refactor: add markdown renderer tests and remove dead IPC code

- Add 18 unit tests for marked-options-factory covering:
  - Image renderer (sizing syntax, lazy loading, dimensions)
  - Paragraph renderer (headings h1./h2. syntax)
  - parseImageDimensionsFromTitle helper
  - preprocessMarkdown hook
- Export parseImageDimensionsFromTitle and preprocessMarkdown for testability
- Remove unused IPC.TOGGLE_FULLSCREEN event and handler
  (F11 fullscreen is handled directly in main-window.ts)

electron/ipc-handlers/app-control.ts

@@ -78,11 +78,4 @@ export const initAppControlIpc = (): void => {
       });
     }
   });
-
-  ipcMain.on(IPC.TOGGLE_FULLSCREEN, () => {
-    const mainWin = getWin();
-    if (mainWin) {
-      mainWin.setFullScreen(!mainWin.isFullScreen());
-    }
-  });
 };

electron/shared-with-frontend/ipc-events.const.ts

@@ -72,8 +72,6 @@ export enum IPC {
   UPDATE_SETTINGS = 'UPDATE_SETTINGS',
   UPDATE_TITLE_BAR_DARK_MODE = 'UPDATE_TITLE_BAR_DARK_MODE',
 
-  TOGGLE_FULLSCREEN = 'TOGGLE_FULLSCREEN',
-
   // maybe_UPDATE_CURRENT_TASK = 'UPDATE_CURRENT_TASK',
   // maybe_IS_IDLE = 'IS_IDLE',
   // maybe_IS_BUSY = 'IS_BUSY',

src/app/ui/marked-options-factory.spec.ts

@@ -1,4 +1,8 @@
-import { markedOptionsFactory } from './marked-options-factory';
+import {
+  markedOptionsFactory,
+  parseImageDimensionsFromTitle,
+  preprocessMarkdown,
+} from './marked-options-factory';
 
 describe('markedOptionsFactory', () => {
   let options: ReturnType<typeof markedOptionsFactory>;
@@ -125,7 +129,196 @@ describe('markedOptionsFactory', () => {
     });
   });
 
