@mui/internal-docs-infra/CodeHighlighter/buildStringFallback.d.mts

MUI Infra - internal documentation creation tools.

import type { SourceComments, SourceEnhancers } from "./types.mjs";
import { type FallbackNode } from "./fallbackFormat.mjs";
export interface StringFallbackResult {
  /** Compact, windowed fallback frames (text only — `.line` spans stripped). */
  fallback: FallbackNode[];
  /** Total source lines. */
  totalLines: number;
  /** Lines visible in the collapsed window (the sum of visible frame sizes). */
  focusedLines: number;
  /** Whether the enhanced frame structure has hidden content to expand into. */
  collapsible: boolean;
}
/**
 * Derive a *windowed* fallback for a plain-string source by running the same
 * `sourceEnhancers` the live render uses over a cheap line-guttered HAST
 * (`parsePlainText` — gutters, no syntax highlighting). The inline-string
 * fallback path otherwise wraps the whole source in one un-windowed focus frame,
 * so an oversized / `@focus` / `@highlight` block paints its full text before
 * hydration then snaps to the collapsed window. Running the enhancers here makes
 * the loading frames match the live render, and the resulting `root.data` carries
 * the `totalLines` / `focusedLines` the compact fallback can't preserve.
 *
 * Synchronous by design — it runs at server fallback-prep time inside the
 * (sync) `prepareInitialSource`. An enhancer that returns a promise is skipped
 * (returns `undefined`) so the caller falls back to the naive single-frame wrap
 * rather than blocking; the built-in `enhanceCodeEmphasis` is synchronous, so
 * the common case windows.
 */
export declare function buildStringFallback(source: string, comments: SourceComments | undefined, fileName: string, sourceEnhancers: SourceEnhancers): StringFallbackResult | undefined;