markdown: Don't mutate the message in apply_markdown/render.

Needed for typescript, because we want to preserve
types, so instead of mutating a message object,
we can instead calculate return these values
for a message object before it's created in full.

This commit also renames apply_markdown
to render, see this comment
https://github.com/zulip/zulip/pull/28652#discussion_r1470514780

web/src/compose.js

@@ -358,10 +358,7 @@ export function render_and_show_preview($preview_spinner, $preview_content_box,
             // wrong, users will see a brief flicker of the locally
             // echoed frontend rendering before receiving the
             // authoritative backend rendering from the server).
-            const message_obj = {
+            markdown.render(content);
-                raw_content: content,
-            };
-            markdown.apply_markdown(message_obj);
         }
         channel.post({
             url: "/json/messages/render",

web/src/drafts.js

@@ -345,7 +345,10 @@ export function format_draft(draft) {
     }
 
     try {
-        markdown.apply_markdown(formatted);
+        formatted = {
+            ...formatted,
+            ...markdown.render(formatted.raw_content),
+        };
     } catch (error) {
         // In the unlikely event that there is syntax in the
         // draft content which our Markdown processor is

web/src/echo.js

@@ -174,12 +174,15 @@ export function insert_local_message(message_request, local_id_float, insert_new
     // Shallow clone of message request object that is turned into something suitable
     // for zulip.js:add_message
     // Keep this in sync with changes to compose.create_message_object
-    const message = {...message_request};
+    let message = {...message_request};
 
     message.raw_content = message.content;
 
     // NOTE: This will parse synchronously. We're not using the async pipeline
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
 
     message.content_type = "text/html";
     message.sender_email = people.my_current_email();
@@ -315,7 +318,10 @@ export function edit_locally(message, request) {
             // all flags, so we need to restore those flags that are
             // properties of how the user has interacted with the
             // message, and not its rendering.
-            markdown.apply_markdown(message);
+            message = {
+                ...message,
+                ...markdown.render(message.raw_content),
+            };
             if (request.starred !== undefined) {
                 message.starred = request.starred;
             }
@@ -336,6 +342,7 @@ export function edit_locally(message, request) {
     }
     stream_list.update_streams_sidebar();
     pm_list.update_private_messages();
+    return message;
 }
 
 export function reify_message_id(local_id, server_id) {

web/src/info_overlay.js

@@ -246,8 +246,10 @@ Coffee`,
 export function set_up_toggler() {
     for (const row of markdown_help_rows) {
         if (row.markdown && !row.output_html) {
-            const message = {raw_content: row.markdown};
+            const message = {
-            markdown.apply_markdown(message);
+                raw_content: row.markdown,
+                ...markdown.render(row.markdown),
+            };
             row.output_html = util.clean_user_content_links(message.content);
         }
     }

web/src/markdown.js

@@ -675,14 +675,15 @@ export function initialize(helper_config) {
     web_app_helpers = helper_config;
 }
 
-export function apply_markdown(message) {
+export function render(raw_content) {
     // This is generally only intended to be called by the web app. Most
     // other platforms should call parse().
-    const raw_content = message.raw_content;
     const {content, flags} = parse({raw_content, helper_config: web_app_helpers});
-    message.content = content;
+    return {
-    message.flags = flags;
+        content,
-    message.is_me_message = is_status_message(raw_content);
+        flags,
+        is_me_message: is_status_message(raw_content),
+    };
 }
 
 export function add_topic_links(message) {

web/src/message_edit.js

@@ -854,7 +854,7 @@ export function end_message_edit(message_id) {
 export function save_inline_topic_edit($row) {
     const msg_list = message_lists.current;
     let message_id = rows.id_for_recipient_row($row);
-    const message = message_lists.current.get(message_id);
+    let message = message_lists.current.get(message_id);
 
     const old_topic = message.topic;
     const new_topic = $row.find(".inline_topic_edit").val();
@@ -871,7 +871,7 @@ export function save_inline_topic_edit($row) {
 
     if (message.locally_echoed) {
         if (topic_changed) {
-            echo.edit_locally(message, {new_topic});
+            message = echo.edit_locally(message, {new_topic});
             $row = message_lists.current.get_row(message_id);
         }
         end_inline_topic_edit($row);
@@ -946,7 +946,7 @@ export function save_message_row_edit($row) {
     );
     const msg_list = message_lists.current;
     let message_id = rows.id($row);
-    const message = message_lists.current.get(message_id);
+    let message = message_lists.current.get(message_id);
     let changed = false;
     let edit_locally_echoed = false;
 
