X_TEST_OPENAPI_EXPECTED
Means
a matcher expected an OpenAPI document and got something else
Typical cause
toMatchOpenApi answered pass:false for a receiver that is not an OpenAPI document, so .not.toMatchOpenApi passed on anything at all
Fix
expect(await app.openapi()).toMatchOpenApi(committed) — the receiver is the generated document: an object with operations: [{ operationId, required? }]