event_added = false;
     var meta = {
         stream: null,
         topic: null,
@@ -26,12 +25,12 @@ exports.notify_with_undo_option = (function () {
         $mute: null
     };
     var animate = {
-        fadeOut: function ($mute) {
+        fadeOut: function () {
             if (meta.$mute) {
                 meta.$mute.fadeOut(500).removeClass("show");
             }
         },
-        fadeIn: function ($mute) {
+        fadeIn: function () {
             if (meta.$mute) {
                 meta.$mute.fadeIn(500).addClass("show");
             }
diff --git a/static/js/notifications.js b/static/js/notifications.js
index c4cac33e84..8d330563b4 100644
--- a/static/js/notifications.js
+++ b/static/js/notifications.js
@@ -9,7 +9,6 @@ var notice_memory = {};
 var window_has_focus = document.hasFocus && document.hasFocus();
 
 var asked_permission_already = false;
-var names;
 var supports_sound;
 
 var unread_pms_favicon = '/static/images/favicon/favicon-pms.png';
diff --git a/static/js/popovers.js b/static/js/popovers.js
index 5c4623e866..41ff2217ff 100644
--- a/static/js/popovers.js
+++ b/static/js/popovers.js
@@ -521,7 +521,6 @@ exports.register_click_handlers = function () {
 
         var stream = $(elt).parents('li').attr('data-name');
 
-        var ypos = $(elt).offset().top - viewport.scrollTop();
         $(elt).popover({
             content:   templates.render('stream_sidebar_actions', {stream: stream_data.get_sub(stream)}),
             trigger:   "manual",
@@ -566,7 +565,7 @@ exports.register_click_handlers = function () {
                 $(e.target).hide();
             });
 
-            $('.streams_popover').on('click', 'a.sp-cancel', function (e) {
+            $('.streams_popover').on('click', 'a.sp-cancel', function () {
                 popovers.hide_stream_sidebar_popover();
             });
         });
diff --git a/static/js/referral.js b/static/js/referral.js
index 9b3e9b508b..87ba7737ff 100644
--- a/static/js/referral.js
+++ b/static/js/referral.js
@@ -93,7 +93,7 @@ $(function () {
         }
     });
 
-    $("#referral-form input").on('blur', function (e) {
+    $("#referral-form input").on('blur', function () {
         if ($("#referral-form input").val() === '') {
             validator.resetForm();
             resize.resize_page_components();
diff --git a/static/js/resize.js b/static/js/resize.js
index e9d7212917..fe7f6e1450 100644
--- a/static/js/resize.js
+++ b/static/js/resize.js
@@ -15,8 +15,6 @@ function confine_to_range(lo, val, hi) {
 }
 
 function size_blocks(blocks, usable_height) {
-    var n = blocks.length;
-
     var sum_height = 0;
     _.each(blocks, function (block) {
         sum_height += block.real_height;
@@ -183,15 +181,6 @@ exports.resize_stream_filters_container = function (h) {
 };
 
 exports.resize_page_components = function () {
-    var composebox = $("#compose");
-    var floating_recipient_bar = $("#floating_recipient_bar");
-    var desired_width;
-    if (ui.home_tab_obscured() === 'other_tab') {
-        desired_width = $("div.tab-pane.active").outerWidth();
-    } else {
-        desired_width = $("#main_div").outerWidth();
-    }
-
     var h;
     var sidebar;
 
@@ -238,7 +227,7 @@ exports.resize_page_components = function () {
 
 var _old_width = $(window).width();
 
-exports.handler = function (e) {
+exports.handler = function () {
     var new_width = $(window).width();
 
     if (new_width !== _old_width) {
diff --git a/static/js/search.js b/static/js/search.js
index 6db85ab53a..cffe305c60 100644
--- a/static/js/search.js
+++ b/static/js/search.js
@@ -60,7 +60,7 @@ exports.initialize = function () {
             var obj = search_object[item];
             return obj.description;
         },
-        matcher: function (item) {
+        matcher: function () {
             return true;
         },
         updater: narrow_or_search_for_term,
diff --git a/static/js/server_events.js b/static/js/server_events.js
index a78d9d7d47..fc553261d9 100644
--- a/static/js/server_events.js
+++ b/static/js/server_events.js
@@ -356,7 +356,7 @@ function get_events(options) {
             }
             get_events_timeout = setTimeout(get_events, 0);
         },
-        error: function (xhr, error_type, exn) {
+        error: function (xhr, error_type) {
             try {
                 get_events_xhr = undefined;
                 // If we are old enough to have messages outside of the
@@ -458,7 +458,7 @@ exports.cleanup_event_queue = function cleanup_event_queue() {
     });
 };
 
