1 files changed, 108 insertions, 0 deletions
diff --git a/packages/integrations/mdx/src/utils.ts b/packages/integrations/mdx/src/utils.ts
new file mode 100644
index 000000000..7dcd4a14c
--- /dev/null
+++ b/packages/integrations/mdx/src/utils.ts
@@ -0,0 +1,108 @@
+import { parseFrontmatter } from '@astrojs/markdown-remark';
+import type { Options as AcornOpts } from 'acorn';
+import { parse } from 'acorn';
+import type { AstroConfig, AstroIntegrationLogger, SSRError } from 'astro';
+import { bold } from 'kleur/colors';
+import type { MdxjsEsm } from 'mdast-util-mdx';
+import type { PluggableList } from 'unified';
+
+function appendForwardSlash(path: string) {
+	return path.endsWith('/') ? path : path + '/';
+}
+
+export interface FileInfo {
+	fileId: string;
+	fileUrl: string;
+}
+
+/** @see 'vite-plugin-utils' for source */
+export function getFileInfo(id: string, config: AstroConfig): FileInfo {
+	const sitePathname = appendForwardSlash(
+		config.site ? new URL(config.base, config.site).pathname : config.base,
+	);
+
+	// Try to grab the file's actual URL
+	let url: URL | undefined = undefined;
+	try {
+		url = new URL(`file://${id}`);
+	} catch {}
+
+	const fileId = id.split('?')[0];
+	let fileUrl: string;
+	const isPage = fileId.includes('/pages/');
+	if (isPage) {
+		fileUrl = fileId.replace(/^.*?\/pages\//, sitePathname).replace(/(?:\/index)?\.mdx$/, '');
+	} else if (url?.pathname.startsWith(config.root.pathname)) {
+		fileUrl = url.pathname.slice(config.root.pathname.length);
+	} else {
+		fileUrl = fileId;
+	}
+
+	if (fileUrl && config.trailingSlash === 'always') {
+		fileUrl = appendForwardSlash(fileUrl);
+	}
+	return { fileId, fileUrl };
+}
+
+/**
+ * Match YAML exception handling from Astro core errors
+ * @see 'astro/src/core/errors.ts'
+ */
+export function safeParseFrontmatter(code: string, id: string) {
+	try {
+		return parseFrontmatter(code, { frontmatter: 'empty-with-spaces' });
+	} catch (e: any) {
+		if (e.name === 'YAMLException') {
+			const err: SSRError = e;
+			err.id = id;
+			err.loc = { file: e.id, line: e.mark.line + 1, column: e.mark.column };
+			err.message = e.reason;
+			throw err;
+		} else {
+			throw e;
+		}
+	}
+}
+
+export function jsToTreeNode(
+	jsString: string,
+	acornOpts: AcornOpts = {
+		ecmaVersion: 'latest',
+		sourceType: 'module',
+	},
+): MdxjsEsm {
+	return {
+		type: 'mdxjsEsm',
+		value: '',
+		data: {
+			// @ts-expect-error `parse` return types is incompatible but it should work in runtime
+			estree: {
+				...parse(jsString, acornOpts),
+				type: 'Program',
+				sourceType: 'module',
+			},
+		},
+	};
+}
+
+export function ignoreStringPlugins(plugins: any[], logger: AstroIntegrationLogger): PluggableList {
+	let validPlugins: PluggableList = [];
+	let hasInvalidPlugin = false;
+	for (const plugin of plugins) {
+		if (typeof plugin === 'string') {
+			logger.warn(`${bold(plugin)} not applied.`);
+			hasInvalidPlugin = true;
+		} else if (Array.isArray(plugin) && typeof plugin[0] === 'string') {
+			logger.warn(`${bold(plugin[0])} not applied.`);
+			hasInvalidPlugin = true;
+		} else {
+			validPlugins.push(plugin);
+		}
+	}
+	if (hasInvalidPlugin) {
+		logger.warn(
+			`To inherit Markdown plugins in MDX, please use explicit imports in your config instead of "strings." See Markdown docs: https://docs.astro.build/en/guides/markdown-content/#markdown-plugins`,
+		);
+	}
+	return validPlugins;
+}