getConfigAlias() — astro Function Reference

Architecture documentation for the getConfigAlias() function in index.ts from the astro codebase.

Function typescript CoreAstro RenderingEngine called by 1

Entity Profile

CoreAstro→ RenderingEngine→ getConfigAlias() — astro Function Reference

Dependency Diagram

graph TD
  1ba10327_e048_1b04_3323_048810802c61["getConfigAlias()"]
  7996ca89_cb81_c0ba_4ce2_f1ad1a93890c["index.ts"]
  1ba10327_e048_1b04_3323_048810802c61 -->|defined in| 7996ca89_cb81_c0ba_4ce2_f1ad1a93890c
  41c9f435_8602_aa44_336c_21df75b6be30["configAliasVitePlugin()"]
  41c9f435_8602_aa44_336c_21df75b6be30 -->|calls| 1ba10327_e048_1b04_3323_048810802c61
  style 1ba10327_e048_1b04_3323_048810802c61 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

packages/astro/src/vite-plugin-config-alias/index.ts lines 14–68

const getConfigAlias = (settings: AstroSettings): Alias[] | null => {
	const { tsConfig, tsConfigPath } = settings;
	if (!tsConfig || !tsConfigPath || !tsConfig.compilerOptions) return null;

	const { baseUrl, paths } = tsConfig.compilerOptions as CompilerOptions;

	// If paths exist but baseUrl doesn't, default to "." (tsconfig directory)
	const effectiveBaseUrl = baseUrl ?? (paths ? '.' : undefined);
	if (!effectiveBaseUrl) return null;

	// resolve the base url from the configuration file directory
	const resolvedBaseUrl = path.resolve(path.dirname(tsConfigPath), effectiveBaseUrl);

	const aliases: Alias[] = [];

	// compile any alias expressions and push them to the list
	if (paths) {
		for (const [alias, values] of Object.entries(paths)) {
			/** Regular Expression used to match a given path. */
			const find = new RegExp(
				`^${[...alias]
					.map((segment) =>
						segment === '*' ? '(.+)' : segment.replace(/[\\^$*+?.()|[\]{}]/, '\\$&'),
					)
					.join('')}$`,
			);

			for (const value of values) {
				/** Internal index used to calculate the matching id in a replacement. */
				let matchId = 0;
				/** String used to replace a matched path. */
				const replacement = [...normalizePath(path.resolve(resolvedBaseUrl, value))]
					.map((segment) => (segment === '*' ? `$${++matchId}` : segment === '$' ? '$$' : segment))
					.join('');

				aliases.push({ find, replacement });
			}
		}
	}

	// compile the baseUrl expression and push it to the list
	// - `baseUrl` changes the way non-relative specifiers are resolved
	// - if `baseUrl` exists then all non-relative specifiers are resolved relative to it
	// - only add this if an explicit baseUrl was provided (not the default)
	if (baseUrl) {
		aliases.push({
			find: /^(?!\.*\/|\.*$|\w:)(.+)$/,
			replacement: `${[...normalizePath(resolvedBaseUrl)]
				.map((segment) => (segment === '$' ? '$$' : segment))
				.join('')}/$1`,
		});
	}

	return aliases;
};