fix: preserve trailing newlines in stripLineNumbers for apply_diff (#8020)

src/core/diff/strategies/__tests__/multi-search-replace-issue-8020.spec.ts

@@ -0,0 +1,61 @@
+import { MultiSearchReplaceDiffStrategy } from "../multi-search-replace"
+
+describe("MultiSearchReplaceDiffStrategy - Issue #8020", () => {
+	let strategy: MultiSearchReplaceDiffStrategy
+
+	beforeEach(() => {
+		strategy = new MultiSearchReplaceDiffStrategy()
+	})
+
+	it("should strip line numbers from last line without trailing newline", async () => {
+		// This reproduces the exact issue from #8020
+		// The problem was that the regex was removing the trailing newline,
+		// which caused stripLineNumbers to fail on the last line
+		const originalContent = "line 1\nline 2\nline 3"
+
+		// Diff content with line numbers on every line including the last
+		const diffContent = `<<<<<<< SEARCH
+1 | line 1
+2 | line 2
+3 | line 3
+=======
+1 | line 1
+2 | modified
+3 | line 3
+>>>>>>> REPLACE`
+
+		const result = await strategy.applyDiff(originalContent, diffContent)
+
+		if (!result.success) {
+			console.error("Failed with:", result.error || result.failParts)
+		}
+
+		expect(result.success).toBe(true)
+		if (result.success) {
+			expect(result.content).toBe("line 1\nmodified\nline 3")
+		}
+	})
+
+	it("should handle the exact case from issue #8020", async () => {
+		// Simplified version of the actual case
+		const originalContent = "some code);"
+
+		const diffContent = `<<<<<<< SEARCH
+1479 | some code);
+=======
+1488 | some code);
+>>>>>>> REPLACE`
+
+		const result = await strategy.applyDiff(originalContent, diffContent)
+
+		if (!result.success) {
+			console.error("Failed with:", result.error || result.failParts)
+		}
+
+		expect(result.success).toBe(true)
+		if (result.success) {
+			// Content should remain the same since we're just replacing with the same
+			expect(result.content).toBe("some code);")
+		}
+	})
+})

