Method handleImportAtRule

lib/css/CssParser.js:2616–2813

(at, topLevel)

		 * @param {boolean} topLevel whether the rule is at the stylesheet top level
		 */
		const handleImportAtRule = (at, topLevel) => {
			if (!this.options.import) return;
			if (!topLevel || !allowImport) {
				this._emitWarning(
					state,
					"Any '@import' rules must precede all other rules",
					locConverter,
					A.start(at),
					A.nameEnd(at)
				);
				return;
			}
			const importStart = A.start(at);
			const importNameEnd = A.nameEnd(at);
			// We only accept `;`-terminated @import; block / EOF / `}` ends are silent bails.
			if (source.charCodeAt(A.end(at)) !== CC_SEMICOLON) return;

			// Walk the prelude in spec order (URL → layer? → supports? → media query); anything else joins the media query.
			const { urlNode, layerNode, supportsNode } = parseImportPrelude(
				A.prelude(at)
			);

			const semi = A.end(at) + 1; // position past `;`

			if (!urlNode || (A.type(urlNode) === NodeType.Ident && !isModules)) {
				this._emitWarning(
					state,
					`Expected URL in '${input.slice(importStart, semi)}'`,
					locConverter,
					importStart,
					semi
				);
				// A malformed `@import` still emits orphan url() deps from its prelude — flag it so the value visitors enable url().
				currentUrlRecovery = true;
				return;
			}

			/** @type {string} */
			let url;
			if (A.type(urlNode) === NodeType.Ident) {
				// URL given as identifier — resolve via CSS Modules `@value`.
				const identName = A.value(urlNode);
				const def = icssDefinitions.get(identName);
				if (!def) {
					this._emitWarning(
						state,
						`Unknown '@value' identifier '${identName}' in '${input.slice(
							importStart,
							semi
						)}'`,
						locConverter,
						importStart,
						semi
					);
					// Drop the whole at-rule so the unresolved identifier isn't substituted into the output.
					const dep = new ConstDependency("", [importStart, semi]);
					module.addPresentationalDependency(dep);
					return;