feat(editor): add Markdown formatting shortcuts (#6258)

web/src/components/MemoEditor/Editor/extensions.ts

@@ -3,6 +3,8 @@ import { markdown } from "@codemirror/lang-markdown";
 import { indentUnit } from "@codemirror/language";
 import { Compartment, type Extension } from "@codemirror/state";
 import { placeholder as cmPlaceholder, dropCursor, EditorView, type KeyBinding, keymap } from "@codemirror/view";
+import { runFormattingCommand } from "@/components/MemoEditor/Editor/formatting";
+import type { EditorCommandId } from "@/components/MemoEditor/formatting/commands";
 import { memoMarkdownExtensions } from "@/utils/memo-markdown-extension";
 import { headingDecorations } from "./headingDecorations";
 import { liftListItem, sinkListItem } from "./listIndent";
@@ -11,8 +13,8 @@ import { tagMentionDecorations } from "./tagMentionDecorations";
 import { memoEditorTheme } from "./theme";
 import { uploadAnchorField } from "./uploadAnchors";
 
-// Key bindings layered below the autocomplete keymap so the completion popup's
+// Key bindings layered below the autocomplete keymap so its completion-specific
-// own Tab/Escape win while it is open. On a list item, Tab/Shift-Tab nest /
+// keys win while the popup is open. On a list item, Tab/Shift-Tab nest /
 // outdent it (marker-aware, CommonMark-valid); elsewhere they fall through to
 // indentWithTab's plain indent. Escape blurs the editor so keyboard users keep
 // an escape hatch out of the otherwise Tab-trapping editor.
@@ -28,6 +30,31 @@ const editorKeys: KeyBinding[] = [
   { key: "Shift-Tab", run: liftListItem },
 ];
 
+const formattingKey = (key: string, command: EditorCommandId): KeyBinding => ({
+  key,
+  run: (view) => {
+    runFormattingCommand(view, command);
+    return true;
+  },
+});
+
+// Familiar cross-platform Markdown formatting keys. These stay separate from
+// CodeMirror's Markdown keymap, which only handles structural Enter/Backspace.
+const formattingKeys: KeyBinding[] = [
+  formattingKey("Mod-b", "bold"),
+  formattingKey("Mod-i", "italic"),
+  formattingKey("Shift-Mod-s", "strikethrough"),
+  formattingKey("Mod-e", "code"),
+  formattingKey("Mod-Alt-c", "codeBlock"),
+  formattingKey("Mod-Alt-0", "paragraph"),
+  formattingKey("Shift-Mod-7", "orderedList"),
+  formattingKey("Shift-Mod-8", "bulletList"),
+  formattingKey("Shift-Mod-9", "taskList"),
+  formattingKey("Mod-Alt-1", "heading1"),
+  formattingKey("Mod-Alt-2", "heading2"),
+  formattingKey("Mod-Alt-3", "heading3"),
+];
+
 export interface EditorExtensionsOptions {
   placeholder: string;
   onChange: (markdown: string) => void;
@@ -111,9 +138,11 @@ export function buildEditorExtensions({
     headingDecorations,
     uploadAnchorField,
     // tagAutocomplete must precede the editing keymap so the completion popup's
-    // Enter/Tab/arrow bindings win while it is open.
+    // Enter/Escape/arrow bindings win while it is open.
     tagAutocomplete(getTags),
-    keymap.of([...submitKeys, ...editorKeys, indentWithTab, ...defaultKeymap, ...historyKeymap]),
+    // Formatting keys precede defaultKeymap so the conventional Mod-I italic
+    // shortcut wins over CodeMirror's generic selectParentSyntax binding.
+    keymap.of([...submitKeys, ...editorKeys, ...formattingKeys, indentWithTab, ...defaultKeymap, ...historyKeymap]),
     EditorView.updateListener.of((u) => {
       if (u.docChanged) onChange(u.state.doc.toString());
       // Toolbar active-state depends only on the doc and selection; skip the

web/src/components/MemoEditor/Editor/formatting.ts

@@ -316,28 +316,33 @@ function unwrapLink(view: EditorView): boolean {
   return false;
 }
 
+/** Apply one formatting verb to a CodeMirror view. Shared by the toolbar controller and keymap. */
+export function runFormattingCommand(view: EditorView, command: EditorCommandId, ctx?: EditorCommandContext): void {
+  if (isMarkCommand(command)) return toggleMark(view, command);
+  if (command === "codeBlock") return toggleCodeBlock(view);
+  if (command === "bulletList" || command === "orderedList" || command === "taskList") {
+    return toggleListLine(view, command);
+  }
+  if (command === "heading1") return setHeading(view, 1);
+  if (command === "heading2") return setHeading(view, 2);
+  if (command === "heading3") return setHeading(view, 3);
+  if (command === "paragraph") return setHeading(view, 0);
+  if (command === "link") {
+    // Toggle: inside an existing link, unwrap it to its label.
+    if (unwrapLink(view)) return;
+    const { from, to } = view.state.selection.main;
+    const url = ctx?.url ?? "";
+    // Empty selection: the URL doubles as the label.
+    const label = view.state.sliceDoc(from, to) || url;
+    const insert = `[${label}](${url})`;
+    view.dispatch({ changes: { from, to, insert }, selection: { anchor: from + insert.length } });
+  }
+}
+
 export function createFormattingController(view: EditorView, listeners: Set<() => void>): FormattingController {
   return {
     run(command: EditorCommandId, ctx?: EditorCommandContext) {
-      if (isMarkCommand(command)) return toggleMark(view, command);
+      runFormattingCommand(view, command, ctx);
-      if (command === "codeBlock") return toggleCodeBlock(view);
-      if (command === "bulletList" || command === "orderedList" || command === "taskList") {
-        return toggleListLine(view, command);
-      }
-      if (command === "heading1") return setHeading(view, 1);
-      if (command === "heading2") return setHeading(view, 2);
-      if (command === "heading3") return setHeading(view, 3);
-      if (command === "paragraph") return setHeading(view, 0);
-      if (command === "link") {
-        // Toggle: inside an existing link, unwrap it to its label.
-        if (unwrapLink(view)) return;
-        const { from, to } = view.state.selection.main;
-        const url = ctx?.url ?? "";
-        // Empty selection: the URL doubles as the label.
-        const label = view.state.sliceDoc(from, to) || url;
-        const insert = `[${label}](${url})`;
-        view.dispatch({ changes: { from, to, insert }, selection: { anchor: from + insert.length } });
-      }
     },
     getActiveFormats(): ActiveFormatState {
       const pos = view.state.selection.main.head;

