Better error messages for diffs

Author: mrubens

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
-								if (newContent === false) {
+								const diffResult = this.diffStrategy?.applyDiff(originalContent, diffContent) ?? {
+									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}`)
-									pushToolResult(`Error applying diff to file: ${absolutePath} - contents are out of sync. Try re-reading the relevant lines of the file and applying the diff again.`)
+									const errorDetails = diffResult.details ? `\n\nDetails:\n${JSON.stringify(diffResult.details, null, 2)}` : ''
+									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({