Merge pull request #120 from RooVetGit/prioritize_search_replace_exact_match

More diff fixes and a couple other things

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Roo Cline Changelog
 
+## [2.2.8]
+
+-   More work on diff editing (better matching, indentation, logging)
+
 ## [2.2.7]
 
 -   More fixes to search/replace diffs

README.md

@@ -1,18 +1,19 @@
 # Roo-Cline
 
-A fork of Cline, an autonomous coding agent, optimized for speed and flexibility.
+A fork of Cline, an autonomous coding agent, tweaked for more speed and flexibility. It’s been mainly writing itself recently, with a light touch of human guidance here and there.
-- Auto-approval capabilities for commands, write, and browser operations
+
-- Support for .clinerules per-project custom instructions
+## Features
-- Ability to run side-by-side with Cline
+
-- Unit test coverage (written almost entirely by Roo Cline!)
+- Automatically approve commands, browsing, file writing, and MCP tools
-- Support for playing sound effects
+- Faster, more targeted edits via diffs (even on big files)
-- Support for OpenRouter compression
+- Detects and fixes missing code chunks
-- Support for copying prompts from the history screen
+- `.clinerules` for project-specific instructions
-- Support for editing through diffs / handling truncated full-file edits
+- Drag and drop images into chats
-- Support for newer Gemini models (gemini-exp-1206 and gemini-2.0-flash-exp)
+- Sound effects for feedback
-- Support for dragging and dropping images into chats
+- Quick prompt copying from history
-- Support for auto-approving MCP tools
+- OpenRouter compression support
-- Support for enabling/disabling MCP servers
+- Support for newer Gemini models (gemini-exp-1206, gemini-2.0-flash-exp)
+- Runs alongside the original Cline
 
 ## Disclaimer
 

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "roo-cline",
-  "version": "2.2.7",
+  "version": "2.2.8",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "roo-cline",
-      "version": "2.2.7",
+      "version": "2.2.8",
       "dependencies": {
         "@anthropic-ai/bedrock-sdk": "^0.10.2",
         "@anthropic-ai/sdk": "^0.26.0",

package.json

@@ -3,7 +3,7 @@
   "displayName": "Roo Cline",
   "description": "A fork of Cline, an autonomous coding agent, with some added experimental configuration and automation features.",
   "publisher": "RooVeterinaryInc",
-  "version": "2.2.7",
+  "version": "2.2.8",
   "icon": "assets/icons/rocket.png",
   "galleryBanner": {
     "color": "#617A91",

src/core/Cline.ts

@@ -1237,20 +1237,25 @@ export class Cline {
 								const originalContent = await fs.readFile(absolutePath, "utf-8")
 
 								// Apply the diff to the original content
-								let newContent = this.diffStrategy?.applyDiff(originalContent, diffContent) ?? false
+								const diffResult = this.diffStrategy?.applyDiff(originalContent, diffContent) ?? {
-								if (newContent === false) {
+									success: false,
+									error: "No diff strategy available"
+								}
+								if (!diffResult.success) {
 									this.consecutiveMistakeCount++
-									await this.say("error", `Unable to apply diff to file - contents are out of sync: ${absolutePath}`)
+									const errorDetails = diffResult.details ? `\n\nDetails:\n${JSON.stringify(diffResult.details, null, 2)}` : ''
-									pushToolResult(`Error applying diff to file: ${absolutePath} - contents are out of sync. Try re-reading the relevant lines of the file and applying the diff again.`)
+									await this.say("error", `Unable to apply diff to file: ${absolutePath}\n${diffResult.error}${errorDetails}`)
+									pushToolResult(`Error applying diff to file: ${absolutePath}\n${diffResult.error}${errorDetails}`)
 									break
 								}
+								const newContent = diffResult.content
 
 								this.consecutiveMistakeCount = 0
 
 								// Show diff view before asking for approval
 								this.diffViewProvider.editType = "modify"
 								await this.diffViewProvider.open(relPath);
-								await this.diffViewProvider.update(newContent, true);
+								await this.diffViewProvider.update(diffResult.content, true);
 								await this.diffViewProvider.scrollToFirstDiff();
 