@@ -981,7 +981,7 @@ export function save_message_row_edit($row) {
     if (message.locally_echoed) {
         if (new_content !== message.raw_content) {
             // `edit_locally` handles the case where `new_topic/new_stream_id` is undefined
-            echo.edit_locally(message, {
+            message = echo.edit_locally(message, {
                 raw_content: new_content,
             });
             $row = message_lists.current.get_row(message_id);
@@ -1027,7 +1027,7 @@ export function save_message_row_edit($row) {
         // the message is acknowledged by the server.
         message.local_edit_timestamp = Math.round(Date.now() / 1000);
 
-        echo.edit_locally(message, currently_echoing_messages.get(message_id));
+        message = echo.edit_locally(message, currently_echoing_messages.get(message_id));
 
         $row = message_lists.current.get_row(message_id);
         end_message_row_edit($row);
@@ -1054,14 +1054,14 @@ export function save_message_row_edit($row) {
                 message_id = rows.id($row);
 
                 if (edit_locally_echoed) {
-                    const echoed_message = message_store.get(message_id);
+                    let echoed_message = message_store.get(message_id);
                     const echo_data = currently_echoing_messages.get(message_id);
 
                     delete echoed_message.local_edit_timestamp;
                     currently_echoing_messages.delete(message_id);
 
                     // Restore the original content.
-                    echo.edit_locally(echoed_message, {
+                    echoed_message = echo.edit_locally(echoed_message, {
                         content: echo_data.orig_content,
                         raw_content: echo_data.orig_raw_content,
                         mentioned: echo_data.mentioned,

web/tests/compose.test.js

@@ -235,7 +235,7 @@ test_ui("send_message", ({override, override_rewire, mock_template}) => {
         override(compose_pm_pill, "get_emails", () => "alice@example.com");
 
         const server_message_id = 127;
-        override(markdown, "apply_markdown", noop);
+        override(markdown, "render", noop);
         override(markdown, "add_topic_links", noop);
 
         override_rewire(echo, "try_deliver_locally", (message_request) => {
@@ -730,7 +730,7 @@ test_ui("on_events", ({override, override_rewire}) => {
         assert.ok(make_indicator_called);
         assert_visibilities();
 
-        let apply_markdown_called = false;
+        let render_called = false;
         $("textarea#compose-textarea").val("foobarfoobar");
         setup_visibilities();
         setup_mock_markdown_contains_backend_only_syntax("foobarfoobar", false);
@@ -738,15 +738,14 @@ test_ui("on_events", ({override, override_rewire}) => {
 
         current_message = "foobarfoobar";
 
-        override(markdown, "apply_markdown", (msg) => {
+        override(markdown, "render", (raw_content) => {
-            assert.equal(msg.raw_content, "foobarfoobar");
+            assert.equal(raw_content, "foobarfoobar");
-            apply_markdown_called = true;
+            render_called = true;
-            return msg;
         });
 
         handler(event);
 
-        assert.ok(apply_markdown_called);
+        assert.ok(render_called);
         assert_visibilities();
         assert.equal($("#compose .preview_content").html(), "Server: foobarfoobar");
     })();

web/tests/drafts.test.js

@@ -31,7 +31,7 @@ set_global("setTimeout", (f, delay) => {
     f();
 });
 mock_esm("../src/markdown", {
-    apply_markdown: noop,
+    render: noop,
 });
 mock_esm("../src/overlays", {
     open_overlay: noop,

web/tests/echo.test.js

@@ -221,12 +221,12 @@ run_test("insert_local_message streams", ({override}) => {
 
     const local_id_float = 101.01;
 
-    let apply_markdown_called = false;
+    let render_called = false;
     let add_topic_links_called = false;
     let insert_message_called = false;
 
-    override(markdown, "apply_markdown", () => {
+    override(markdown, "render", () => {
-        apply_markdown_called = true;
+        render_called = true;
     });
 
     override(markdown, "add_topic_links", () => {
@@ -251,7 +251,7 @@ run_test("insert_local_message streams", ({override}) => {
     };
     echo.insert_local_message(message_request, local_id_float, insert_new_messages);
 
-    assert.ok(apply_markdown_called);
+    assert.ok(render_called);
     assert.ok(add_topic_links_called);
     assert.ok(insert_message_called);
 });
@@ -274,7 +274,7 @@ run_test("insert_local_message direct message", ({override}) => {
     people.initialize(page_params.user_id, params);
 
     let add_topic_links_called = false;
-    let apply_markdown_called = false;
+    let render_called = false;
     let insert_message_called = false;
 
     const insert_new_messages = ([message]) => {
@@ -282,8 +282,8 @@ run_test("insert_local_message direct message", ({override}) => {
         insert_message_called = true;
     };
 
-    override(markdown, "apply_markdown", () => {
+    override(markdown, "render", () => {
-        apply_markdown_called = true;
+        render_called = true;
     });
 
     override(markdown, "add_topic_links", () => {
@@ -299,14 +299,14 @@ run_test("insert_local_message direct message", ({override}) => {
     };
     echo.insert_local_message(message_request, local_id_float, insert_new_messages);
     assert.ok(add_topic_links_called);
-    assert.ok(apply_markdown_called);
+    assert.ok(render_called);
     assert.ok(insert_message_called);
 });
 
 run_test("test reify_message_id", ({override}) => {
     const local_id_float = 103.01;
 
