41 lines
1 KiB
TypeScript
41 lines
1 KiB
TypeScript
import type { VFile, VFileData as Data } from 'vfile';
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import type { MarkdownAstroData } from './types.js';
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function isValidAstroData(obj: unknown): obj is MarkdownAstroData {
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if (typeof obj === 'object' && obj !== null && obj.hasOwnProperty('frontmatter')) {
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const { frontmatter } = obj as any;
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try {
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// ensure frontmatter is JSON-serializable
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JSON.stringify(frontmatter);
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} catch {
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return false;
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}
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return typeof frontmatter === 'object' && frontmatter !== null;
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}
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return false;
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}
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export class InvalidAstroDataError extends TypeError {}
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export function safelyGetAstroData(vfileData: Data): MarkdownAstroData | InvalidAstroDataError {
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const { astro } = vfileData;
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if (!astro || !isValidAstroData(astro)) {
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return new InvalidAstroDataError();
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}
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return astro;
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}
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export function toRemarkInitializeAstroData({
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userFrontmatter,
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}: {
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userFrontmatter: Record<string, any>;
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}) {
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return () =>
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function (tree: any, vfile: VFile) {
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if (!vfile.data.astro) {
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vfile.data.astro = { frontmatter: userFrontmatter };
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}
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};
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}
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