Do not attempt to standardise response bodies when we don't need to (t…

…ailscale#20)

Related to https://github.com/davidsbond/terraform-provider-tailscale/issues/113

This commit modifies the request making code to not attempt to standardise
response bodies if we are not attempting to parse the response. For example, the
tailnet key delete API response has an empty body, which would cause errors when
calling hujson.Standardize.

Signed-off-by: David Bond <davidsbond93@gmail.com>

tailscale/client.go

@@ -123,11 +123,24 @@ func (c *Client) performRequest(req *http.Request, out interface{}) error {
 	if err != nil {
 		return err
 	}
-	if !json.Valid(body) {
-		body, err = hujson.Standardize(body)
-		if err != nil {
-			return err
+
+	if res.StatusCode >= http.StatusOK && res.StatusCode < http.StatusMultipleChoices {
+		// If we don't care about the response body, leave. This check is required as some
+		// API responses have empty bodies, so we don't want to try and standardize them for
+		// parsing.
+		if out == nil {
+			return nil
+		}
+
+		// If we've got hujson back, convert it to JSON, so we can natively parse it.
+		if !json.Valid(body) {
+			body, err = hujson.Standardize(body)
+			if err != nil {
+				return err
+			}
 		}
+
+		return json.Unmarshal(body, out)
 	}
 
 	if res.StatusCode != http.StatusOK && res.StatusCode != http.StatusCreated {
@@ -140,10 +153,6 @@ func (c *Client) performRequest(req *http.Request, out interface{}) error {
 		return apiErr
 	}
 
-	if out != nil {
-		return json.Unmarshal(body, out)
-	}
-
 	return nil
 }
 

tailscale/tailscale_test.go

@@ -67,5 +67,7 @@ func (t *TestServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	assert.NoError(t.t, err)
 
 	w.WriteHeader(t.ResponseCode)
-	assert.NoError(t.t, json.NewEncoder(w).Encode(t.ResponseBody))
+	if t.ResponseBody != nil {
+		assert.NoError(t.t, json.NewEncoder(w).Encode(t.ResponseBody))
+	}
 }