-window.addEventListener("beforeunload", function (event) {
+window.addEventListener("beforeunload", function () {
     exports.cleanup_event_queue();
 });
 
diff --git a/static/js/settings.js b/static/js/settings.js
index d6cc08bc32..f6cbed4a8b 100644
--- a/static/js/settings.js
+++ b/static/js/settings.js
@@ -187,7 +187,7 @@ function _setup_page() {
 
     clear_password_change();
 
-    $('#api_key_button').click(function (e) {
+    $('#api_key_button').click(function () {
         if (page_params.password_auth_enabled !== false) {
             $("#get_api_key_box").show();
         } else {
@@ -237,7 +237,7 @@ function _setup_page() {
 
     $("form.your-account-settings").ajaxForm({
         dataType: 'json', // This seems to be ignored. We still get back an xhr.
-        beforeSubmit: function (arr, form, options) {
+        beforeSubmit: function () {
             if (page_params.password_auth_enabled !== false) {
                 // FIXME: Check that the two password fields match
                 // FIXME: Use the same jQuery validation plugin as the signup form?
@@ -258,21 +258,20 @@ function _setup_page() {
             }
             return true;
         },
-        success: function (resp, statusText, xhr, form) {
+        success: function () {
             settings_change_success("Updated settings!");
         },
-        error: function (xhr, error_type, xhn) {
+        error: function (xhr) {
             settings_change_error("Error changing settings", xhr);
         },
-        complete: function (xhr, statusText) {
+        complete: function () {
             // Whether successful or not, clear the password boxes.
             // TODO: Clear these earlier, while the request is still pending.
             clear_password_change();
         }
     });
 
-    function update_notification_settings_success(resp, statusText, xhr, form) {
-        var message = "Updated notification settings!";
+    function update_notification_settings_success(resp, statusText, xhr) {
         var result = JSON.parse(xhr.responseText);
         var notify_settings_status = $('#notify-settings-status').expectOne();
 
@@ -318,7 +317,7 @@ function _setup_page() {
         ui.report_success(i18n.t("Updated notification settings!"), notify_settings_status);
     }
 
-    function update_notification_settings_error(xhr, error_type, xhn) {
+    function update_notification_settings_error(xhr) {
         ui.report_error(i18n.t("Error changing settings"), xhr, $('#notify-settings-status').expectOne());
     }
 
@@ -376,22 +375,22 @@ function _setup_page() {
         var control_group = notification_checkbox.closest(".control-group");
         var checkbox_status = notification_checkbox.is(":checked");
         control_group.find(".propagate_stream_notifications_change").html(html);
-        control_group.find(".yes_propagate_notifications").on("click", function (e) {
+        control_group.find(".yes_propagate_notifications").on("click", function () {
             propagate_setting_function(checkbox_status);
             control_group.find(".propagate_stream_notifications_change").empty();
         });
-        control_group.find(".no_propagate_notifications").on("click", function (e) {
+        control_group.find(".no_propagate_notifications").on("click", function () {
             control_group.find(".propagate_stream_notifications_change").empty();
         });
     }
 
-    $("#enable_stream_desktop_notifications").on("click", function (e) {
+    $("#enable_stream_desktop_notifications").on("click", function () {
         var notification_checkbox = $("#enable_stream_desktop_notifications");
         maybe_bulk_update_stream_notification_setting(notification_checkbox,
                                                       update_desktop_notification_setting);
     });
 
