{"record":{"id":"b56eb6e3e099e319","repo":"vxcontrol/pentagi","slug":"diff-is-required-and-cannot-be-empty","errorCode":null,"errorMessage":"diff is required and cannot be empty","messagePattern":"diff is required and cannot be empty","errorType":"validation","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"backend/pkg/tools/terminal.go","lineNumber":507,"sourceCode":"\t\tAllowOverwriteDirWithFile: true,\n\t})\n\tif err != nil {\n\t\treturn fmt.Errorf(\"container file transfer failed: %w\", err)\n\t}\n\n\treturn nil\n}\n\n// EditFile applies a unified diff to the file at path: it reads the current\n// content, applies the diff to it entirely in memory (see applyUnifiedDiff),\n// and only if every hunk applied cleanly writes the result back - a diff\n// that doesn't fully apply leaves the file untouched.\nfunc (t *terminal) EditFile(ctx context.Context, flowID int64, path, diffText string) (string, error) {\n\tif path == \"\" {\n\t\treturn \"\", fmt.Errorf(\"path is required and cannot be empty\")\n\t}\n\tif strings.TrimSpace(diffText) == \"\" {\n\t\treturn \"\", fmt.Errorf(\"diff is required and cannot be empty\")\n\t}\n\n\tcurrent, err := t.readFileFromContainer(ctx, flowID, path)\n\tif err != nil {\n\t\treturn \"\", fmt.Errorf(\"failed to read current content of %s before editing: %w\", path, err)\n\t}\n\n\tnewContent, hunksApplied, err := ApplyUnifiedDiff(current, diffText)\n\tif err != nil {\n\t\treturn \"\", fmt.Errorf(\"failed to apply diff to %s: %w\", path, err)\n\t}\n\n\tif err := t.writeFileToContainer(ctx, flowID, path, newContent); err != nil {\n\t\treturn \"\", fmt.Errorf(\"failed to write edited content of %s: %w\", path, err)\n\t}\n\n\tsuccessMsg := fmt.Sprintf(\"Applied %d diff hunk(s) to %s (%d -> %d bytes)\", hunksApplied, path, len(current), len(newContent))\n\tstyledMsg := fmt.Sprintf(\"%s%s%s%s\", ansiColorSystemMsg, successMsg, ansiColorReset, ansiLineTerminator)","sourceCodeStart":489,"sourceCodeEnd":525,"githubUrl":"https://github.com/vxcontrol/pentagi/blob/ea665308baaff015b226f308438a68d929d0f29b/backend/pkg/tools/terminal.go#L489-L525","documentation":"Input validation error from EditFile (backend/pkg/tools/terminal.go): the unified 'diff' argument is empty or whitespace-only, so no edit can be applied. The LLM/tool caller must supply a non-empty unified diff; the file is left untouched.","triggerScenarios":"Calling EditFile with diffText=\"\" or a string containing only spaces/newlines — e.g. the model emitted no diff body, or the caller passed the wrong variable.","commonSituations":"LLM tool call where the model produced an explanation but no diff; upstream diff generation returned an empty string on no-change; callers using EditFile to 'touch' a file instead of WriteFile.","solutions":["Provide a valid unified diff (---/+++ headers plus @@ hunks) in the diffText argument","If no changes are needed, do not call EditFile at all — skip the call or use WriteFile for full rewrites","Validate diffText is non-blank in the caller before dispatching (strings.TrimSpace check)","If the model repeatedly emits empty diffs, improve the tool description/prompt requiring a unified diff body"],"exampleFix":"// before\nmsg, err := term.EditFile(ctx, flowID, path, diff)\n// after\nif strings.TrimSpace(diff) == \"\" {\n    return fmt.Errorf(\"refusing to call EditFile with empty diff for %s\", path)\n}\nmsg, err := term.EditFile(ctx, flowID, path, diff)","handlingStrategy":"validation","validationCode":"if strings.TrimSpace(diffText) == \"\" {\n    return fmt.Errorf(\"diffText must contain a unified diff before calling edit_file\")\n}\nif !strings.Contains(diffText, \"@@\") {\n    return fmt.Errorf(\"diffText does not look like a unified diff (no hunk headers)\")\n}","typeGuard":"func nonBlank(s string) bool { return strings.TrimSpace(s) != \"\" }","tryCatchPattern":"msg, err := term.EditFile(ctx, flowID, path, diff)\nif err != nil && strings.Contains(err.Error(), \"diff is required\") {\n    return fmt.Errorf(\"edit_file called with empty diff; skipping no-op edit\")\n}","preventionTips":["Skip EditFile entirely when no changes are needed","Instruct agents to emit complete unified diffs with headers and hunks","Validate diff shape (---/+++/@@) before dispatching"],"tags":["validation","input","diff","edit-file"],"backgroundTag":"missing-required-argument","analyzedSha":"ea665308baaff015b226f308438a68d929d0f29b","analyzedAt":"2026-09-01T14:16:31.421Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}