 								const completeMessage = JSON.stringify({

src/core/diff/strategies/__tests__/search-replace.test.ts

@@ -22,7 +22,10 @@ function hello() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe('function hello() {\n    console.log("hello world")\n}\n')
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe('function hello() {\n    console.log("hello world")\n}\n')
+            }
         })
 
         it('should match content with different surrounding whitespace', () => {
@@ -39,7 +42,10 @@ function example() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe('\nfunction example() {\n    return 43;\n}\n\n')
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe('\nfunction example() {\n    return 43;\n}\n\n')
+            }
         })
 
         it('should match content with different indentation in search block', () => {
@@ -56,7 +62,10 @@ function test() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe('    function test() {\n        return false;\n    }\n')
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe('    function test() {\n        return false;\n    }\n')
+            }
         })
 
         it('should handle tab-based indentation', () => {
@@ -73,7 +82,10 @@ function test() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe("function test() {\n\treturn false;\n}\n")
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe("function test() {\n\treturn false;\n}\n")
+            }
         })
 
         it('should preserve mixed tabs and spaces', () => {
@@ -94,7 +106,10 @@ function test() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe("\tclass Example {\n\t    constructor() {\n\t\tthis.value = 1;\n\t    }\n\t}")
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe("\tclass Example {\n\t    constructor() {\n\t\tthis.value = 1;\n\t    }\n\t}")
+            }
         })
 
         it('should handle additional indentation with tabs', () => {
@@ -112,7 +127,10 @@ function test() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe("\tfunction test() {\n\t\t// Add comment\n\t\treturn false;\n\t}")
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe("\tfunction test() {\n\t\t// Add comment\n\t\treturn false;\n\t}")
+            }
         })
 
         it('should preserve exact indentation characters when adding lines', () => {
@@ -131,7 +149,10 @@ function test() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe("\tfunction test() {\n\t\t// First comment\n\t\t// Second comment\n\t\treturn true;\n\t}")
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe("\tfunction test() {\n\t\t// First comment\n\t\t// Second comment\n\t\treturn true;\n\t}")
+            }
         })
 
         it('should handle Windows-style CRLF line endings', () => {
@@ -148,7 +169,10 @@ function test() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe("function test() {\r\n    return false;\r\n}\r\n")
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe("function test() {\r\n    return false;\r\n}\r\n")
+            }
         })
 
         it('should return false if search content does not match', () => {
@@ -165,7 +189,7 @@ function hello() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe(false)
+            expect(result.success).toBe(false)
         })
 
         it('should return false if diff format is invalid', () => {
@@ -173,7 +197,7 @@ function hello() {
             const diffContent = `test.ts\nInvalid diff format`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe(false)
+            expect(result.success).toBe(false)
         })
 
         it('should handle multiple lines with proper indentation', () => {
@@ -192,7 +216,10 @@ function hello() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe('class Example {\n    constructor() {\n        this.value = 0\n    }\n\n    getValue() {\n        // Add logging\n        console.log("Getting value")\n        return this.value\n    }\n}\n')
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe('class Example {\n    constructor() {\n        this.value = 0\n    }\n\n    getValue() {\n        // Add logging\n        console.log("Getting value")\n        return this.value\n    }\n}\n')
+            }
         })
 
         it('should preserve whitespace exactly in the output', () => {
@@ -209,7 +236,10 @@ function hello() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe("    modified\n        still indented\n    end\n")
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe("    modified\n        still indented\n    end\n")
+            }
         })
 
