visitors.Rule() — svelte Function Reference

Source Code

packages/svelte/src/compiler/phases/3-transform/css/index.js lines 138–197

	Rule(node, { state, next, visit, path }) {
		if (state.minify) {
			remove_preceding_whitespace(node.start, state);
			remove_preceding_whitespace(node.block.end - 1, state);
		}

		// keep empty rules in dev, because it's convenient to
		// see them in devtools
		if (!dev && is_empty(node, is_in_global_block(path))) {
			if (state.minify) {
				state.code.remove(node.start, node.end);
			} else {
				state.code.prependRight(node.start, '/* (empty) ');
				state.code.appendLeft(node.end, '*/');
				escape_comment_close(node, state.code);
			}

			return;
		}

		if (!is_used(node) && !is_in_global_block(path)) {
			if (state.minify) {
				state.code.remove(node.start, node.end);
			} else {
				state.code.prependRight(node.start, '/* (unused) ');
				state.code.appendLeft(node.end, '*/');
				escape_comment_close(node, state.code);
			}

			return;
		}

		if (node.metadata.is_global_block) {
			const selector = node.prelude.children[0];

			if (
				node.prelude.children.length === 1 &&
				selector.children.length === 1 &&
				selector.children[0].selectors.length === 1
			) {
				// `:global {...}`
				if (state.minify) {
					state.code.remove(node.start, node.block.start + 1);
					state.code.remove(node.block.end - 1, node.end);
				} else {
					state.code.prependRight(node.start, '/* ');
					state.code.appendLeft(node.block.start + 1, '*/');

					state.code.prependRight(node.block.end - 1, '/*');
					state.code.appendLeft(node.block.end, '*/');
				}

				// don't recurse into selectors but visit the body
				visit(node.block);
				return;
			}
		}

		next();
	},