stream_id: Replace empty string with undefined.

This commit also limits `stream_bar.decorate` to only
be able to be called for stream messages, since it's
an undefined string_id is no longer a sign that
you're dealing with a DM.

tools/test-js-with-node

@@ -218,7 +218,6 @@ EXEMPT_FILES = make_set(
         "web/src/spectators.ts",
         "web/src/spoilers.ts",
         "web/src/starred_messages_ui.js",
-        "web/src/stream_bar.js",
         "web/src/stream_color.js",
         "web/src/stream_color_events.js",
         "web/src/stream_create.js",

web/src/compose.js

@@ -68,7 +68,7 @@ export function create_message_object() {
         content: compose_state.message_content(),
         sender_id: page_params.user_id,
         queue_id: page_params.queue_id,
-        stream_id: "",
+        stream_id: undefined,
     };
     message.topic = "";
 

web/src/compose_actions.js

@@ -111,10 +111,12 @@ export function complete_starting_tasks(msg_type, opts) {
 
     maybe_scroll_up_selected_message();
     compose_fade.start_compose(msg_type);
-    stream_bar.decorate(
+    if (msg_type === "stream") {
-        opts.stream_id,
+        stream_bar.decorate(
-        $("#stream_message_recipient_topic .message_header_stream"),
+            opts.stream_id,
-    );
+            $("#stream_message_recipient_topic .message_header_stream"),
+        );
+    }
     $(document).trigger(new $.Event("compose_started.zulip", opts));
     compose_recipient.update_placeholder_text();
     compose_recipient.update_narrow_to_recipient_visibility();
@@ -148,7 +150,7 @@ export function maybe_scroll_up_selected_message() {
 export function fill_in_opts_from_current_narrowed_view(msg_type, opts) {
     return {
         message_type: msg_type,
-        stream_id: "",
+        stream_id: undefined,
         topic: "",
         private_message_recipient: "",
         trigger: "unknown",
@@ -221,10 +223,12 @@ export function start(msg_type, opts) {
         clear_box();
     }
 
-    const $stream_header_colorblock = $(
+    if (msg_type === "stream") {
-        "#compose_select_recipient_widget_wrapper .stream_header_colorblock",
+        const $stream_header_colorblock = $(
-    );
+            "#compose_select_recipient_widget_wrapper .stream_header_colorblock",
-    stream_bar.decorate(opts.stream_id, $stream_header_colorblock);
+        );
+        stream_bar.decorate(opts.stream_id, $stream_header_colorblock);
+    }
 
     if (msg_type === "private") {
         compose_state.set_compose_recipient_id(compose_state.DIRECT_MESSAGE_ID);

web/src/compose_setup.js

@@ -130,7 +130,7 @@ export function initialize() {
             event.preventDefault();
 
             const stream_id = compose_state.stream_id();
-            if (stream_id === "") {
+            if (stream_id === undefined) {
                 return;
             }
             const sub = stream_data.get_sub_by_id(stream_id);

web/src/compose_state.js

@@ -85,7 +85,7 @@ export function stream_id() {
     if (typeof stream_id === "number") {
         return stream_id;
     }
-    return "";
+    return undefined;
 }
 
 export function stream_name() {
@@ -162,7 +162,7 @@ export function focus_in_empty_compose(consider_start_of_whitespace_message_empt
         case "stream_message_recipient_topic":
             return topic() === "";
         case "compose_select_recipient_widget_wrapper":
-            return stream_id() === "";
+            return stream_id() === undefined;
     }
 
     return false;
@@ -182,7 +182,7 @@ export function has_message_content() {
 
 export function has_full_recipient() {
     if (message_type === "stream") {
-        return stream_id() !== "" && topic() !== "";
+        return stream_id() !== undefined && topic() !== "";
     }
     return private_message_recipient() !== "";
 }

web/src/compose_validate.js

@@ -79,7 +79,7 @@ function get_stream_id_for_textarea($textarea) {
         return Number.parseInt(stream_id_str, 10);
     }
 
