RequestSerializationError

The Cause

The request could not be built from what the API description and your hooks supplied. Something a request needs is missing or is not a value HTTP can carry:

• a path parameter with no value — GET /launches/{id} with nothing for id;
• a path or query parameter that is an object or an array where the serialization style expects a scalar;
• a header whose value is not a string;
• a body that cannot be turned into text.

This is not a defect: it is the API description not saying enough for one Transaction to be executed as described.

What to do

The message names the value, and nothing else — the Transaction it belongs to is already printed above it wherever this appears:

↷ GET /launches/{id} -> 200 (application/json)
    Missing value for path parameter "id".
    Give it a value with an example in the API description, or set it from a hook.

Two ways to supply the value:

• In the description. Add an example to the parameter, which the sampler reflects into the generated request.

• In a hook. Set it where a real value comes from — usually a seeding call that creates the resource first:

  import { beforeEach } from '@thymian/hooks';
  
  export const seedLaunch = beforeEach('GET /launches/{id} -> 200 (application/json)', async (request, ctx, utils) => {
    const created = await utils.request('POST /launches (application/json) -> 201 (application/json)', { body: { name: 'Artemis' } });
  
    if (created.statusCode !== 201) {
      utils.skip('the launch to read could not be created');
    }
  
    request.pathParameters['id'] = created.body.id;
  });

In thymian sampler check a Transaction whose request cannot be built is skipped, not failed: nothing was learned about the API, and the run continues through every other Transaction.