Add .toak-ignore to .gitignore and implement updateGitignore method

Enhanced MarkdownGenerator to update .gitignore programmatically when required, introduced tests for updateGitignore functionality, and ensured `.toak-ignore` is added.

.gitignore

@@ -3,3 +3,4 @@
 /dist/
 prompt.md
 todo
+.toak-ignore

src/MarkdownGenerator.ts

@@ -64,6 +64,7 @@ export class MarkdownGenerator {
   private async initialize(): Promise<void> {
     if (!this.initialized) {
       await this.loadNestedIgnoreFiles();
+      await this.updateGitignore();
       this.initialized = true;
     }
   }
@@ -260,6 +261,58 @@ export class MarkdownGenerator {
     }
   }
 
+  async updateGitignore(): Promise<void> {
+    const gitignorePath = path.join(this.dir, '.gitignore');
+    try {
+      let content = '';
+      try {
+        content = await readFile(gitignorePath, 'utf-8');
+      } catch (error: any) {
+        if (error.code === 'ENOENT') {
+          // .gitignore doesn't exist, create it
+          if (this.verbose) {
+            console.log('File not found, creating a \'.gitignore\' file.');
+          }
+          content = '';
+        } else {
+          throw error;
+        }
+      }
+
+      // Check if entries already exist
+      const lines = content.split('\n');
+      const needsPromptMd = !lines.some(line => line.trim() === 'prompt.md');
+      const needsToakIgnore = !lines.some(line => line.trim() === '.toak-ignore');
+
+      // Add entries if needed
+      if (needsPromptMd || needsToakIgnore) {
+        if (this.verbose) {
+          console.log('Updating .gitignore with prompt.md and .toak-ignore');
+        }
+
+        let newContent = content;
+        if (newContent && !newContent.endsWith('\n')) {
+          newContent += '\n';
+        }
+
+        if (needsPromptMd) {
+          newContent += 'prompt.md\n';
+        }
+
+        if (needsToakIgnore) {
+          newContent += '.toak-ignore\n';
+        }
+
+        await writeFile(gitignorePath, newContent);
+      }
+    } catch (error) {
+      if (this.verbose) {
+        console.error('Error updating .gitignore:', error);
+      }
+      throw error;
+    }
+  }
+
   /**
    * Creates a complete markdown document combining code documentation and todos.
    * @async

test/core.test.ts

@@ -50,8 +50,8 @@ const a = 1;`;
 
     it('should trim whitespace and empty lines', () => {
       const code = `const a = 1;  
-    
-    
+
+
 const b = 2;  `;
       const expected = `const a = 1;
 const b = 2;`;
@@ -381,6 +381,88 @@ const a = 1;
     });
   });
 
+  describe('updateGitignore', () => {
+    it('should update .gitignore with prompt.md and .toak-ignore on first run', async () => {
+      const gitignorePath = path.join('.', '.gitignore');
+
+      // Mock readFile to simulate .gitignore exists but doesn't have the entries
+      const readFileSpy = spyOn(fs, 'readFile').mockResolvedValue('node_modules\ndist\n');
+
+      // Spy on fs.writeFile
+      const writeFileSpy = spyOn(fs, 'writeFile').mockResolvedValue(undefined);
+
+      // Call the method
+      await markdownGenerator.updateGitignore();
+
+      // Verify readFile was called
+      expect(readFileSpy).toHaveBeenCalledWith(gitignorePath, 'utf-8');
+
+      // Verify writeFile was called with correct content
+      expect(writeFileSpy).toHaveBeenCalledWith(
+        gitignorePath, 
+        'node_modules\ndist\nprompt.md\n.toak-ignore\n'
+      );
+
+      // Restore the original implementations
+      readFileSpy.mockRestore();
+      writeFileSpy.mockRestore();
+    });
+
+    it('should not update .gitignore if entries already exist', async () => {
+      const gitignorePath = path.join('.', '.gitignore');
+
+      // Mock readFile to simulate .gitignore already has the entries
+      const readFileSpy = spyOn(fs, 'readFile')
+        .mockResolvedValue('node_modules\ndist\nprompt.md\n.toak-ignore\n');
+
+      // Spy on fs.writeFile
+      const writeFileSpy = spyOn(fs, 'writeFile').mockResolvedValue(undefined);
+
+      // Call the method
+      await markdownGenerator.updateGitignore();
+
+      // Verify readFile was called
+      expect(readFileSpy).toHaveBeenCalledWith(gitignorePath, 'utf-8');
+
+      // Verify writeFile was NOT called
+      expect(writeFileSpy).not.toHaveBeenCalled();
+
+      // Restore the original implementations
+      readFileSpy.mockRestore();
+      writeFileSpy.mockRestore();
+    });
+
+    it('should create .gitignore if it does not exist', async () => {
+      const gitignorePath = path.join('.', '.gitignore');
+
+      // Mock readFile to throw ENOENT error
+      const readFileSpy = spyOn(fs, 'readFile').mockImplementation(() => {
+        const error: any = new Error('File not found');
+        error.code = 'ENOENT';
+        return Promise.reject(error);
+      });
+
+      // Spy on fs.writeFile
+      const writeFileSpy = spyOn(fs, 'writeFile').mockResolvedValue(undefined);
+
+      // Call the method
+      await markdownGenerator.updateGitignore();
+
+      // Verify readFile was called
+      expect(readFileSpy).toHaveBeenCalledWith(gitignorePath, 'utf-8');
+
+      // Verify writeFile was called with correct content
+      expect(writeFileSpy).toHaveBeenCalledWith(
+        gitignorePath, 
+        'prompt.md\n.toak-ignore\n'
+      );
+
+      // Restore the original implementations
+      readFileSpy.mockRestore();
+      writeFileSpy.mockRestore();
+    });
+  });
+
   describe('createMarkdownDocument', () => {
     it('should create markdown document successfully', async () => {
       const mockContent = '# Project Files\n\n## test.txt\n~~~\ntest\n~~~\n\n';