Function fetchFromURL

lib/util/extractSourceMap.js:148–213

* Fetch source content from URL * @param {ReadResource} readResource The read resource function * @param {string} context context directory * @param {string} url source URL * @param {string=} sourceRoot source root directory * @param {boolean=} skipReading whether to skip reading file content

(
	readResource,
	context,
	url,
	sourceRoot,
	skipReading = false
)

 * @returns {Promise<{ sourceURL: string, sourceContent?: StringOrBuffer }>} source content promise
 */
async function fetchFromURL(
	readResource,
	context,
	url,
	sourceRoot,
	skipReading = false
) {
	// 1. It's an absolute url and it is not `windows` path like `C:\dir\file`
	if (isURL(url)) {
		// eslint-disable-next-line n/no-deprecated-api
		const { protocol } = urlUtils.parse(url);
		if (protocol === "data:") {
			const sourceContent = skipReading ? "" : await readResource(url);

			return { sourceURL: "", sourceContent };
		}

		if (protocol === "file:") {
			const pathFromURL = urlUtils.fileURLToPath(url);
			const sourceURL = path.normalize(pathFromURL);
			const sourceContent = skipReading ? "" : await readResource(sourceURL);

			return { sourceURL, sourceContent };
		}

		const sourceContent = skipReading ? "" : await readResource(url);
		return { sourceURL: url, sourceContent };
	}

	// 3. Absolute path
	if (isAbsolute(url)) {
		let sourceURL = path.normalize(url);

		/** @type {undefined | StringOrBuffer} */
		let sourceContent;

		if (!skipReading) {
			/** @type {string[]} */
			const possibleRequests = [sourceURL];

			if (url.startsWith("/")) {
				possibleRequests.push(
					getAbsolutePath(context, sourceURL.slice(1), sourceRoot || "")
				);
			}

			const result = await fetchPathsFromURL(readResource, possibleRequests);

			sourceURL = result.path;
			sourceContent = result.data;
		}

		return { sourceURL, sourceContent };
	}

	// 4. Relative path
	const sourceURL = getAbsolutePath(context, url, sourceRoot || "");
	/** @type {undefined | StringOrBuffer} */