Function parseMediaQuery

packages/css-data/src/parse-css.ts:1135–1194

(
  mediaQuery: string
)

};

export const parseMediaQuery = (
  mediaQuery: string
): undefined | ParsedBreakpoint => {
  const ast = csstree.parse(mediaQuery, { context: "mediaQuery" });
  let minWidth: undefined | number;
  let maxWidth: undefined | number;
  let currentWidthProperty: undefined | "minWidth" | "maxWidth";
  const otherFeatures: string[] = [];

  csstree.walk(ast, (node) => {
    if (node.type === "Feature") {
      if (node.name === "min-width") {
        currentWidthProperty = "minWidth";
      } else if (node.name === "max-width") {
        currentWidthProperty = "maxWidth";
      } else {
        currentWidthProperty = undefined;
        // Capture any other media feature as custom condition
        const generated = csstree.generate(node);
        // Remove outer parentheses if present
        let cleaned =
          generated.startsWith("(") && generated.endsWith(")")
            ? generated.slice(1, -1)
            : generated;
        // Normalize whitespace: remove spaces around colons for consistency
        cleaned = cleaned.replace(/\s*:\s*/g, ":");
        otherFeatures.push(cleaned);
      }
    }
    if (node.type === "Dimension" && node.unit === "px") {
      const value = Number(node.value);
      if (currentWidthProperty === "minWidth") {
        minWidth = value;
      } else if (currentWidthProperty === "maxWidth") {
        maxWidth = value;
      }
      currentWidthProperty = undefined;
    }
  });

  const condition =
    otherFeatures.length > 0 ? otherFeatures.join(" and ") : undefined;

  const hasWidth = minWidth !== undefined || maxWidth !== undefined;

  // If there's a custom condition and no width, return only condition
  if (condition !== undefined && !hasWidth) {
    return { condition };
  }

  if (!hasWidth && condition === undefined) {
    return;
  }

  return {
    ...(minWidth !== undefined ? { minWidth } : {}),
    ...(maxWidth !== undefined ? { maxWidth } : {}),
    ...(condition !== undefined ? { condition } : {}),