Make client return error on JSON decoding error

If the response is not valid JSON, the request simply returns an
empty body. If the user is expecting the result to be JSON and its
not, we should signal that an error has occured.

This patch also includes fixes to tests that fail due to the
error that bubbles up.

Author: pratikmallya

openstack/compute/v2/extensions/secgroups/fixtures.go

@@ -242,6 +242,7 @@ func mockAddServerToGroupResponse(t *testing.T, serverID string) {
 
 		w.Header().Add("Content-Type", "application/json")
 		w.WriteHeader(http.StatusAccepted)
+		fmt.Fprintf(w, `{}`)
 	})
 }
 
@@ -261,5 +262,6 @@ func mockRemoveServerFromGroupResponse(t *testing.T, serverID string) {
 
 		w.Header().Add("Content-Type", "application/json")
 		w.WriteHeader(http.StatusAccepted)
+		fmt.Fprintf(w, `{}`)
 	})
 }

openstack/compute/v2/servers/requests.go

@@ -754,9 +754,7 @@ func Metadatum(client *gophercloud.ServiceClient, id, key string) GetMetadatumRe
 // DeleteMetadatum will delete the key-value pair with the given key for the given server ID.
 func DeleteMetadatum(client *gophercloud.ServiceClient, id, key string) DeleteMetadatumResult {
 	var res DeleteMetadatumResult
-	_, res.Err = client.Delete(metadatumURL(client, id, key), &gophercloud.RequestOpts{
-		JSONResponse: &res.Body,
-	})
+	_, res.Err = client.Delete(metadatumURL(client, id, key), nil)
 	return res
 }
 

openstack/networking/v2/extensions/fwaas/firewalls/requests_test.go

@@ -212,9 +212,9 @@ func TestUpdate(t *testing.T) {
         "name": "fw",
         "admin_state_up": false,
         "tenant_id": "b4eedccc6fb74fa8a7ad6b08382b852b",
-        "firewall_policy_id": "19ab8c87-4a32-4e6a-a74e-b77fffb89a0c"
+        "firewall_policy_id": "19ab8c87-4a32-4e6a-a74e-b77fffb89a0c",
         "id": "ea5b5315-64f6-4ea3-8e58-981cc37c6576",
-        "description": "OpenStack firewall",
+        "description": "OpenStack firewall"
     }
 }
     `)

openstack/networking/v2/extensions/lbaas/pools/requests_test.go

@@ -296,6 +296,7 @@ func TestAssociateHealthMonitor(t *testing.T) {
 
 		w.Header().Add("Content-Type", "application/json")
 		w.WriteHeader(http.StatusCreated)
+		fmt.Fprintf(w, `{}`)
 	})
 
 	_, err := AssociateMonitor(fake.ServiceClient(), "332abe93-f488-41ba-870b-2ac66be7f853", "b624decf-d5d3-4c66-9a3d-f047e7786181").Extract()

openstack/networking/v2/networks/requests_test.go

@@ -204,6 +204,7 @@ func TestCreateWithOptionalFields(t *testing.T) {
 		`)
 
 		w.WriteHeader(http.StatusCreated)
+		fmt.Fprintf(w, `{}`)
 	})
 
 	iTrue := true

provider_client.go

@@ -227,7 +227,9 @@ func (client *ProviderClient) Request(method, url string, options RequestOpts) (
 	// Parse the response body as JSON, if requested to do so.
 	if options.JSONResponse != nil {
 		defer resp.Body.Close()
-		json.NewDecoder(resp.Body).Decode(options.JSONResponse)
+		if err := json.NewDecoder(resp.Body).Decode(options.JSONResponse); err != nil {
+			return nil, err
+		}
 	}
 
 	return resp, nil

rackspace/lb/v1/sessions/fixtures.go

@@ -46,6 +46,7 @@ func mockEnableResponse(t *testing.T, lbID int) {
     `)
 
 		w.WriteHeader(http.StatusAccepted)
+		fmt.Fprintf(w, `{}`)
 	})
 }
 

rackspace/lb/v1/ssl/fixtures.go

@@ -63,6 +63,7 @@ func mockUpdateResponse(t *testing.T, lbID int) {
     `)
 
 		w.WriteHeader(http.StatusOK)
+		fmt.Fprintf(w, `{}`)
 	})
 }
 

rackspace/lb/v1/throttle/fixtures.go

@@ -49,6 +49,7 @@ func mockCreateResponse(t *testing.T, lbID int) {
     `)
 
 		w.WriteHeader(http.StatusAccepted)
+		fmt.Fprintf(w, `{}`)
 	})
 }
 

rackspace/networking/v2/networks/delegate_test.go

@@ -203,8 +203,17 @@ func TestCreateWithOptionalFields(t *testing.T) {
 	}
 }
 		`)
-
 		w.WriteHeader(http.StatusCreated)
+		fmt.Fprintf(w, `
+{
+	"network": {
+			"name": "sample_network",
+			"admin_state_up": true,
+			"shared": true,
+			"tenant_id": "12345"
+	}
+}
+		`)
 	})
 
 	iTrue := true