         it('should preserve indentation when adding new lines after existing content', () => {
@@ -226,8 +256,312 @@ function hello() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe('				onScroll={() => updateHighlights()}\n				onDragOver={(e) => {\n					e.preventDefault()\n					e.stopPropagation()\n				}}')
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe('				onScroll={() => updateHighlights()}\n				onDragOver={(e) => {\n					e.preventDefault()\n					e.stopPropagation()\n				}}')
+            }
         })
+
+        it('should handle varying indentation levels correctly', () => {
+            const originalContent = `
+class Example {
+    constructor() {
+        this.value = 0;
+        if (true) {
+            this.init();
+        }
+    }
+}`.trim();
+        
+            const diffContent = `test.ts
+<<<<<<< SEARCH
+    class Example {
+        constructor() {
+            this.value = 0;
+            if (true) {
+                this.init();
+            }
+        }
+    }
+=======
+    class Example {
+        constructor() {
+            this.value = 1;
+            if (true) {
+                this.init();
+                this.setup();
+                this.validate();
+            }
+        }
+    }
+>>>>>>> REPLACE`.trim();
+        
+            const result = strategy.applyDiff(originalContent, diffContent);
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`
+class Example {
+    constructor() {
+        this.value = 1;
+        if (true) {
+            this.init();
+            this.setup();
+            this.validate();
+        }
+    }
+}`.trim());
+            }
+        })
+
+        it('should handle mixed indentation styles in the same file', () => {
+            const originalContent = `class Example {
+    constructor() {
+        this.value = 0;
+        if (true) {
+            this.init();
+        }
+    }
+}`.trim();
+            const diffContent = `test.ts
+<<<<<<< SEARCH
+    constructor() {
+        this.value = 0;
+        if (true) {
+        this.init();
+        }
+    }
+=======
+    constructor() {
+        this.value = 1;
+        if (true) {
+        this.init();
+        this.validate();
+        }
+    }
+>>>>>>> REPLACE`;
+        
+            const result = strategy.applyDiff(originalContent, diffContent);
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`class Example {
+    constructor() {
+        this.value = 1;
+        if (true) {
+        this.init();
+        this.validate();
+        }
+    }
+}`);
+            }
+        })
+        
+        it('should handle Python-style significant whitespace', () => {
+            const originalContent = `def example():
+    if condition:
+        do_something()
+        for item in items:
+            process(item)
+    return True`.trim();
+    const diffContent = `test.ts
+<<<<<<< SEARCH
+    if condition:
+        do_something()
+        for item in items:
+            process(item)
+=======
+    if condition:
+        do_something()
+        while items:
+            item = items.pop()
+            process(item)
+>>>>>>> REPLACE`;
+        
+            const result = strategy.applyDiff(originalContent, diffContent);
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`def example():
+    if condition:
+        do_something()
+        while items:
+            item = items.pop()
+            process(item)
+    return True`);
+            }
+        });
+        
+        it('should preserve empty lines with indentation', () => {
+            const originalContent = `function test() {
+    const x = 1;
+    
+    if (x) {
+        return true;
+    }
+}`.trim();
+            const diffContent = `test.ts
+<<<<<<< SEARCH
+    const x = 1;
+    
+    if (x) {
+=======
+    const x = 1;
+    
+    // Check x
+    if (x) {
+>>>>>>> REPLACE`;
+        
+            const result = strategy.applyDiff(originalContent, diffContent);
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`function test() {
+    const x = 1;
+    
+    // Check x
+    if (x) {
+        return true;
+    }
+}`);
+            }  
+        });
+        
+        it('should handle indentation when replacing entire blocks', () => {
+            const originalContent = `class Test {
+    method() {
+        if (true) {
+            console.log("test");
+        }
+    }
+}`.trim();
+            const diffContent = `test.ts
+<<<<<<< SEARCH
+    method() {
+        if (true) {
+            console.log("test");
+        }
+    }
+=======
+    method() {
+        try {
+            if (true) {
+                console.log("test");
+            }
+        } catch (e) {
+            console.error(e);
+        }
+    }
+>>>>>>> REPLACE`;
+        
+            const result = strategy.applyDiff(originalContent, diffContent);
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`class Test {
+    method() {
+        try {
+            if (true) {
+                console.log("test");
+            }
+        } catch (e) {
+            console.error(e);
+        }
+    }
+}`);
+            }
+        });
+
+        it('should handle negative indentation relative to search content', () => {
+            const originalContent = `class Example {
+    constructor() {
+        if (true) {
+            this.init();
+            this.setup();
+        }
+    }
+}`.trim();
+            const diffContent = `test.ts
+<<<<<<< SEARCH
+            this.init();
+            this.setup();
+=======
+        this.init();
+        this.setup();
+>>>>>>> REPLACE`;
+        
+            const result = strategy.applyDiff(originalContent, diffContent);
+            expect(result.success).toBe(true)
+            if (result.success) {
+            expect(result.content).toBe(`class Example {
+    constructor() {
+        if (true) {
+        this.init();
+        this.setup();
+        }
+    }
+}`);
+            }
+        });
+        
+        it('should handle extreme negative indentation (no indent)', () => {
+    const originalContent = `class Example {
+    constructor() {
+        if (true) {
+            this.init();
+        }
+    }
+}`.trim();
+            const diffContent = `test.ts
+<<<<<<< SEARCH
+            this.init();
+=======
+this.init();
+>>>>>>> REPLACE`;
+        
+            const result = strategy.applyDiff(originalContent, diffContent);
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`class Example {
+    constructor() {
+        if (true) {
+this.init();
+        }
+    }
+}`);
+            }
+        });
+        
+        it('should handle mixed indentation changes in replace block', () => {
+    const originalContent = `class Example {
+    constructor() {
+        if (true) {
+            this.init();
+            this.setup();
+            this.validate();
+        }
+    }
+}`.trim();
+            const diffContent = `test.ts
+<<<<<<< SEARCH
+            this.init();
+            this.setup();
+            this.validate();
+=======
+        this.init();
+            this.setup();
+    this.validate();
+>>>>>>> REPLACE`;
+        
+            const result = strategy.applyDiff(originalContent, diffContent);
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`class Example {
+    constructor() {
+        if (true) {
+        this.init();
+            this.setup();
+    this.validate();
+        }
+    }
+}`);
+            }
+        });
     })
 
