// first, create an instance of the fake server for the client you wish to test.

// the type name of the server will be similar to the corresponding client, with

// the suffix "Server" instead of "Client".

fakeVirtualMachinesServer := fake.VirtualMachinesServer{

// next, provide implementations for the APIs you wish to fake.

// this fake corresponds to the VirtualMachinesClient.Get() API.

Get: func(ctx context.Context, resourceGroupName, vmName string, options *armcompute.VirtualMachinesClientGetOptions) (resp azfake.Responder[armcompute.VirtualMachinesClientGetResponse], errResp azfake.ErrorResponder) {

// the values of ctx, resourceGroupName, vmName, and options come from the API call.

// the named return values resp and errResp are used to construct the response

// and are meant to be mutually exclusive. if both responses have been constructed,

// the error response is selected.

// construct the response type, populating fields as required

vmResp := armcompute.VirtualMachinesClientGetResponse{}

vmResp.ID = to.Ptr("/fake/resource/id")

// use resp to set the desired response

resp.SetResponse(http.StatusOK, vmResp, nil)

// to simulate the failure case, use errResp

// errResp.SetResponseError(http.StatusBadRequest, "ThisIsASimulatedError")

return

},

}

// now create the corresponding client, connecting the fake server via the client options

client, err := armcompute.NewVirtualMachinesClient("subscriptionID", &azfake.TokenCredential{}, &arm.ClientOptions{

ClientOptions: azcore.ClientOptions{

Transport: fake.NewVirtualMachinesServerTransport(&fakeVirtualMachinesServer),

},

})

if err != nil {

log.Fatal(err)

}

// call the API. the provided values will be passed to the fake's implementation.

// the response or error values returned by the API call are from the fake.

resp, err := client.Get(context.TODO(), "fakeResourceGroup", "fakeVM", nil)

if err != nil {

log.Fatal(err)

}

fmt.Println(*resp.ID)

// APIs that haven't been faked will return an error

_, err = client.BeginDeallocate(context.TODO(), "fakeResourceGroup", "fakeVM", nil)

fmt.Println(err.Error())

// Output:

// /fake/resource/id

// fake for method BeginDeallocate not implemented