testing-handlers

Test Setup

Most handler tests require the same boilerplate code and setup steps.

Create the necessary models in the DB. For example:

move := testdatagen.MakeDefaultMove(suite.DB())
order := move.Orders

Set up the Body of the HTTP request if creating or updating a model:

body := &ghcmessages.UpdateOrderPayload{
    Sac: handlers.FmtString("987654321"),
}

Define the request:

request := httptest.NewRequest("PATCH", "/orders/{orderID}", nil)

Set up the params:

params := orderop.UpdateOrderParams{
    HTTPRequest: request,
    OrderID:     strfmt.UUID(order.ID.String()),
    IfMatch:     etag.GenerateEtag(order.UpdatedAt),
    Body:        body,
}

Set up the context:

context := handlers.NewHandlerConfig(suite.DB(), suite.TestLogger())

Set up the handler:

handler := UpdateOrderHandler{
    context,
    orderservice.NewOrderUpdater(suite.DB()),
}

Validate the Body. This runs the Swagger validation against the generated params before passing to the handler, which is what happens when the real endpoint is hit.
```
suite.NoError(params.Body.Validate(strfmt.Default))
```
Finally make the request:
```
response := handler.Handle(params)
```

To test the response, make sure to test all the fields that you expect to be present. For example:

response := handler.Handle(params)
suite.IsNotErrResponse(response)
orderOK := response.(*orderop.GetOrderOK)
ordersPayload := orderOK.Payload

suite.Assertions.IsType(&orderop.GetOrderOK{}, response)
suite.Equal(order.ID.String(), ordersPayload.ID.String())
suite.Equal(move.Locator, ordersPayload.MoveCode)
suite.NotNil(order.NewDutyStation)
suite.NotZero(order.OriginDutyStation)
suite.NotZero(ordersPayload.DateIssued)

Note that the expected order of arguments to suite.Equal is (expected, actual). The payload attributes should always be on the right. This makes it easier to troubleshoot. Whenever a value is known, we want to prefer checking explicitly for the value using suite.Equal or suite.EqualValues. Read the Testing Best Practices for more guidance.

Inspecting the response

Because we use Swagger to generate API code, each handler has its own response type for each defined HTTP status. For example, when the status is 200, the UpdateOrder handler has a response type of orderop.UpdateOrderOK{}. To get the payload of the response, you have to do something like this:

payload := response.(*orderop.UpdateOrderOK).Payload

Then you can fetch the various attributes, such as payload.MoveCode.

If you're used to web frameworks like Rails, you might prefer to inspect the payload as JSON for debugging. Here's how to parse the response as JSON:

payload := response.(*orderop.UpdateOrderOK).Payload
jsonPayload, errJSONMarshall := json.Marshal(payload)
if errJSONMarshall != nil {
  fmt.Println("failed to parse payload as JSON")
}
fmt.Println(string(jsonPayload))

Test Setup​

Inspecting the response​

Test Setup

Inspecting the response