-    $("#enable_stream_sounds").on("click", function (e) {
+    $("#enable_stream_sounds").on("click", function () {
         var notification_checkbox = $("#enable_stream_sounds");
         maybe_bulk_update_stream_notification_setting(notification_checkbox,
                                                       update_audible_notification_setting);
@@ -411,11 +410,11 @@ function _setup_page() {
         channel.patch({
             url: '/json/left_side_userlist',
             data: data,
-            success: function (resp, statusText, xhr, form) {
+            success: function () {
                 ui.report_success(i18n.t("User list will appear on the __side__ hand side! You will need to reload the window for your changes to take effect.", context),
                                   $('#display-settings-status').expectOne());
             },
-            error: function (xhr, error_type, xhn) {
+            error: function (xhr) {
                 ui.report_error(i18n.t("Error updating user list placement setting"), xhr, $('#display-settings-status').expectOne());
             }
         });
@@ -435,11 +434,11 @@ function _setup_page() {
         channel.patch({
             url: '/json/time_setting',
             data: data,
-            success: function (resp, statusText, xhr, form) {
+            success: function () {
                 ui.report_success(i18n.t("Time will be displayed in the __format__-hour format!  You will need to reload the window for your changes to take effect", context),
                                   $('#display-settings-status').expectOne());
             },
-            error: function (xhr, error_type, xhn) {
+            error: function (xhr) {
                 ui.report_error(i18n.t("Error updating time format setting"), xhr, $('#display-settings-status').expectOne());
             }
         });
@@ -464,11 +463,11 @@ function _setup_page() {
         channel.patch({
             url: '/json/language_setting',
             data: data,
-            success: function (resp, statusText, xhr, form) {
+            success: function () {
                 ui.report_success(i18n.t("__lang__ is now the default language!  You will need to reload the window for your changes to take effect", context),
                                   $('#display-settings-status').expectOne());
             },
-            error: function (xhr, error_type, xhn) {
+            error: function (xhr) {
                 ui.report_error(i18n.t("Error updating default language setting"), xhr, $('#display-settings-status').expectOne());
             }
         });
@@ -486,14 +485,14 @@ function _setup_page() {
         $("#deactivate_self_modal").modal("show");
     });
 
-    $("#do_deactivate_self_button").on('click',function (e) {
+    $("#do_deactivate_self_button").on('click',function () {
         $("#deactivate_self_modal").modal("hide");
         channel.del({
             url: '/json/users/me',
             success: function () {
                 window.location.href = "/login";
             },
-            error: function (xhr, error_type) {
+            error: function (xhr) {
                 ui.report_error(i18n.t("Error deactivating account"), xhr, $('#settings-status').expectOne());
             }
         });
@@ -503,8 +502,7 @@ function _setup_page() {
     $("#show_api_key_box").hide();
     $("#get_api_key_box form").ajaxForm({
         dataType: 'json', // This seems to be ignored. We still get back an xhr.
-        success: function (resp, statusText, xhr, form) {
-            var message = "Updated settings!";
+        success: function (resp, statusText, xhr) {
             var result = JSON.parse(xhr.responseText);
             var settings_status = $('#settings-status').expectOne();
 
@@ -514,7 +512,7 @@ function _setup_page() {
             $("#get_api_key_box").hide();
             settings_status.hide();
         },
-        error: function (xhr, error_type, xhn) {
+        error: function (xhr) {
             ui.report_error(i18n.t("Error getting API key"), xhr, $('#settings-status').expectOne());
             $("#show_api_key_box").hide();
             $("#get_api_key_box").show();
@@ -595,17 +593,17 @@ function _setup_page() {
                 cache: false,
                 processData: false,
                 contentType: false,
-                success: function (data) {
+                success: function () {
                     $('#bot_table_error').hide();
                     $('#create_bot_name').val('');
                     $('#create_bot_short_name').val('');
                     $('#create_bot_button').show();
                     create_avatar_widget.clear();
                 },
-                error: function (xhr, error_type, exn) {
+                error: function (xhr) {
                     $('#bot_table_error').text(JSON.parse(xhr.responseText).msg).show();
                 },
-                complete: function (xhr, status) {
+                complete: function () {
                     $('#create_bot_button').val('Create bot').prop('disabled', false);
                 }
             });
@@ -678,7 +676,7 @@ function _setup_page() {
 
         form.validate({
             errorClass: 'text-error',
-            success: function (label) {
+            success: function () {
                 errors.hide();
             },
             submitHandler: function () {
@@ -720,7 +718,7 @@ function _setup_page() {
                             image.find('img').attr('src', data.avatar_url+'&v='+image_version.toString());
                         }
                     },
-                    error: function (xhr, error_type, exn) {
+                    error: function (xhr) {
                         loading.destroy_indicator(spinner);
                         edit_button.show();
                         errors.text(JSON.parse(xhr.responseText).msg).show();
@@ -749,7 +747,7 @@ function _setup_page() {
         ));
     });
 
-    $("#show_api_key_box").on("click", "button.regenerate_api_key", function (e) {
+    $("#show_api_key_box").on("click", "button.regenerate_api_key", function () {
         channel.post({
             url: '/json/users/me/api_key/regenerate',
             idempotent: true,
@@ -762,9 +760,7 @@ function _setup_page() {
         });
     });
 