     describe('fuzzy matching', () => {
@@ -253,7 +587,10 @@ function getData() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe('function getData() {\n    const data = fetchData();\n    return data.filter(Boolean);\n}\n')
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe('function getData() {\n    const data = fetchData();\n    return data.filter(Boolean);\n}\n')
+            }
         })
 
         it('should not match when content is too different (<90% similar)', () => {
@@ -270,7 +607,7 @@ function processData(data) {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe(false)
+            expect(result.success).toBe(false)
         })
 
         it('should match content with extra whitespace', () => {
@@ -287,7 +624,10 @@ function sum(a, b) {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe('function sum(a, b) {\n    return a + b + 1;\n}')
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe('function sum(a, b) {\n    return a + b + 1;\n}')
+            }
         })
     })
 
@@ -324,7 +664,9 @@ function two() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent, 5, 7)
-            expect(result).toBe(`function one() {
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`function one() {
     return 1;
 }
 
@@ -335,6 +677,7 @@ function two() {
 function three() {
     return 3;
 }`)
+            }
         })
 
         it('should find and replace within buffer zone (5 lines before/after)', () => {
@@ -365,7 +708,9 @@ function three() {
             // Even though we specify lines 5-7, it should still find the match at lines 9-11
             // because it's within the 5-line buffer zone
             const result = strategy.applyDiff(originalContent, diffContent, 5, 7)
-            expect(result).toBe(`function one() {
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`function one() {
     return 1;
 }
 
@@ -376,6 +721,7 @@ function two() {
 function three() {
     return "three";
 }`)
+            }
         })
 
         it('should not find matches outside search range and buffer zone', () => {
@@ -414,7 +760,7 @@ function five() {
             // Searching around function two() (lines 5-7)
             // function five() is more than 5 lines away, so it shouldn't match
             const result = strategy.applyDiff(originalContent, diffContent, 5, 7)
-            expect(result).toBe(false)
+            expect(result.success).toBe(false)
         })
 
         it('should handle search range at start of file', () => {
@@ -439,13 +785,16 @@ function one() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent, 1, 3)
-            expect(result).toBe(`function one() {
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`function one() {
     return "one";
 }
 
 function two() {
     return 2;
 }`)
+            }
         })
 
         it('should handle search range at end of file', () => {
@@ -470,13 +819,16 @@ function two() {
 >>>>>>> REPLACE`
 
             const result = strategy.applyDiff(originalContent, diffContent, 5, 7)
-            expect(result).toBe(`function one() {
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`function one() {
     return 1;
 }
 
 function two() {
     return "two";
 }`)
+            }
         })
 
         it('should match specific instance of duplicate code using line numbers', () => {
@@ -513,7 +865,9 @@ function processData(data) {
 