+  describe('image renderer', () => {
+    it('should render basic image with alt text', () => {
+      const result = options.renderer!.image({
+        href: 'http://example.com/image.png',
+        title: null,
+        text: 'Alt text',
+      } as any);
+      expect(result).toContain('src="http://example.com/image.png"');
+      expect(result).toContain('alt="Alt text"');
+      expect(result).toContain('loading="lazy"');
+    });
+
+    it('should render image with width and height from title', () => {
+      const result = options.renderer!.image({
+        href: 'http://example.com/image.png',
+        title: '200|150',
+        text: 'Sized image',
+      } as any);
+      expect(result).toContain('width="200"');
+      expect(result).toContain('height="150"');
+      expect(result).not.toContain('title=');
+    });
+
+    it('should render image with width only', () => {
+      const result = options.renderer!.image({
+        href: 'http://example.com/image.png',
+        title: '300|',
+        text: 'Width only',
+      } as any);
+      expect(result).toContain('width="300"');
+      expect(result).not.toContain('height=');
+    });
+
+    it('should render image with height only', () => {
+      const result = options.renderer!.image({
+        href: 'http://example.com/image.png',
+        title: '|250',
+        text: 'Height only',
+      } as any);
+      expect(result).toContain('height="250"');
+      expect(result).not.toContain('width=');
+    });
+
+    it('should render regular title when not in dimension format', () => {
+      const result = options.renderer!.image({
+        href: 'http://example.com/image.png',
+        title: 'A descriptive title',
+        text: 'Image',
+      } as any);
+      expect(result).toContain('title="A descriptive title"');
+      expect(result).not.toContain('width=');
+      expect(result).not.toContain('height=');
+    });
+
+    it('should handle null title', () => {
+      const result = options.renderer!.image({
+        href: 'http://example.com/image.png',
+        title: null,
+        text: 'No title',
+      } as any);
+      expect(result).not.toContain('title=');
+      expect(result).toContain('alt="No title"');
+    });
+  });
+
+  describe('paragraph renderer', () => {
+    it('should render simple paragraph', () => {
+      const mockParser = {
+        parseInline: (tokens: any[]) =>
+          tokens.map((t: any) => t.raw || t.text || '').join(''),
+      };
+      const paragraphRenderer = options.renderer!.paragraph.bind({ parser: mockParser });
+
+      const result = paragraphRenderer({
+        tokens: [{ type: 'text', raw: 'Simple paragraph', text: 'Simple paragraph' }],
+      } as any);
+      expect(result).toBe('<p>Simple paragraph</p>');
+    });
+
+    it('should convert h1. syntax to heading', () => {
+      const mockParser = {
+        parseInline: (tokens: any[]) =>
+          tokens.map((t: any) => t.raw || t.text || '').join(''),
+      };
+      const paragraphRenderer = options.renderer!.paragraph.bind({ parser: mockParser });
+
+      const result = paragraphRenderer({
+        tokens: [{ type: 'text', raw: 'h1. My Heading', text: 'h1. My Heading' }],
+      } as any);
+      expect(result).toBe('<h1> My Heading</h1>');
+    });
+
+    it('should convert h2. syntax to heading', () => {
+      const mockParser = {
+        parseInline: (tokens: any[]) =>
+          tokens.map((t: any) => t.raw || t.text || '').join(''),
+      };
+      const paragraphRenderer = options.renderer!.paragraph.bind({ parser: mockParser });
+
+      const result = paragraphRenderer({
+        tokens: [{ type: 'text', raw: 'h2. Subheading', text: 'h2. Subheading' }],
+      } as any);
+      expect(result).toBe('<h2> Subheading</h2>');
+    });
+  });
+
   // Note: URL auto-linking is handled automatically by marked v17 with gfm: true.
   // We intentionally do NOT override renderer.text for this - the lexer converts
   // URLs to link tokens before they reach the text renderer.
 });
+
+describe('parseImageDimensionsFromTitle', () => {
+  it('should parse width and height from title', () => {
+    const result = parseImageDimensionsFromTitle('200|150');
+    expect(result).toEqual({ width: '200', height: '150' });
+  });
+
+  it('should parse width only', () => {
+    const result = parseImageDimensionsFromTitle('300|');
+    expect(result).toEqual({ width: '300', height: undefined });
+  });
+
+  it('should parse height only', () => {
+    const result = parseImageDimensionsFromTitle('|250');
+    expect(result).toEqual({ width: undefined, height: '250' });
+  });
+
+  it('should return empty object for null title', () => {
+    const result = parseImageDimensionsFromTitle(null);
+    expect(result).toEqual({});
+  });
+
+  it('should return empty object for non-dimension format', () => {
+    const result = parseImageDimensionsFromTitle('A regular title');
+    expect(result).toEqual({});
+  });
+
+  it('should return empty object for empty string', () => {
+    const result = parseImageDimensionsFromTitle('');
+    expect(result).toEqual({});
+  });
+
+  it('should handle pipe only', () => {
+    const result = parseImageDimensionsFromTitle('|');
+    expect(result).toEqual({ width: undefined, height: undefined });
+  });
+});
+
+describe('preprocessMarkdown', () => {
+  it('should convert image sizing syntax to title format', () => {
+    const input = '![alt text](http://example.com/image.png =200x150)';
+    const result = preprocessMarkdown(input);
+    expect(result).toBe('![alt text](http://example.com/image.png "200|150")');
+  });
+
+  it('should handle width only', () => {
+    const input = '![alt](url.png =300x)';
+    const result = preprocessMarkdown(input);
+    expect(result).toBe('![alt](url.png "300|")');
+  });
+
+  it('should handle height only', () => {
+    const input = '![alt](url.png =x250)';
+    const result = preprocessMarkdown(input);
+    expect(result).toBe('![alt](url.png "|250")');
+  });
+
+  it('should handle multiple images in text', () => {
+    const input = 'Some text ![img1](a.png =100x100) more ![img2](b.png =200x200) end';
+    const result = preprocessMarkdown(input);
+    expect(result).toBe(
+      'Some text ![img1](a.png "100|100") more ![img2](b.png "200|200") end',
+    );
+  });
+
+  it('should not modify images without sizing syntax', () => {
+    const input = '![alt](http://example.com/image.png)';
+    const result = preprocessMarkdown(input);
+    expect(result).toBe('![alt](http://example.com/image.png)');
+  });
+
+  it('should not modify images with regular title', () => {
+    const input = '![alt](http://example.com/image.png "A title")';
+    const result = preprocessMarkdown(input);
+    expect(result).toBe('![alt](http://example.com/image.png "A title")');
+  });
+
+  it('should preserve other markdown content', () => {
+    const input = '# Header\n\n![img](url.png =50x50)\n\nParagraph';
+    const result = preprocessMarkdown(input);
+    expect(result).toBe('# Header\n\n![img](url.png "50|50")\n\nParagraph');
+  });
+});

src/app/ui/marked-options-factory.ts

@@ -6,7 +6,7 @@ import { Hooks } from 'marked';
  * The title format is expected to be "width|height" (e.g., "200|150", "200|", "|150")
  * This is generated by preprocessing.
  */
-const parseImageDimensionsFromTitle = (
+export const parseImageDimensionsFromTitle = (
   title: string | null,
 ): { width?: string; height?: string } => {
   if (!title) {
@@ -30,7 +30,7 @@ const parseImageDimensionsFromTitle = (
  * Converts: ![alt](url =WIDTHxHEIGHT) -> ![alt](url "WIDTH|HEIGHT")
  * This allows marked.js to parse it as a valid image with a title.
  */
-const preprocessMarkdown = (markdown: string): string => {
+export const preprocessMarkdown = (markdown: string): string => {
   // Match: ![alt](url =WIDTHxHEIGHT) or ![alt](url =WIDTHx) or ![alt](url =xHEIGHT)
   // Capture groups: 1=alt, 2=url, 3=width, 4=height
   return markdown.replace(