rehypeAnalyzeAstroMetadata() — astro Function Reference

Source Code

packages/astro/src/jsx/rehype.ts lines 19–101

export const rehypeAnalyzeAstroMetadata: RehypePlugin = () => {
	return (tree, file) => {
		// Initial metadata for this MDX file, it will be mutated as we traverse the tree
		const metadata = createDefaultAstroMetadata();

		// Parse imports in this file. This is used to match components with their import source
		const imports = parseImports(tree.children);

		visit(tree, (node) => {
			if (node.type !== 'mdxJsxFlowElement' && node.type !== 'mdxJsxTextElement') return;

			const tagName = node.name;
			if (
				!tagName ||
				!isComponent(tagName) ||
				!(hasClientDirective(node) || hasServerDeferDirective(node))
			)
				return;

			// From this point onwards, `node` is confirmed to be an island component

			// Match this component with its import source
			const matchedImport = findMatchingImport(tagName, imports);
			if (!matchedImport) {
				throw new AstroError({
					...AstroErrorData.NoMatchingImport,
					message: AstroErrorData.NoMatchingImport.message(node.name!),
				});
			}

			// If this is an Astro component, that means the `client:` directive is misused as it doesn't
			// work on Astro components as it's server-side only. Warn the user about this.
			if (matchedImport.path.endsWith('.astro')) {
				const clientAttribute = node.attributes.find(
					(attr) => attr.type === 'mdxJsxAttribute' && attr.name.startsWith('client:'),
				) as MdxJsxAttribute | undefined;
				if (clientAttribute) {
					console.warn(
						`You are attempting to render <${node.name!} ${
							clientAttribute.name
						} />, but ${node.name!} is an Astro component. Astro components do not render in the client and should not have a hydration directive. Please use a framework component for client rendering.`,
					);
				}
			}

			const resolvedPath = resolvePath(matchedImport.path, file.path);

			if (hasClientOnlyDirective(node)) {
				// Add this component to the metadata
				metadata.clientOnlyComponents.push({
					exportName: matchedImport.name,
					localName: '',
					specifier: tagName,
					resolvedPath,
				});
				// Mutate node with additional island attributes
				addClientOnlyMetadata(node, matchedImport, resolvedPath);
			} else if (hasClientDirective(node)) {
				// Add this component to the metadata
				metadata.hydratedComponents.push({
					exportName: '*',
					localName: '',
					specifier: tagName,
					resolvedPath,
				});
				// Mutate node with additional island attributes
				addClientMetadata(node, matchedImport, resolvedPath);
			} else if (hasServerDeferDirective(node)) {
				metadata.serverComponents.push({
					exportName: matchedImport.name,
					localName: tagName,
					specifier: matchedImport.path,
					resolvedPath,
				});
				// Mutate node with additional island attributes
				addServerDeferMetadata(node, matchedImport, resolvedPath);
			}
		});

		// Attach final metadata here, which can later be retrieved by `getAstroMetadata`
		file.data.__astroMetadata = metadata;