Function buildRendererStructuralProbe

src/commands/repaint/repaint.ts:105–180

(
  ink: InkLike | undefined,
  tmuxPane: { text?: string; paneHeight?: number },
)

}

function buildRendererStructuralProbe(
  ink: InkLike | undefined,
  tmuxPane: { text?: string; paneHeight?: number },
): RendererStructuralProbe {
  const frontRows = screenRows(ink?.frontFrame?.screen)
  const logicalFrontRows = screenRows(ink?.logicalFrontFrame?.screen)
  const backRows = screenRows(ink?.backFrame?.screen)
  const logicalBackRows = screenRows(ink?.logicalBackFrame?.screen)

  // capture-pane may include scrollback plus the full visible pane. The app
  // frame is painted from the viewport top and may be shorter than the pane,
  // so compare it with the top of the visible pane, not the last N rows.
  const tmuxVisibleRows = selectObservedFrameRows(
    tmuxPane.text,
    frontRows.length,
    tmuxPane.paneHeight,
  )

  const structuralDiffs: StructuralDiff[] = []

  function addDiffs(label: string, diffs: RowDiff[]) {
    for (const diff of diffs) {
      structuralDiffs.push({
        source: label,
        row: diff.row,
        expected: diff.expected,
        actual: diff.actual,
      })
    }
  }

  const frontVsTmux = compareRows(frontRows, tmuxVisibleRows)
  addDiffs('tmux_vs_front', frontVsTmux)

  const logicalFrontVsFront = compareRows(
    logicalFrontRows.slice(-frontRows.length),
    frontRows,
  )
  addDiffs('logical_vs_front', logicalFrontVsFront)

  const logicalBackVsBack = compareRows(
    logicalBackRows.slice(-backRows.length),
    backRows,
  )
  addDiffs('logical_vs_back', logicalBackVsBack)

  const hasFrontTmuxDiff = frontVsTmux.length > 0
  const hasLogicalFrontDiff = logicalFrontVsFront.length > 0
  const hasLogicalBackDiff = logicalBackVsBack.length > 0

  const verdict: RendererStructuralProbe['verdict'] =
    !ink && !tmuxPane.text
      ? 'not_observed'
      : !hasFrontTmuxDiff && !hasLogicalFrontDiff && !hasLogicalBackDiff
        ? 'clean'
        : hasLogicalFrontDiff
          ? 'logical_corrupt'
          : hasLogicalBackDiff