src/core/diff/strategies/__tests__/multi-search-replace-line-number.spec.ts

@@ -0,0 +1,112 @@
+import { MultiSearchReplaceDiffStrategy } from "../multi-search-replace"
+
+describe("MultiSearchReplaceDiffStrategy - Line Number Stripping", () => {
+	describe("line number stripping at last line", () => {
+		let strategy: MultiSearchReplaceDiffStrategy
+
+		beforeEach(() => {
+			strategy = new MultiSearchReplaceDiffStrategy()
+		})
+
+		it("should correctly strip line numbers from the last line in SEARCH and REPLACE blocks", async () => {
+			// This test case reproduces the issue from GitHub issue #8020
+			// where the last line with a line number wasn't being stripped correctly
+			// Note: The original content should NOT have line numbers
+			const originalContent = `                                                ContactRelaEnum.MS.name(), addressList, contactStatusMap, SensitiveType.ADDRESS, curSector);
+			                     }
+			             }
+			             List<ContactInfoItemResp> addressInfoList = new ArrayList<>(CollectionUtils.size(repairInfoList) > 10 ? 10
+			                             : CollectionUtils.size(repairInfoList) + CollectionUtils.size(homeAddressInfoList)
+			                                             + CollectionUtils.size(idNoAddressInfoList) + CollectionUtils.size(workAddressInfoList)
+			                                             + CollectionUtils.size(personIdentityInfoList));`
+
+			const diffContent = `<<<<<<< SEARCH
+1473 |                                                 ContactRelaEnum.MS.name(), addressList, contactStatusMap, SensitiveType.ADDRESS, curSector);
+1474 |                         }
+1475 |                 }
+1476 |                 List<ContactInfoItemResp> addressInfoList = new ArrayList<>(CollectionUtils.size(repairInfoList) > 10 ? 10
+1477 |                                 : CollectionUtils.size(repairInfoList) + CollectionUtils.size(homeAddressInfoList)
+1478 |                                                 + CollectionUtils.size(idNoAddressInfoList) + CollectionUtils.size(workAddressInfoList)
+1479 |                                                 + CollectionUtils.size(personIdentityInfoList));
+=======
+1473 |                                                 ContactRelaEnum.MS.name(), addressList, contactStatusMap, SensitiveType.ADDRESS, curSector);
+1474 |                         }
+1475 |                 }
+1476 |                 
+1477 |                 // 
+1478 |                 if (isAddressDisplayOptimizeEnabled()) {
+1479 |                     homeAddressInfoList = filterAddressesByThreeYearRule(homeAddressInfoList);
+1480 |                     personIdentityInfoList = filterAddressesByThreeYearRule(personIdentityInfoList);
+1481 |                     idNoAddressInfoList = filterAddressesByThreeYearRule(idNoAddressInfoList);
+1482 |                     workAddressInfoList = filterAddressesByThreeYearRule(workAddressInfoList);
+1483 |                 }
+1484 |                 
+1485 |                 List<ContactInfoItemResp> addressInfoList = new ArrayList<>(CollectionUtils.size(repairInfoList) > 10 ? 10
+1486 |                                 : CollectionUtils.size(repairInfoList) + CollectionUtils.size(homeAddressInfoList)
+1487 |                                                 + CollectionUtils.size(idNoAddressInfoList) + CollectionUtils.size(workAddressInfoList)
+1488 |                                                 + CollectionUtils.size(personIdentityInfoList));
+>>>>>>> REPLACE`
+
+			const result = await strategy.applyDiff(originalContent, diffContent)
+			if (!result.success) {
+				console.error("Test failed with error:", result.error || result.failParts)
+			}
+			expect(result.success).toBe(true)
+			if (result.success) {
+				const expectedContent = `                                                ContactRelaEnum.MS.name(), addressList, contactStatusMap, SensitiveType.ADDRESS, curSector);
+                        }
+                }
+                
+                // 
+                if (isAddressDisplayOptimizeEnabled()) {
+                    homeAddressInfoList = filterAddressesByThreeYearRule(homeAddressInfoList);
+                    personIdentityInfoList = filterAddressesByThreeYearRule(personIdentityInfoList);
+                    idNoAddressInfoList = filterAddressesByThreeYearRule(idNoAddressInfoList);
+                    workAddressInfoList = filterAddressesByThreeYearRule(workAddressInfoList);
+                }
+                
+                List<ContactInfoItemResp> addressInfoList = new ArrayList<>(CollectionUtils.size(repairInfoList) > 10 ? 10
+                                : CollectionUtils.size(repairInfoList) + CollectionUtils.size(homeAddressInfoList)
+                                                + CollectionUtils.size(idNoAddressInfoList) + CollectionUtils.size(workAddressInfoList)
+                                                + CollectionUtils.size(personIdentityInfoList));`
+				expect(result.content).toBe(expectedContent)
+			}
+		})
+
+		it("should handle Windows CRLF line endings with line numbers at the last line", async () => {
+			// Test with Windows-style CRLF line endings
+			const originalContent = "line 1\r\nline 2\r\nline 3"
+			const diffContent = `<<<<<<< SEARCH
+1 | line 1
+2 | line 2
+3 | line 3
+=======
+1 | line 1
+2 | modified line 2
+3 | line 3
+>>>>>>> REPLACE`
+
+			const result = await strategy.applyDiff(originalContent, diffContent)
+			expect(result.success).toBe(true)
+			if (result.success) {
+				expect(result.content).toBe("line 1\r\nmodified line 2\r\nline 3")
+			}
+		})
+
+		it("should handle single line with line number at the end", async () => {
+			// Simple test case for a single line with line number
+			const originalContent = "some content here"
+			const diffContent = `<<<<<<< SEARCH
+1 | some content here
+=======
+1 | modified content here
+>>>>>>> REPLACE`
+
+			const result = await strategy.applyDiff(originalContent, diffContent)
+			expect(result.success).toBe(true)
+			if (result.success) {
+				expect(result.content).toBe("modified content here")
+			}
+		})
+	})
+})

src/core/diff/strategies/__tests__/multi-search-replace-simple.spec.ts

@@ -0,0 +1,29 @@
+import { MultiSearchReplaceDiffStrategy } from "../multi-search-replace"
+
+describe("MultiSearchReplaceDiffStrategy - Simple Line Number Test", () => {
+	let strategy: MultiSearchReplaceDiffStrategy
+
+	beforeEach(() => {
+		strategy = new MultiSearchReplaceDiffStrategy()
+	})
+
+	it("should handle simple line number stripping", async () => {
+		const originalContent = "line 1\nline 2\nline 3"
+		const diffContent = `<<<<<<< SEARCH
+1 | line 1
+2 | line 2
+3 | line 3
+=======
+1 | line 1
+2 | modified line 2
+3 | line 3
+>>>>>>> REPLACE`
+
+		const result = await strategy.applyDiff(originalContent, diffContent)
+		console.log("Result:", result)
+		expect(result.success).toBe(true)
+		if (result.success) {
+			expect(result.content).toBe("line 1\nmodified line 2\nline 3")
+		}
+	})
+})

src/integrations/misc/extract-text.ts

@@ -163,7 +163,14 @@ export function stripLineNumbers(content: string, aggressive: boolean = false):
 
 	// Join back with original line endings (carriage return (\r) + line feed (\n) or just line feed (\n))
 	const lineEnding = content.includes("\r\n") ? "\r\n" : "\n"
-	return processedLines.join(lineEnding)
+	const result = processedLines.join(lineEnding)
+
+	// Preserve the original trailing newline if it existed
+	// This is important for diffs where the last line might not have a newline
+	if (content.endsWith("\n") || content.endsWith("\r\n")) {
+		return result.endsWith(lineEnding) ? result : result + lineEnding
+	}
+	return result
 }
 
 /**