Function parseShadow

packages/css-data/src/parse-css-value.ts:480–523

(
  nodes: CssNode[],
  input: string
)

};

const parseShadow = (
  nodes: CssNode[],
  input: string
): ShadowValue | UnparsedValue => {
  // https://drafts.csswg.org/css-borders-4/#box-shadow-position
  let position: "inset" | "outset" = "outset";
  let color: undefined | ColorValue | RgbValue | KeywordValue;
  const units: UnitValue[] = [];
  for (const node of nodes) {
    const item = parseLiteral(node, ["inset"]);
    if (item?.type === "keyword" && item.value === "inset") {
      position = item.value;
    } else if (item?.type === "keyword" && parseColor(item.value)) {
      color = item;
    } else if (item?.type === "color") {
      color = item;
    } else if (item?.type === "rgb") {
      color = item;
    } else if (item?.type === "unit") {
      units.push(item);
    } else {
      return { type: "unparsed", value: input };
    }
  }
  if (units.length < 2) {
    return { type: "unparsed", value: input };
  }
  const shadowValue: ShadowValue = {
    type: "shadow",
    position,
    offsetX: units[0],
    offsetY: units[1],
  };
  if (units.length > 2) {
    shadowValue.blur = units[2];
  }
  if (units.length > 3) {
    shadowValue.spread = units[3];
  }
  if (color) {
    shadowValue.color = color;
  }
  return shadowValue;
};

export const parseCssVar = (node: FunctionNode): undefined | VarValue => {
  const [name, _comma, ...fallback] = node.children;