-    $("#ui-settings").on("click", "input[name='change_settings']", function (e) {
-        e.preventDefault();
-
+    $("#ui-settings").on("click", "input[name='change_settings']", function () {
         var labs_updates = {};
         _.each(["autoscroll_forever", "default_desktop_notifications"],
             function (setting) {
@@ -774,7 +770,7 @@ function _setup_page() {
         channel.post({
             url: '/json/ui_settings/change',
             data: labs_updates,
-            success: function (resp, statusText, xhr, form) {
+            success: function (resp, statusText, xhr) {
                 var message = i18n.t("Updated __product_name__ Labs settings!", page_params);
                 var result = JSON.parse(xhr.responseText);
                 var ui_settings_status = $('#ui-settings-status').expectOne();
@@ -786,7 +782,7 @@ function _setup_page() {
 
                 ui.report_success(message, ui_settings_status);
             },
-            error: function (xhr, error_type, xhn) {
+            error: function (xhr) {
                 ui.report_error(i18n.t("Error changing settings"), xhr, $('#ui-settings-status').expectOne());
             }
         });
diff --git a/static/js/signup.js b/static/js/signup.js
index 5123a74143..f22b3a2dc3 100644
--- a/static/js/signup.js
+++ b/static/js/signup.js
@@ -2,7 +2,7 @@ $(function () {
     // NB: this file is included on multiple pages.  In each context,
     // some of the jQuery selectors below will return empty lists.
 
-    $.validator.addMethod('password_strength', function (value, element) {
+    $.validator.addMethod('password_strength', function (value) {
         return password_quality(value);
     }, 'Password is weak.');
 
@@ -38,7 +38,7 @@ $(function () {
 
     $("#send_confirm").validate({
         errorElement: "p",
-        errorPlacement: function (error, element) {
+        errorPlacement: function (error) {
             $('#errors').empty();
             error.appendTo("#errors")
                  .addClass("text-error");
diff --git a/static/js/stream_list.js b/static/js/stream_list.js
index a19b6064fb..13148ea971 100644
--- a/static/js/stream_list.js
+++ b/static/js/stream_list.js
@@ -370,9 +370,8 @@ exports.update_dom_with_unread_counts = function (counts) {
                                       counts.mentioned_message_count);
 };
 
-exports.rename_stream = function (sub, new_name) {
-    // TODO: we don't actually need new_name, since the sub
-    //       will have been updated
+exports.rename_stream = function (sub) {
+    // The sub object is expected to already have the updated name
     build_stream_sidebar_row(sub);
     exports.build_stream_list(); // big hammer
 };
diff --git a/static/js/subs.js b/static/js/subs.js
index 73338804fd..63f7c5b62b 100644
--- a/static/js/subs.js
+++ b/static/js/subs.js
@@ -232,7 +232,6 @@ function stream_audible_notifications_clicked(e) {
 function stream_pin_clicked(e) {
     var stream = get_stream_name(e.target);
 
-    var sub = stream_data.get_sub(stream);
     exports.toggle_pin_to_top_stream(stream);
 }
 
@@ -336,7 +335,7 @@ function show_subscription_settings(sub_row) {
                 list.append(elem);
             });
         },
-        error: function (xhr) {
+        error: function () {
             loading.destroy_indicator(indicator_elem);
             error_elem.removeClass("hide").text("Could not fetch subscriber list");
         }
@@ -365,19 +364,8 @@ function show_subscription_settings(sub_row) {
     });
 
     var colorpicker = sub_settings.find('.colorpicker');
-
     var color = stream_data.get_color(sub.name);
     stream_color.set_colorpicker_color(colorpicker, color);
-
-    // To figure out the worst case for an expanded row's height, we do some math:
-    // .subscriber_list_container max-height,
-    // .subscriber_list_settings,
-    // .regular_subscription_settings
-    // .subscription_header line-height,
-    // .subscription_header padding
-    var expanded_row_size = 200 + 30 + 100 + 30 + 5;
-    var cover = sub_row.offset().top + expanded_row_size -
-        viewport.height() + viewport.scrollTop();
 }
 
 exports.show_settings_for = function (stream_name) {
@@ -692,7 +680,7 @@ function ajaxSubscribe(stream) {
     return channel.post({
         url: "/json/users/me/subscriptions",
         data: {subscriptions: JSON.stringify([{name: stream}]) },
-        success: function (resp, statusText, xhr, form) {
+        success: function (resp, statusText, xhr) {
             $("#create_stream_name").val("");
 
