move a bunch of the logic from generated into client

graphql/client.go

@@ -0,0 +1,67 @@
+package graphql
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"strings"
+
+	"github.com/vektah/gqlparser/gqlerror"
+)
+
+type Client struct {
+	endpoint   string
+	method     string
+	httpClient *http.Client
+}
+
+func NewClient(endpoint string, httpClient *http.Client) *Client {
+	if httpClient == nil {
+		httpClient = http.DefaultClient
+	}
+	return &Client{endpoint, http.MethodPost, httpClient}
+}
+
+func (client *Client) MakeRequest(ctx context.Context, query string, retval interface{}) error {
+	req, err := http.NewRequest(
+		client.method,
+		client.endpoint,
+		strings.NewReader(query))
+	if err != nil {
+		return err
+	}
+
+	req = req.WithContext(ctx)
+	resp, err := client.httpClient.Do(req)
+	if err != nil {
+		return err
+	}
+	defer resp.Body.Close()
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return err
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("returned error %v: %v", resp.Status, string(body))
+	}
+
+	var dataAndErrors struct {
+		Data   json.RawMessage `json:"data"`
+		Errors gqlerror.List   `json:"errors"`
+	}
+
+	err = json.Unmarshal(body, &dataAndErrors)
+	if err != nil {
+		return err
+	}
+
+	if len(dataAndErrors.Errors) > 0 {
+		return dataAndErrors.Errors
+	}
+
+	return json.Unmarshal(dataAndErrors.Data, &retval)
+}