             // Target the second instance of processData
             const result = strategy.applyDiff(originalContent, diffContent, 10, 12)
-            expect(result).toBe(`function processData(data) {
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`function processData(data) {
     return data.map(x => x * 2);
 }
 
@@ -531,6 +885,7 @@ function processData(data) {
 function moreStuff() {
     console.log("world");
 }`)
+            }
         })
 
         it('should search from start line to end of file when only start_line is provided', () => {
@@ -560,7 +915,9 @@ function three() {
 
             // Only provide start_line, should search from there to end of file
             const result = strategy.applyDiff(originalContent, diffContent, 8)
-            expect(result).toBe(`function one() {
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`function one() {
     return 1;
 }
 
@@ -571,6 +928,7 @@ function two() {
 function three() {
     return "three";
 }`)
+            }
         })
 
         it('should search from start of file to end line when only end_line is provided', () => {
@@ -600,7 +958,9 @@ function one() {
 
             // Only provide end_line, should search from start of file to there
             const result = strategy.applyDiff(originalContent, diffContent, undefined, 4)
-            expect(result).toBe(`function one() {
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`function one() {
     return "one";
 }
 
@@ -611,6 +971,102 @@ function two() {
 function three() {
     return 3;
 }`)
+            }
+        })
+
+        it('should prioritize exact line match over expanded search', () => {
+            const originalContent = `
+function one() {
+    return 1;
+}
+
+function process() {
+    return "old";
+}
+
+function process() {
+    return "old";
+}
+
+function two() {
+    return 2;
+}`
+            const diffContent = `test.ts
+<<<<<<< SEARCH
+function process() {
+    return "old";
+}
+=======
+function process() {
+    return "new";
+}
+>>>>>>> REPLACE`
+
+            // Should match the second instance exactly at lines 10-12
+            // even though the first instance at 6-8 is within the expanded search range
+            const result = strategy.applyDiff(originalContent, diffContent, 10, 12)
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`
+function one() {
+    return 1;
+}
+
+function process() {
+    return "old";
+}
+
+function process() {
+    return "new";
+}
+
+function two() {
+    return 2;
+}`)
+            }
+        })
+
+        it('should fall back to expanded search only if exact match fails', () => {
+            const originalContent = `
+function one() {
+    return 1;
+}
+
+function process() {
+    return "target";
+}
+
+function two() {
+    return 2;
+}`.trim()
+    const diffContent = `test.ts
+<<<<<<< SEARCH
+function process() {
+    return "target";
+}
+=======
+function process() {
+    return "updated";
+}
+>>>>>>> REPLACE`
+
+            // Specify wrong line numbers (3-5), but content exists at 6-8
+            // Should still find and replace it since it's within the expanded range
+            const result = strategy.applyDiff(originalContent, diffContent, 3, 5)
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(`function one() {
+    return 1;
+}
+
+function process() {
+    return "updated";
+}
+
+function two() {
+    return 2;
+}`)
+            }
         })
     })
 

src/core/diff/strategies/__tests__/unified.test.ts

@@ -59,7 +59,10 @@ function calculateTotal(items: number[]): number {
 export { calculateTotal };`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe(expected)
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(expected)
+            }
         })
 
         it('should successfully apply a diff adding a new method', () => {
@@ -93,7 +96,10 @@ export { calculateTotal };`
 }`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe(expected)
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(expected)
+            }
         })
 
         it('should successfully apply a diff modifying imports', () => {
@@ -128,7 +134,10 @@ function App() {
 }`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe(expected)
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(expected)
+            }
         })
 
