{"record":{"id":"85d8a622efa862f9","repo":"yorukot/superfile","slug":"failure-while-extracting-content-w","errorCode":null,"errorMessage":"failure while extracting content : %w","messagePattern":"failure while extracting content : %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"src/internal/validation.go","lineNumber":386,"sourceCode":"\t// TODO: programatically ensure that only one of them is open at a time\n\t// We may need some sort of overlay model management\n\tif m.IsOverlayModelOpen() {\n\t\tfinalRender := m.updateRenderForOverlay(mainRender)\n\t\tif err := validateRender(finalRender, m.fullHeight, m.fullWidth, false); err != nil {\n\t\t\treturn fmt.Errorf(\"model rendering failures : %w\", err)\n\t\t}\n\n\t\t// TODO: Add validations for overlay models\n\t}\n\n\treturn nil\n}\n\n// Inclusive\nfunc (m *model) validateComponentPlacement(lines []string, pos compPosition, border bool) error {\n\textractedLines, err := m.extractComponent(lines, pos)\n\tif err != nil {\n\t\treturn fmt.Errorf(\"failure while extracting content : %w\", err)\n\t}\n\n\tcntRow := pos.endRow - pos.stRow + 1\n\tcntCol := pos.endCol - pos.stCol + 1\n\textractedOut := strings.Join(extractedLines, \"\\n\")\n\tif err := validateRender(extractedOut, cntRow, cntCol, border); err != nil {\n\t\treturn fmt.Errorf(\"failure in extracted content : %w\", err)\n\t}\n\treturn nil\n}\n\n// Inclusive\nfunc (m *model) extractComponent(lines []string, pos compPosition) ([]string, error) {\n\tif 0 > pos.stRow || pos.stRow > pos.endRow || pos.endRow >= len(lines) {\n\t\treturn nil, fmt.Errorf(\"invalid row range [%v, %v], line count : %v\",\n\t\t\tpos.stRow, pos.endRow, len(lines))\n\t}\n\tfirstLineWidth := ansi.StringWidth(lines[0])","sourceCodeStart":368,"sourceCodeEnd":404,"githubUrl":"https://github.com/yorukot/superfile/blob/b72f550bc6e75913f48eb49fdd258e1a2df2fe88/src/internal/validation.go#L368-L404","documentation":"validateComponentPlacement extracts the region of rendered lines at the given component position and validates it. This error wraps a failure from m.extractComponent, meaning the requested region could not be cut out of the rendered lines. It typically indicates the computed component position (rows/cols) does not fit within the rendered content.","triggerScenarios":"validateFinalRender computes a compPosition whose stRow/endRow or stCol/endCol fall outside the rendered lines (e.g., component rendered smaller than expected), causing extractComponent to fail.","commonSituations":"Component renders fewer lines/columns than the model expects (terminal width changes, wrapping differences, ANSI-styled content narrower than assumed); off-by-one in position calculation.","solutions":["Log pos and len(lines)/width at the call site to see which bound is violated","Clamp pos.stRow/stCol and endRow/endCol to the actual rendered dimensions before validating","Re-render the component and recompute its position after any terminal resize","Check whether the component output is empty or shorter than the allocated area"],"exampleFix":"// before\nextractedLines, err := m.extractComponent(lines, pos)\n// after\nif pos.endRow >= len(lines) || pos.endCol >= ansi.StringWidth(lines[0]) {\n\treturn fmt.Errorf(\"component position %v exceeds rendered area\", pos)\n}\nextractedLines, err := m.extractComponent(lines, pos)","handlingStrategy":"validation","validationCode":"func validPos(lines []string, pos compPosition) bool {\n\treturn pos.stRow >= 0 && pos.stRow <= pos.endRow && pos.endRow < len(lines) &&\n\t\tpos.stCol >= 0 && pos.stCol <= pos.endCol && pos.endCol < ansi.StringWidth(lines[0])\n}","typeGuard":null,"tryCatchPattern":"if err := m.validateComponentPlacement(lines, pos, border); err != nil {\n\tlog.Printf(\"placement failed at %v: %v\", pos, err)\n\treturn err // or re-render and retry once\n}","preventionTips":["Recompute compPosition from freshly rendered content after any resize","Use ansi.StringWidth for all width math, never len()","Clamp positions to actual rendered dimensions before validation","Add unit tests for components rendered at minimum terminal size"],"tags":["go","validation","rendering","layout"],"backgroundTag":"render-region-out-of-bounds","analyzedSha":"b72f550bc6e75913f48eb49fdd258e1a2df2fe88","analyzedAt":"2026-09-01T04:38:08.254Z","contentChangedAt":null,"schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}