refactor(cli): simplify handleImageCommand and add tests

- Simplify handleImageCommand to return just a string instead of complex object
- Use split() instead of regex for parsing
- Remove unused postUserMessage callback pattern
- Add unit tests for argument parsing behavior

Author: brandonkachen

cli/src/commands/__tests__/image.test.ts

@@ -0,0 +1,95 @@
+import { describe, test, expect } from 'bun:test'
+
+/**
+ * Tests for the handleImageCommand argument parsing behavior.
+ * 
+ * These tests verify the parsing logic independently of the actual
+ * validateAndAddImage implementation by testing the parsing function directly.
+ */
+
+// Extract the parsing logic that handleImageCommand uses
+// New simplified implementation: split on whitespace
+function parseImageCommandArgs(args: string): {
+  imagePath: string | null
+  message: string
+} {
+  const [imagePath, ...rest] = args.trim().split(/\s+/)
+  
+  if (!imagePath) {
+    return { imagePath: null, message: '' }
+  }
+  
+  return { imagePath, message: rest.join(' ') }
+}
+
+describe('handleImageCommand parsing', () => {
+  describe('argument parsing', () => {
+    test('parses image path only', () => {
+      const result = parseImageCommandArgs('./screenshot.png')
+      expect(result.imagePath).toBe('./screenshot.png')
+      expect(result.message).toBe('')
+    })
+
+    test('parses image path with message', () => {
+      const result = parseImageCommandArgs('./screenshot.png please analyze this')
+      expect(result.imagePath).toBe('./screenshot.png')
+      expect(result.message).toBe('please analyze this')
+    })
+
+    test('parses image path with multi-word message', () => {
+      const result = parseImageCommandArgs('./image.jpg what is in this picture?')
+      expect(result.imagePath).toBe('./image.jpg')
+      expect(result.message).toBe('what is in this picture?')
+    })
+
+    test('handles absolute paths with message', () => {
+      const result = parseImageCommandArgs('/path/to/file.png describe the UI')
+      expect(result.imagePath).toBe('/path/to/file.png')
+      expect(result.message).toBe('describe the UI')
+    })
+
+    test('trims whitespace from input', () => {
+      const result = parseImageCommandArgs('  ./image.png  ')
+      expect(result.imagePath).toBe('./image.png')
+      expect(result.message).toBe('')
+    })
+
+    test('handles multiple spaces between path and message', () => {
+      const result = parseImageCommandArgs('./image.png    hello world')
+      expect(result.imagePath).toBe('./image.png')
+      // The regex only captures content after the first whitespace group
+      expect(result.message).toBe('hello world')
+    })
+  })
+
+  describe('invalid input handling', () => {
+    test('returns null imagePath for empty input', () => {
+      const result = parseImageCommandArgs('')
+      expect(result.imagePath).toBeNull()
+      expect(result.message).toBe('')
+    })
+
+    test('returns null imagePath for whitespace-only input', () => {
+      const result = parseImageCommandArgs('   ')
+      expect(result.imagePath).toBeNull()
+      expect(result.message).toBe('')
+    })
+  })
+
+  describe('edge cases', () => {
+    test('handles filenames with extensions', () => {
+      const result = parseImageCommandArgs('image.jpeg')
+      expect(result.imagePath).toBe('image.jpeg')
+    })
+
+    test('handles relative paths', () => {
+      const result = parseImageCommandArgs('../screenshots/test.png')
+      expect(result.imagePath).toBe('../screenshots/test.png')
+    })
+
+    test('handles tilde paths', () => {
+      const result = parseImageCommandArgs('~/Downloads/image.png')
+      expect(result.imagePath).toBe('~/Downloads/image.png')
+    })
+  })
+})

cli/src/commands/command-registry.ts

@@ -223,8 +223,7 @@ export const COMMAND_REGISTRY: CommandDefinition[] = [
 
       // If user provided a path directly, process it immediately
       if (trimmedArgs) {
-        const result = await handleImageCommand(trimmedArgs)
-        params.setMessages((prev) => result.postUserMessage(prev))
+        await handleImageCommand(trimmedArgs)
         params.saveToHistory(params.inputValue.trim())
         clearInput(params)
         return

cli/src/commands/image.ts

@@ -1,45 +1,20 @@
 import { getProjectRoot } from '../project-files'
 import { validateAndAddImage } from '../utils/add-pending-image'
-import { getSystemMessage } from '../utils/message-history'
-
-import type { PostUserMessageFn } from '../types/contracts/send-message'
 
 /**
  * Handle the /image command to attach an image file.
  * Usage: /image <path> [message]
  * Example: /image ./screenshot.png please analyze this
+ * 
+ * Returns the optional message as transformedPrompt (empty string if none).
+ * Errors are shown in the pending images banner with auto-remove.
  */
-export async function handleImageCommand(args: string): Promise<{
-  postUserMessage: PostUserMessageFn
-  transformedPrompt?: string
-}> {
-  const trimmedArgs = args.trim()
-
-  // Parse the path and optional message
-  // The path is the first argument (up to first space or the whole string)
-  const parts = trimmedArgs.match(/^(\S+)(?:\s+(.*))?$/)
-  if (!parts) {
-    const postUserMessage: PostUserMessageFn = (prev) => [
-      ...prev,
-      getSystemMessage('❌ Invalid image command format. Use: /image <path> [message]'),
-    ]
-    return { postUserMessage }
-  }
-
-  const [, imagePath, message] = parts
-  const projectRoot = getProjectRoot()
-
-  // Validate and add the image (handles path resolution, format check, and processing)
-  // Errors are shown in the pending images banner with auto-remove
-  await validateAndAddImage(imagePath, projectRoot)
-
-  // Use the optional message as the prompt, or empty to just attach the image
-  const transformedPrompt = message || ''
-
-  const postUserMessage: PostUserMessageFn = (prev) => prev
-
-  return {
-    postUserMessage,
-    transformedPrompt,
+export async function handleImageCommand(args: string): Promise<string> {
+  const [imagePath, ...rest] = args.trim().split(/\s+/)
+  
+  if (imagePath) {
+    await validateAndAddImage(imagePath, getProjectRoot())
   }
+  
+  return rest.join(' ')
 }