web/src/components/MemoEditor/README.md

@@ -88,6 +88,8 @@ A reducer (`state/reducer.ts`) drives an **external store**, not a `useReducer`
 
 `Editor/extensions.ts` exports `buildEditorExtensions()`, which composes the CodeMirror extension set: `@codemirror/lang-markdown` (with GFM), line wrapping, a reconfigurable placeholder, the editor theme, the `#tag`/`@mention` decoration plugin, the `#tag` autocomplete, and an update listener that pushes document changes back to the reducer via `onChange`. It also binds the save shortcut: `Meta-Enter` and `Ctrl-Enter` both call `onSubmit`, bound explicitly rather than through the platform-dependent `Mod-` so either works everywhere, and ordered ahead of `defaultKeymap`'s own `Mod-Enter` (`insertBlankLine`) so saving never also edits the document. Native CodeMirror paste/drop handlers intercept file payloads before its text insertion behavior and pass them to the attachment layer; ordinary markdown text paste/drop remains CodeMirror-owned.
 
+The app formatting keymap sits ahead of CodeMirror's generic `defaultKeymap`: `Mod-B`/`Mod-I` toggle bold/italic, `Mod-Shift-S` toggles strikethrough, `Mod-E` toggles inline code, `Mod-Alt-C` toggles a code block, `Mod-Alt-0` restores paragraph text, `Mod-Alt-1` through `Mod-Alt-3` select heading levels, and `Mod-Shift-7` through `Mod-Shift-9` toggle ordered, bullet, and task lists. CodeMirror's Markdown keymap remains enabled separately for structural `Enter` and `Backspace` behavior.
+
 `Editor/theme.ts` defines the decorated-source look: a `HighlightStyle` over the Lezer markdown highlight tags (headings, strong, emphasis, code, links, quotes, markers) and an `EditorView.theme`. Colors come from CSS custom properties so light/dark themes just work. This is the editor's own styling — the read-only memo view styles itself separately via `@/lib/markdownStyles`.
 
 ### Tags and mentions

web/tests/editor-keys.test.ts

@@ -27,6 +27,10 @@ function press(view: EditorView, key: string, opts: KeyboardEventInit = {}) {
   view.contentDOM.dispatchEvent(new KeyboardEvent("keydown", { key, bubbles: true, cancelable: true, ...opts }));
 }
 
+function mod(opts: KeyboardEventInit = {}): KeyboardEventInit {
+  return /Mac/.test(navigator.platform) ? { ...opts, metaKey: true } : { ...opts, ctrlKey: true };
+}
+
 /** Place the cursor on the given 1-based line, then press Tab/Shift-Tab. */
 function tabOnLine(view: EditorView, lineNumber: number, shiftKey = false) {
   const line = view.state.doc.line(lineNumber);
@@ -67,6 +71,49 @@ describe("editor key bindings", () => {
     view.destroy();
   });
 
+  it.each([
+    ["bold", "b", {}, "**text**"],
+    ["italic", "i", {}, "*text*"],
+    ["strikethrough", "s", { shiftKey: true }, "~~text~~"],
+    ["inline code", "e", {}, "`text`"],
+    ["code block", "c", { altKey: true }, "```\ntext\n```"],
+    ["ordered list", "7", { shiftKey: true }, "1. text"],
+    ["bullet list", "8", { shiftKey: true }, "- text"],
+    ["task list", "9", { shiftKey: true }, "- [ ] text"],
+    ["heading 1", "1", { altKey: true }, "# text"],
+    ["heading 2", "2", { altKey: true }, "## text"],
+    ["heading 3", "3", { altKey: true }, "### text"],
+  ])("applies %s with its formatting shortcut", (_name, key, modifiers, expected) => {
+    const view = makeView("text");
+    view.dispatch({ selection: { anchor: 0, head: 4 } });
+
+    press(view, key, mod(modifiers));
+
+    expect(view.state.doc.toString()).toBe(expected);
+    view.destroy();
+  });
+
+  it("converts a heading to a paragraph with Mod-Alt-0", () => {
+    const view = makeView("## text");
+    view.dispatch({ selection: { anchor: 4 } });
+
+    press(view, "0", mod({ altKey: true }));
+
+    expect(view.state.doc.toString()).toBe("text");
+    view.destroy();
+  });
+
+  it("uses Mod-I for italic instead of CodeMirror's select-parent-syntax command", () => {
+    const view = makeView("plain");
+    view.dispatch({ selection: { anchor: 0, head: 5 } });
+
+    press(view, "i", mod());
+
+    expect(view.state.doc.toString()).toBe("*plain*");
+    expect(view.state.selection.main).toMatchObject({ from: 1, to: 6 });
+    view.destroy();
+  });
+
   it("Tab indents a non-list line by two spaces", () => {
     const view = makeView("hello");
     view.dispatch({ selection: { anchor: 0 } });