added gzip decompression of response body

reddit/reddit.go

@@ -2,6 +2,7 @@ package reddit
 
 import (
 	"bytes"
+	"compress/gzip"
 	"context"
 	"encoding/json"
 	"fmt"
@@ -372,15 +373,30 @@ func (c *Client) Do(ctx context.Context, req *http.Request, v interface{}) (*Res
 	c.rateMu.Unlock()
 
 	err = CheckResponse(resp)
-	if err != nil {
+	if err != nil || v == nil {
 		return response, err
 	}
 
-	if v != nil {
-		if w, ok := v.(io.Writer); ok {
-			_, err = io.Copy(w, response.Body)
+	w, ok := v.(io.Writer)
+	if ok {
+		_, err = io.Copy(w, response.Body)
+		if err != nil {
+			return response, err
+		}
+	} else {
+		if response.Header.Get("Content-Encoding") == "gzip" {
+			gzipReader, err := gzip.NewReader(resp.Body)
 			if err != nil {
-				return response, err
+				return response, fmt.Errorf("Error creating gzip reader: %s", err)
+			}
+			defer gzipReader.Close()
+			b, err := io.ReadAll(gzipReader)
+			if err != nil {
+				return response, fmt.Errorf("Error decoding gzip json: %s", err)
+			}
+			err = json.Unmarshal(b, v)
+			if err != nil {
+				return response, fmt.Errorf("Error unmarshalling json: %s", err)
 			}
 		} else {
 			err = json.NewDecoder(response.Body).Decode(v)
@@ -388,10 +404,10 @@ func (c *Client) Do(ctx context.Context, req *http.Request, v interface{}) (*Res
 				return response, err
 			}
 		}
+	}
 
-		if anchor, ok := v.(anchor); ok {
-			response.populateAnchors(anchor)
-		}
+	if anchor, ok := v.(anchor); ok {
+		response.populateAnchors(anchor)
 	}
 
 	return response, nil