export interface ErrorResponse {
[key: string]: unknown;
content: { type: 'text'; text: string }[];
structuredContent: {
ok: false;
error: { code: string; message: string };
result?: unknown;
};
isError: true;
}
function extractFromError(error: unknown): string | undefined {
return error instanceof Error ? error.message : undefined;
}
function extractFromString(error: unknown): string | undefined {
return typeof error === 'string' && error.length > 0 ? error : undefined;
}
function hasMessageProp(error: unknown): error is { message?: unknown } {
return Boolean(error && typeof error === 'object' && 'message' in error);
}
function extractFromMessageProp(error: unknown): string | undefined {
if (!hasMessageProp(error)) return undefined;
const msg = error.message;
return typeof msg === 'string' && msg.length > 0 ? msg : undefined;
}
export function getErrorMessage(error: unknown): string {
return (
extractFromError(error) ??
extractFromString(error) ??
extractFromMessageProp(error) ??
'Unknown error'
);
}
export function createErrorResponse(
code: string,
message: string,
result?: unknown
): ErrorResponse {
const structured: ErrorResponse['structuredContent'] = {
ok: false,
error: { code, message },
...(result === undefined ? {} : { result }),
};
return {
content: [{ type: 'text' as const, text: JSON.stringify(structured) }],
structuredContent: structured,
isError: true as const,
};
}