         it('should successfully apply a diff with multiple hunks', () => {
@@ -190,7 +199,10 @@ async function processFile(path: string) {
 export { processFile };`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe(expected)
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(expected)
+            }
         })
 
         it('should handle empty original content', () => {
@@ -207,7 +219,10 @@ export { processFile };`
 }\n`
 
             const result = strategy.applyDiff(originalContent, diffContent)
-            expect(result).toBe(expected)
+            expect(result.success).toBe(true)
+            if (result.success) {
+                expect(result.content).toBe(expected)
+            }
         })
     })
 })

src/core/diff/strategies/search-replace.ts

@@ -1,4 +1,4 @@
-import { DiffStrategy } from "../types"
+import { DiffStrategy, DiffResult } from "../types"
 
 function levenshteinDistance(a: string, b: string): number {
     const matrix: number[][] = [];
@@ -115,11 +115,20 @@ Your search/replace content here
 </apply_diff>`
     }
 
-    applyDiff(originalContent: string, diffContent: string, startLine?: number, endLine?: number): string | false {
+    applyDiff(originalContent: string, diffContent: string, startLine?: number, endLine?: number): DiffResult {
         // Extract the search and replace blocks
         const match = diffContent.match(/<<<<<<< SEARCH\n([\s\S]*?)\n=======\n([\s\S]*?)\n>>>>>>> REPLACE/);
         if (!match) {
-            return false;
+            // Log detailed format information
+            console.log('Invalid Diff Format Debug:', {
+                expectedFormat: "<<<<<<< SEARCH\\n[search content]\\n=======\\n[replace content]\\n>>>>>>> REPLACE",
+                tip: "Make sure to include both SEARCH and REPLACE sections with correct markers"
+            });
+
+            return {
+                success: false,
+                error: "Invalid diff format - missing required SEARCH/REPLACE sections"
+            };
         }
 
         const [_, searchContent, replaceContent] = match;
@@ -132,7 +141,43 @@ Your search/replace content here
         const replaceLines = replaceContent.split(/\r?\n/);
         const originalLines = originalContent.split(/\r?\n/);
         
-        // Determine search range based on provided line numbers
+        // First try exact line range if provided
+        let matchIndex = -1;
+        let bestMatchScore = 0;
+        let bestMatchContent = "";
+        
+        if (startLine !== undefined && endLine !== undefined) {
+            // Convert to 0-based index
+            const exactStartIndex = startLine - 1;
+            const exactEndIndex = endLine - 1;
+
+            if (exactStartIndex < 0 || exactEndIndex >= originalLines.length) {
+                // Log detailed debug information
+                console.log('Invalid Line Range Debug:', {
+                    requestedRange: { start: startLine, end: endLine },
+                    fileBounds: { start: 1, end: originalLines.length }
+                });
+
+                return {
+                    success: false,
+                    error: `Line range ${startLine}-${endLine} is invalid (file has ${originalLines.length} lines)`,
+                };
+            }
+
+            // Check exact range first
+            const originalChunk = originalLines.slice(exactStartIndex, exactEndIndex + 1).join('\n');
+            const searchChunk = searchLines.join('\n');
+            
+            const similarity = getSimilarity(originalChunk, searchChunk);
+            if (similarity >= this.fuzzyThreshold) {
+                matchIndex = exactStartIndex;
+                bestMatchScore = similarity;
+                bestMatchContent = originalChunk;
+            }
+        }
+
+        // If no match found in exact range, try expanded range
+        if (matchIndex === -1) {
             let searchStartIndex = 0;
             let searchEndIndex = originalLines.length;
 
@@ -146,10 +191,7 @@ Your search/replace content here
                 }
             }
 
-        // Find the search content in the original using fuzzy matching
+            // Find the search content in the expanded range using fuzzy matching
-        let matchIndex = -1;
-        let bestMatchScore = 0;
-        
             for (let i = searchStartIndex; i <= searchEndIndex - searchLines.length; i++) {
                 // Join the lines and calculate overall similarity
                 const originalChunk = originalLines.slice(i, i + searchLines.length).join('\n');
@@ -159,12 +201,26 @@ Your search/replace content here
                 if (similarity > bestMatchScore) {
                     bestMatchScore = similarity;
                     matchIndex = i;
+                    bestMatchContent = originalChunk;
+                }
             }
         }
 
