feat: Initial clean release of CHM

packages/tools/website/utils/frontMatter.ts

@@ -0,0 +1,102 @@
+import * as yaml from 'js-yaml';
+
+import moment from 'moment';
+
+export interface FrontMatter {
+	created?: Date;
+	updated?: Date;
+	source_url?: string;
+	forum_url?: string;
+	tweet?: string;
+
+	// Docusaurus
+	sidebar_label?: string;
+	sidebar_position?: number;
+	date?: string;
+	title?: string;
+	description?: string;
+	image?: string;
+}
+
+export interface MarkdownAndFrontMatter {
+	doc: string;
+	header: FrontMatter;
+}
+
+export const stripOffFrontMatter = (md: string): MarkdownAndFrontMatter => {
+	if (md.indexOf('---') !== 0) return { doc: md, header: {} };
+
+	let state = 'start';
+	const lines = md.split('\n');
+	const docLines: string[] = [];
+	const headerLines: string[] = [];
+
+	for (const line of lines) {
+		if (state === 'start') {
+			if (line !== '---') throw new Error('Expected front matter block to start with "---"');
+			state = 'in';
+			continue;
+		}
+
+		if (state === 'in') {
+			if (line === '---') {
+				state = 'out';
+				continue;
+			}
+
+			const propLine = line.trim();
+			headerLines.push(propLine);
+		}
+
+		if (state === 'out') {
+			if (line.trim()) state = 'doc';
+		}
+
+		if (state === 'doc') {
+			docLines.push(line);
+		}
+	}
+
+	if (state !== 'doc') throw new Error('Front matter block was not closed with "---"');
+
+	const header = yaml.load(headerLines.join('\n'), { schema: yaml.FAILSAFE_SCHEMA }) as FrontMatter;
+
+	if (header.created) header.created = moment(header.created).toDate();
+	if (header.updated) header.updated = moment(header.updated).toDate();
+	if ('sidebar_position' in header) header.sidebar_position = Number(header.sidebar_position);
+
+	return { header, doc: docLines.join('\n') };
+};
+
+// ---
+// created: 2021-07-05T09:42:47.000+00:00
+// source_url: https://www.patreon.com/posts/any-ideas-for-53317699
+// ---
+
+const formatFrontMatterValue = (key: string, value: FrontMatter[keyof FrontMatter]) => {
+	if (['created', 'updated'].includes(key)) {
+		return moment((value as Date)).toISOString();
+	} else {
+		return value.toString();
+	}
+};
+
+export const compileWithFrontMatter = (md: MarkdownAndFrontMatter): string => {
+	const output: string[] = [];
+
+	if (Object.keys(md.header).length) {
+		const header: Record<string, string> = {};
+		for (const [key, value] of Object.entries(md.header)) {
+			header[key] = formatFrontMatterValue(key, value);
+		}
+		const headerString = yaml.dump(header, { noCompatMode: true, schema: yaml.FAILSAFE_SCHEMA, lineWidth: 100000 });
+		output.push('---');
+		output.push(headerString.trim());
+		output.push('---');
+		output.push('');
+	}
+
+	output.push(md.doc);
+
+	return output.join('\n');
+};