-    return compose_state.stream_id() || undefined;
+    return compose_state.stream_id();
 }
 
 export function warn_if_private_stream_is_linked(linked_stream, $textarea) {
@@ -480,7 +480,7 @@ export function validate_stream_message_address_info(stream_name) {
 function validate_stream_message(scheduling_message) {
     const stream_id = compose_state.stream_id();
     const $banner_container = $("#compose_banners");
-    if (stream_id === "") {
+    if (stream_id === undefined) {
         compose_banner.show_error_message(
             $t({defaultMessage: "Please specify a stream."}),
             compose_banner.CLASSNAMES.missing_stream,

web/src/drafts_overlay_ui.js

@@ -26,7 +26,7 @@ function restore_draft(draft_id) {
     const compose_args = {...drafts.restore_message(draft), draft_id};
 
     if (compose_args.type === "stream") {
-        if (draft.stream_id !== "" && draft.topic !== "") {
+        if (draft.stream_id !== undefined && draft.topic !== "") {
             narrow.activate(
                 [
                     {operator: "stream", operand: compose_args.stream_name},

web/src/pill_typeahead.js

@@ -112,7 +112,7 @@ export function set_up($input, pills, opts) {
             return typeahead_helper.sort_recipients({
                 users,
                 query,
-                current_stream_id: "",
+                current_stream_id: undefined,
                 current_topic: undefined,
                 groups,
                 max_num_items: undefined,

web/src/stream_bar.js

@@ -5,9 +5,6 @@ import * as stream_data from "./stream_data";
 // (In particular, if there's a color associated with it,
 //  have that color be reflected here too.)
 export function decorate(stream_id, $element) {
-    if (stream_id === undefined) {
-        return;
-    }
     const color = stream_data.get_color(stream_id);
     $element.css("background-color", color);
 }

web/tests/compose.test.js

@@ -198,7 +198,7 @@ test_ui("send_message", ({override, override_rewire, mock_template}) => {
                 sender_id: new_user.user_id,
                 queue_id: undefined,
                 resend: false,
-                stream_id: "",
+                stream_id: undefined,
                 topic: "",
                 to: `[${alice.user_id}]`,
                 reply_to: "alice@example.com",

web/tests/compose_actions.test.js

@@ -127,7 +127,7 @@ test("start", ({override, override_rewire, mock_template}) => {
 
     // Start stream message
     compose_defaults = {
-        stream_id: "",
+        stream_id: undefined,
         topic: "topic1",
     };
 

web/tests/compose_ui.test.js

@@ -187,7 +187,7 @@ run_test("replace_syntax", ({override}) => {
 run_test("compute_placeholder_text", () => {
     let opts = {
         message_type: "stream",
-        stream_id: "",
+        stream_id: undefined,
         topic: "",
         private_message_recipient: "",
     };
@@ -216,7 +216,7 @@ run_test("compute_placeholder_text", () => {
     // direct message narrows
     opts = {
         message_type: "private",
-        stream_id: "",
+        stream_id: undefined,
         topic: "",
         private_message_recipient: "",
     };

web/tests/stream_data.test.js

@@ -139,7 +139,7 @@ test("basics", () => {
     assert.ok(!stream_data.is_invite_only_by_stream_id(1000));
 
     assert.equal(stream_data.get_color(social.stream_id), "red");
-    assert.equal(stream_data.get_color(""), "#c2c2c2");
+    assert.equal(stream_data.get_color(undefined), "#c2c2c2");
 
     assert.equal(stream_data.get_name("denMARK"), "Denmark");
     assert.equal(stream_data.get_name("unknown Stream"), "unknown Stream");

web/tests/typeahead_helper.test.js

@@ -498,7 +498,7 @@ test("sort_recipients dup bots", () => {
     const recipients = th.sort_recipients({
         users: dup_objects,
         query: "b",
-        current_stream_id: "",
+        current_stream_id: undefined,
         current_topic: "",
     });
     const recipients_email = recipients.map((person) => person.email);