         // Require similarity to meet threshold
         if (matchIndex === -1 || bestMatchScore < this.fuzzyThreshold) {
-            return false;
+            const searchChunk = searchLines.join('\n');
+            // Log detailed debug information to console
+            console.log('Search/Replace Debug Info:', {
+                similarity: bestMatchScore,
+                threshold: this.fuzzyThreshold,
+                searchContent: searchChunk,
+                bestMatch: bestMatchContent || undefined
+            });
+
+            return {
+                success: false,
+                error: `No sufficiently similar match found${startLine !== undefined ? ` near lines ${startLine}-${endLine}` : ''} (${Math.round(bestMatchScore * 100)}% similar, needs ${Math.round(this.fuzzyThreshold * 100)}%)`
+            };
         }
 
         // Get the matched lines from the original content
@@ -192,17 +248,28 @@ Your search/replace content here
             const currentIndent = currentIndentMatch ? currentIndentMatch[0] : '';
             const searchBaseIndent = searchIndents[0] || '';
             
-            // Calculate the relative indentation from the search content
+            // Calculate the relative indentation level
-            const relativeIndent = currentIndent.slice(searchBaseIndent.length);
+            const searchBaseLevel = searchBaseIndent.length;
+            const currentLevel = currentIndent.length;
+            const relativeLevel = currentLevel - searchBaseLevel;
             
-            // Apply the matched indentation plus any relative indentation
+            // If relative level is negative, remove indentation from matched indent
-            return matchedIndent + relativeIndent + line.trim();
+            // If positive, add to matched indent
+            const finalIndent = relativeLevel < 0
+                ? matchedIndent.slice(0, Math.max(0, matchedIndent.length + relativeLevel))
+                : matchedIndent + currentIndent.slice(searchBaseLevel);
+            
+            return finalIndent + line.trim();
         });
 
         // Construct the final content
         const beforeMatch = originalLines.slice(0, matchIndex);
         const afterMatch = originalLines.slice(matchIndex + searchLines.length);
         
-        return [...beforeMatch, ...indentedReplaceLines, ...afterMatch].join(lineEnding);
+        const finalContent = [...beforeMatch, ...indentedReplaceLines, ...afterMatch].join(lineEnding);
+        return {
+            success: true,
+            content: finalContent
+        };
     }
 }

src/core/diff/strategies/unified.ts

@@ -1,5 +1,5 @@
 import { applyPatch } from "diff"
-import { DiffStrategy } from "../types"
+import { DiffStrategy, DiffResult } from "../types"
 
 export class UnifiedDiffStrategy implements DiffStrategy {
     getToolDescription(cwd: string): string {
@@ -108,7 +108,30 @@ Your diff here
 </apply_diff>`
     }
 
-    applyDiff(originalContent: string, diffContent: string): string | false {
+    applyDiff(originalContent: string, diffContent: string): DiffResult {
-        return applyPatch(originalContent, diffContent) as string | false
+        try {
+            const result = applyPatch(originalContent, diffContent)
+            if (result === false) {
+                return {
+                    success: false,
+                    error: "Failed to apply unified diff - patch rejected",
+                    details: {
+                        searchContent: diffContent
+                    }
+                }
+            }
+            return {
+                success: true,
+                content: result
+            }
+        } catch (error) {
+            return {
+                success: false,
+                error: `Error applying unified diff: ${error.message}`,
+                details: {
+                    searchContent: diffContent
+                }
+            }
+        }
     }
 }