-    override(markdown, "apply_markdown", noop);
+    override(markdown, "render", noop);
     override(markdown, "add_topic_links", noop);
 
     const message_request = {

web/tests/markdown.test.js

@@ -263,9 +263,12 @@ test("marked_shared", () => {
             continue;
         }
 
-        const message = {raw_content: test.input};
+        let message = {raw_content: test.input};
         user_settings.translate_emoticons = test.translate_emoticons || false;
-        markdown.apply_markdown(message);
+        message = {
+            ...message,
+            ...markdown.render(message.raw_content),
+        };
         const output = message.content;
         const error_message = `Failure in test: ${test.name}`;
         if (test.marked_expected_output) {
@@ -281,20 +284,32 @@ test("marked_shared", () => {
 
 test("message_flags", () => {
     let message = {raw_content: "@**Leo**"};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.ok(!message.flags.includes("mentioned"));
 
     message = {raw_content: "@**Cordelia, Lear's daughter**"};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.ok(message.flags.includes("mentioned"));
 
     message = {raw_content: "@**all**"};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.ok(message.flags.includes("stream_wildcard_mentioned"));
     assert.ok(!message.flags.includes("topic_wildcard_mentioned"));
 
     message = {raw_content: "@**topic**"};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.ok(!message.flags.includes("stream_wildcard_mentioned"));
     assert.ok(message.flags.includes("topic_wildcard_mentioned"));
 });
@@ -617,8 +632,7 @@ test("marked", () => {
         const input = test_case.input;
         const expected = test_case.expected;
 
-        const message = {raw_content: input};
+        const message = markdown.render(input);
-        markdown.apply_markdown(message);
         const output = message.content;
         assert.equal(output, expected);
     }
@@ -717,20 +731,29 @@ test("topic_links", () => {
 test("message_flags", () => {
     let input = "/me is testing this";
     let message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
 
     assert.equal(message.is_me_message, true);
     assert.ok(!message.unread);
 
     input = "/me is testing\nthis";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
 
     assert.equal(message.is_me_message, true);
 
     input = "testing this @**all** @**Cordelia, Lear's daughter**";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.is_me_message, false);
     assert.equal(message.flags.includes("mentioned"), true);
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), true);
@@ -738,7 +761,10 @@ test("message_flags", () => {
 
     input = "test @**everyone**";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.is_me_message, false);
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), true);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
@@ -746,7 +772,10 @@ test("message_flags", () => {
 
     input = "test @**stream**";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.is_me_message, false);
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), true);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
@@ -754,7 +783,10 @@ test("message_flags", () => {
 
     input = "test @**topic**";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.is_me_message, false);
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), true);
@@ -762,98 +794,140 @@ test("message_flags", () => {
 
     input = "test @all";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "test @everyone";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "test @topic";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "test @any";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "test @alleycat.com";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "test @*hamletcharacters*";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), true);
 
     input = "test @*backend*";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "test @**invalid_user**";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "test @_**all**";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "> test @**all**";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "test @_**topic**";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "> test @**topic**";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "test @_*hamletcharacters*";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
 
     input = "> test @*hamletcharacters*";
     message = {topic: "No links here", raw_content: input};
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.flags.includes("stream_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("topic_wildcard_mentioned"), false);
     assert.equal(message.flags.includes("mentioned"), false);
@@ -929,9 +1003,12 @@ test("parse_non_message", () => {
 });
 
 test("missing unicode emojis", ({override}) => {
-    const message = {raw_content: "\u{1F6B2}"};
+    let message = {raw_content: "\u{1F6B2}"};
 
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(
         message.content,
         '<p><span aria-label="bike" class="emoji emoji-1f6b2" role="img" title="bike">:bike:</span></p>',
@@ -941,7 +1018,10 @@ test("missing unicode emojis", ({override}) => {
     override(emoji_codes.codepoint_to_name, "1f6b2", undefined);
 
     markdown.initialize(markdown_config.get_helpers());
-    markdown.apply_markdown(message);
+    message = {
+        ...message,
+        ...markdown.render(message.raw_content),
+    };
     assert.equal(message.content, "<p>\u{1F6B2}</p>");
 });
 
@@ -952,7 +1032,7 @@ test("katex_throws_unexpected_exceptions", ({override_rewire}) => {
             throw new Error("some-exception");
         },
     });
-    assert.throws(() => markdown.apply_markdown(message), {
+    assert.throws(() => markdown.render(message.raw_content), {
         name: "Error",
         message: "some-exception\nPlease report this to https://zulip.com/development-community/",
     });