GraphQL wrapper for `fetch` (based on `TypedDocumentNode`)

fetch-graphql.ts

async function fetchGraphQL<TResult, TVariables>(
    operation: TypedDocumentNode<TResult, TVariables>,
    ...[variables]: TVariables extends Record<string, never> ? [] : [TVariables]
  ): Promise<TResult> {
    const response = await fetch("http://MY-SERVER/graphql", {
      headers: {
        'Content-Type': 'application/json',
         Accept: 'application/json',
      },
      method: 'POST',
      body: JSON.stringify({
        query: typeof operation === 'string' ? operation : print(operation),
        variables,
      }),
    });

    if (!response.ok) {
      throw new Error(`Invalid GraphQL status code: ${response.status}`);
    }

    const jsonData = (await response.json()) as ExecutionResult<TResult>;

    if (jsonData.errors && jsonData.errors.length > 0) {
      throw new Error(
        `Failed to execute GraphQL operation: ${jsonData.errors
          .map(e => e.message)
          .join('\n')}`
      );
    }

    return jsonData.data!;       
}