             actually_filter_streams();
@@ -717,9 +705,7 @@ function ajaxUnsubscribe(stream) {
     return channel.post({
         url: "/json/subscriptions/remove",
         data: {subscriptions: JSON.stringify([stream]) },
-        success: function (resp, statusText, xhr, form) {
-            var name;
-            var res = JSON.parse(xhr.responseText);
+        success: function () {
             $("#subscriptions-status").hide();
             // The rest of the work is done via the unsubscribe event we will get
         },
@@ -739,7 +725,7 @@ function ajaxSubscribeForCreation(stream, description, principals, invite_only,
                invite_only: JSON.stringify(invite_only),
                announce: JSON.stringify(announce)
         },
-        success: function (data) {
+        success: function () {
             $("#create_stream_name").val("");
             $("#create_stream_description").val("");
             $("#subscriptions-status").hide();
@@ -808,7 +794,6 @@ exports.remove_user_from_stream = function (user_email, stream_name, success, fa
 };
 
 $(function () {
-    var i;
 
     stream_data.initialize_from_page_params();
     stream_list.create_initial_sidebar_rows();
@@ -963,11 +948,11 @@ $(function () {
         $(e.target).removeClass("btn-danger").text(i18n.t("Subscribed"));
     });
 
-    $(".subscriptions").on("click", "#close-subscriptions-status", function (e) {
+    $(".subscriptions").on("click", "#close-subscriptions-status", function () {
         $("#subscriptions-status").hide();
     });
 
-    $("#subscriptions_table").on("click", ".email-address", function (e) {
+    $("#subscriptions_table").on("click", ".email-address", function () {
         selectText(this);
     });
 
@@ -1077,7 +1062,7 @@ $(function () {
             }
         }
 
-        function invite_failure(xhr) {
+        function invite_failure() {
             warning_elem.addClass("hide");
             error_elem.removeClass("hide").text("Could not add user to this stream");
         }
@@ -1144,7 +1129,7 @@ $(function () {
             }
         }
 
-        function removal_failure(xhr) {
+        function removal_failure() {
             warning_elem.addClass("hide");
             error_elem.removeClass("hide").text("Could not remove user from this stream");
         }
@@ -1167,7 +1152,7 @@ $(function () {
             // Stream names might contain unsafe characters so we must encode it first.
             url: "/json/streams/" + encodeURIComponent(sub.name),
             data: {new_name: JSON.stringify(new_name)},
-            success: function (data) {
+            success: function () {
                 new_name_box.val('');
                 ui.report_success(i18n.t("The stream has been renamed!"), $("#subscriptions-status "),
                                   'subscriptions-status');
@@ -1181,8 +1166,6 @@ $(function () {
 
     $('#subscriptions_table').on('submit', '.change-stream-description form', function (e) {
         e.preventDefault();
-        var form = $(e.target);
-
         var sub_settings = $(e.target).closest('.subscription_settings');
         var stream_name = get_stream_name(sub_settings);
         var description = sub_settings.find('input[name="description"]').val();
@@ -1247,7 +1230,7 @@ $(function () {
         channel.post({
             url: url,
             data: data,
-            success: function (data) {
+            success: function () {
                 sub = stream_data.get_sub_by_id(stream_id);
                 var stream_settings = settings_for_sub(sub);
                 var sub_row = $(".stream-row[data-stream-id='" + stream_id + "']");
diff --git a/static/js/tab_bar.js b/static/js/tab_bar.js
index d5578ab4f9..76a2372d18 100644
--- a/static/js/tab_bar.js
+++ b/static/js/tab_bar.js
@@ -37,7 +37,6 @@ function make_tab_data() {
     if (narrow.active() && narrow.operators().length > 0) {
         var stream;
         var ops = narrow.operators();
-        var hash = hashchange.operators_to_hash(ops);
         // Second breadcrumb item
         var hashed = hashchange.operators_to_hash(ops.slice(0, 1));
         if (filter.has_operator("stream")) {
@@ -150,10 +149,10 @@ function build_tab_bar() {
 }
 
 $(function () {
-    $(document).on('narrow_activated.zulip', function (event) {
+    $(document).on('narrow_activated.zulip', function () {
         build_tab_bar();
     });
-    $(document).on('narrow_deactivated.zulip', function (event) {
+    $(document).on('narrow_deactivated.zulip', function () {
         build_tab_bar();
     });
 
diff --git a/static/js/typeahead_helper.js b/static/js/typeahead_helper.js
index f639fd6ab7..829deddee9 100644
--- a/static/js/typeahead_helper.js
+++ b/static/js/typeahead_helper.js
@@ -131,10 +131,6 @@ exports.sort_by_pms = function (objs) {
     return objs;
 };
 
