CAP: Mocking requests to third party Services in tests

[muellinho]

Hello experts,

in my CAP project I'm sending OData Requests to an external API to fetch some data and work on that data.

I wanted to write a Test to make sure, that the operations I do on the data that the external API returns, return the result that I expect.

I'm running my tests via the following command

npx jest --collectCoverage

And in my test start a CDS Server using the following statements:

const project = __dirname+'/..'; // The projects root folder
const cds = require('@sap/cds/lib');
cds.test(project);

as recommended in the documentation capire - Testing (cloud.sap).

When my module which makes a request to the external API is called, and tries to cds.connect.to('service-name') the Service that I'm using, I'm receiving the error message:

"Error: No credentials configured for <service-name>".

I guess that this is actually fine though, since in my CDS config I only provided the credentials for the production profile, to enable local testing through sqlite / mockdata provided via corresponding csv-files:

...
"service-name": {
    "kind": "odata-v2",
    "model": "path/to/srv/model",
    "[production]":{
        "credentials": {
            "destination": "myDestination"
        }
    }
}

Now my question is:

Can I make 'cds.test(...)' run the CAP server using my mockdata from the directory "srv/external/data" the same way as 'cds watch' does or is there another way to mock external APIs when executing tests?

Unfortunately I didn't find anything regarding this topic.

Thanks for any help / hints,

Regards

Jan

[muellinho · Accepted solution]

Hi,

I found the following solution for my problem, so I'm sharing it before closing the question:

CDS.test() can take more than 1 argument. The additional arguments are then passed to the cds serve command under the hood, so executing

cds.test(project,'--with-mocks');

instead of

cds.test(project);

started the CAP server in my Jest tests with the mockdata of my CSV files and then also didn't try to connect to the remote services.

Best regards

Jan