src/core/diff/types.ts

@@ -1,6 +1,17 @@
 /**
  * Interface for implementing different diff strategies
  */
+
+export type DiffResult = 
+  | { success: true; content: string }
+  | { success: false; error: string; details?: { 
+      similarity?: number;
+      threshold?: number;
+      matchedRange?: { start: number; end: number };
+      searchContent?: string;
+      bestMatch?: string;
+    }};
+
 export interface DiffStrategy {
     /**
      * Get the tool description for this diff strategy
@@ -15,7 +26,7 @@ export interface DiffStrategy {
      * @param diffContent The diff content in the strategy's format
      * @param startLine Optional line number where the search block starts. If not provided, searches the entire file.
      * @param endLine Optional line number where the search block ends. If not provided, searches the entire file.
-     * @returns The new content after applying the diff, or false if the diff could not be applied
+     * @returns A DiffResult object containing either the successful result or error details
      */
-    applyDiff(originalContent: string, diffContent: string, startLine?: number, endLine?: number): string | false
+    applyDiff(originalContent: string, diffContent: string, startLine?: number, endLine?: number): DiffResult
 }

src/integrations/editor/__tests__/detect-omission.test.ts

@@ -0,0 +1,66 @@
+import { detectCodeOmission } from '../detect-omission'
+
+describe('detectCodeOmission', () => {
+	const originalContent = `function example() {
+  // Some code
+  const x = 1;
+  const y = 2;
+  return x + y;
+}`
+
+	it('should detect square bracket line range omission', () => {
+		const newContent = `[Previous content from line 1-305 remains exactly the same]
+const z = 3;`
+		expect(detectCodeOmission(originalContent, newContent)).toBe(true)
+	})
+
+	it('should detect single-line comment omission', () => {
+		const newContent = `// Lines 1-50 remain unchanged
+const z = 3;`
+		expect(detectCodeOmission(originalContent, newContent)).toBe(true)
+	})
+
+	it('should detect multi-line comment omission', () => {
+		const newContent = `/* Previous content remains the same */
+const z = 3;`
+		expect(detectCodeOmission(originalContent, newContent)).toBe(true)
+	})
+
+	it('should detect HTML-style comment omission', () => {
+		const newContent = `<!-- Existing content unchanged -->
+const z = 3;`
+		expect(detectCodeOmission(originalContent, newContent)).toBe(true)
+	})
+
+	it('should detect JSX-style comment omission', () => {
+		const newContent = `{/* Rest of the code remains the same */}
+const z = 3;`
+		expect(detectCodeOmission(originalContent, newContent)).toBe(true)
+	})
+
+	it('should detect Python-style comment omission', () => {
+		const newContent = `# Previous content remains unchanged
+const z = 3;`
+		expect(detectCodeOmission(originalContent, newContent)).toBe(true)
+	})
+
+	it('should not detect regular comments without omission keywords', () => {
+		const newContent = `// Adding new functionality
+const z = 3;`
+		expect(detectCodeOmission(originalContent, newContent)).toBe(false)
+	})
+
+	it('should not detect when comment is part of original content', () => {
+		const originalWithComment = `// Content remains unchanged
+${originalContent}`
+		const newContent = `// Content remains unchanged
+const z = 3;`
+		expect(detectCodeOmission(originalWithComment, newContent)).toBe(false)
+	})
+
+	it('should not detect code that happens to contain omission keywords', () => {
+		const newContent = `const remains = 'some value';
+const unchanged = true;`
+		expect(detectCodeOmission(originalContent, newContent)).toBe(false)
+	})
+})

src/integrations/editor/detect-omission.ts

@@ -7,7 +7,7 @@
 export function detectCodeOmission(originalFileContent: string, newFileContent: string): boolean {
 	const originalLines = originalFileContent.split("\n")
 	const newLines = newFileContent.split("\n")
-	const omissionKeywords = ["remain", "remains", "unchanged", "rest", "previous", "existing", "..."]
+	const omissionKeywords = ["remain", "remains", "unchanged", "rest", "previous", "existing", "content", "same", "..."]
 
 	const commentPatterns = [
 		/^\s*\/\//, // Single-line comment for most languages
@@ -15,6 +15,7 @@ export function detectCodeOmission(originalFileContent: string, newFileContent:
 		/^\s*\/\*/, // Multi-line comment opening
 		/^\s*{\s*\/\*/, // JSX comment opening
 		/^\s*<!--/, // HTML comment opening
+		/^\s*\[/, // Square bracket notation
 	]
 
 	for (const line of newLines) {