Method emitUrlFunction

lib/css/CssParser.js:2539–2609

(fn, fname)

		 * @param {string} fname the function name, lower-cased
		 */
		const emitUrlFunction = (fn, fname) => {
			if (fname === "url" || fname === "src") {
				// Quoted `url("…")` / `src("…")`: first non-whitespace value must be the string token.
				const first = A.children(fn)[nextNonWhitespace(A.children(fn), 0)];
				if (!first || A.type(first) !== NodeType.String) return;
				const string = /** @type {Token} */ (first);
				if (
					webpackIgnored(
						[lastTokenEndForComments, A.start(fn)],
						A.start(string),
						A.end(string)
					)
				) {
					return;
				}
				const value = normalizeUrl(
					input.slice(A.start(string) + 1, A.end(string) - 1),
					true
				);
				// Ignore `url()`, `url('')` and `url("")`, they are valid by spec
				if (value.length === 0) return;
				const dep = new CssUrlDependency(
					value,
					[A.start(string), A.end(string)],
					"string"
				);
				setDepLoc(dep, A.start(string), A.end(string));
				module.addDependency(dep);
				module.addCodeGenerationDependency(dep);
			} else if (IMAGE_SET_FUNCTION.test(fname)) {
				// `image-set(…)`: each comma segment's first string is the URL; advance the magic-comment fence per string.
				lastTokenEndForComments = A.nameEnd(fn) + 1;
				let prevStringEnd = A.start(fn);
				let firstInSegment = true;
				for (const cv of A.children(fn)) {
					if (A.type(cv) === NodeType.Comma) {
						firstInSegment = true;
						continue;
					}
					if (A.type(cv) === NodeType.Whitespace) continue;
					const wasFirst = firstInSegment;
					firstInSegment = false;
					if (!wasFirst || A.type(cv) !== NodeType.String) continue;
					const string = /** @type {Token} */ (cv);
					const start = prevStringEnd;
					prevStringEnd = A.end(string);
					const value = normalizeUrl(
						input.slice(A.start(string) + 1, A.end(string) - 1),
						true
					);
					if (value.length === 0) continue;
					if (
						webpackIgnored(
							[start, A.end(string)],
							A.start(string),
							A.end(string)
						)
					) {