-function identity(item) {
-    return item;
-}
-
 exports.sort_recipients = function (matches, query) {
     var name_results =  prefix_sort(query, matches, function (x) { return x.full_name; });
     var email_results = prefix_sort(query, name_results.rest, function (x) { return x.email; });
diff --git a/static/js/ui.js b/static/js/ui.js
index a470479d5c..2b378e4fbf 100644
--- a/static/js/ui.js
+++ b/static/js/ui.js
@@ -98,11 +98,9 @@ exports.replace_emoji_with_text = function (element) {
 
 var current_message_hover;
 function message_unhover() {
-    var message;
     if (current_message_hover === undefined) {
         return;
     }
-    message = current_msg_list.get(rows.id(current_message_hover));
     current_message_hover.find('span.edit_content').html("");
     current_message_hover.removeClass('message_hovered');
     current_message_hover = undefined;
@@ -172,15 +170,6 @@ exports.report_success = function (response, status_box, type) {
     ui.report_message(response, status_box, 'alert-success', type);
 };
 
-function need_skinny_mode() {
-    if (window.matchMedia !== undefined) {
-        return window.matchMedia("(max-width: 767px)").matches;
-    }
-    // IE<10 doesn't support window.matchMedia, so do this
-    // as best we can without it.
-    return window.innerWidth <= 767;
-}
-
 function update_message_in_all_views(message_id, callback) {
     _.each([message_list.all, home_msg_list, message_list.narrowed], function (list) {
         if (list === undefined) {
@@ -315,7 +304,7 @@ exports.lightbox_photo = function (image, user) {
     $(".image-actions .open, .image-actions .download").attr("href", url);
 };
 
-exports.exit_lightbox_photo = function (image) {
+exports.exit_lightbox_photo = function () {
     $("#overlay").removeClass("show");
     $(".player-container iframe").remove();
     document.activeElement.blur();
@@ -451,30 +440,30 @@ $(function () {
         $("#navbar-buttons").addClass("right-userlist");
     }
 
-    $("#main_div").on("mouseover", ".message_row", function (e) {
+    $("#main_div").on("mouseover", ".message_row", function () {
         var row = $(this).closest(".message_row");
         message_hover(row);
     });
 
-    $("#main_div").on("mouseleave", ".message_row", function (e) {
+    $("#main_div").on("mouseleave", ".message_row", function () {
         message_unhover();
     });
 
-    $("#main_div").on("mouseover", ".message_sender", function (e) {
+    $("#main_div").on("mouseover", ".message_sender", function () {
         var row = $(this).closest(".message_row");
         row.addClass("sender_name_hovered");
     });
 
-    $("#main_div").on("mouseout", ".message_sender", function (e) {
+    $("#main_div").on("mouseout", ".message_sender", function () {
         var row = $(this).closest(".message_row");
         row.removeClass("sender_name_hovered");
     });
 
-    $("#subscriptions_table").on("mouseover", ".subscription_header", function (e) {
+    $("#subscriptions_table").on("mouseover", ".subscription_header", function () {
         $(this).addClass("active");
     });
 
-    $("#subscriptions_table").on("mouseout", ".subscription_header", function (e) {
+    $("#subscriptions_table").on("mouseout", ".subscription_header", function () {
         $(this).removeClass("active");
     });
 
@@ -574,8 +563,6 @@ $(function () {
 });
 
 
-var scroll_start_message;
-
 function scroll_finished() {
     actively_scrolling = false;
 
@@ -613,7 +600,7 @@ function scroll_finish() {
 var saved_compose_cursor = 0;
 
 $(function () {
-    viewport.message_pane.scroll($.throttle(50, function (e) {
+    viewport.message_pane.scroll($.throttle(50, function () {
         unread.process_visible();
         scroll_finish();
     }));
diff --git a/static/js/unread.js b/static/js/unread.js
index 2091014221..6c7abf9c3f 100644
--- a/static/js/unread.js
+++ b/static/js/unread.js
@@ -327,7 +327,7 @@ exports.mark_message_as_read = function mark_message_as_read(message, options) {
 
 // If we ever materially change the algorithm for this function, we
 // may need to update notifications.received_messages as well.
-exports.process_visible = function process_visible(update_cursor) {
+exports.process_visible = function process_visible() {
     if (! notifications.window_has_focus()) {
         return;
     }