Function mergeShapes

packages/core/sdk/src/shape-inference.ts:133–152

(left: InferredShape, right: InferredShape)

 * `anyOf`, degrading to unknown past `MAX_ANYOF` branches.
 */
export const mergeShapes = (left: InferredShape, right: InferredShape): InferredShape => {
  if (isUnknown(left) || isUnknown(right)) return UNKNOWN;

  if (left.anyOf !== undefined || right.anyOf !== undefined) {
    const branches = [...(left.anyOf ?? [left]), ...(right.anyOf ?? [right])];
    return branches.reduce((merged, branch) => addUnionBranch(merged, branch), {
      anyOf: [],
    } as InferredShape);
  }

  if (left.type !== right.type) return addUnionBranch({ anyOf: [left] }, right);

  if (left.type === "object") return mergeObjectShapes(left, right);
  if (left.type === "array") {
    if (left.items === undefined) return right;
    if (right.items === undefined) return left;
    return { type: "array", items: mergeShapes(left.items, right.items) };
  }
  return left;
};

const addUnionBranch = (union: InferredShape, branch: InferredShape): InferredShape => {
  if (isUnknown(union) || isUnknown(branch)) return UNKNOWN;