diff --git a/emoji.go b/emoji.go
index 9216921..58f5844 100644
--- a/emoji.go
+++ b/emoji.go
@@ -113,8 +113,6 @@ func (s *EmojiService) Delete(ctx context.Context, subreddit string, emoji strin
 	return s.client.Do(ctx, req, nil)
 }
 
-//todo: fav subreddits
-
 // SetSize sets the custom emoji size in the subreddit.
 // Both height and width must be between 1 and 40 (inclusive).
 func (s *EmojiService) SetSize(ctx context.Context, subreddit string, height, width int) (*Response, error) {
diff --git a/errors.go b/errors.go
index 744a762..b1acca4 100644
--- a/errors.go
+++ b/errors.go
@@ -6,7 +6,7 @@ import (
 	"net/http"
 )
 
-// APIError is an error coming from Reddit
+// APIError is an error coming from Reddit.
 type APIError struct {
 	Label  string
 	Reason string
@@ -19,17 +19,13 @@ func (e *APIError) Error() string {
 
 // UnmarshalJSON implements the json.Unmarshaler interface.
 func (e *APIError) UnmarshalJSON(data []byte) error {
-	var info []string
+	var info [3]string
 
 	err := json.Unmarshal(data, &info)
 	if err != nil {
 		return err
 	}
 
-	if len(info) != 3 {
-		return fmt.Errorf("got unexpected Reddit error: %v", info)
-	}
-
 	e.Label = info[0]
 	e.Reason = info[1]
 	e.Field = info[2]
@@ -37,9 +33,9 @@ func (e *APIError) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
-// JSONErrorResponse is an error response that sometimes gets returned with a 200 code
+// JSONErrorResponse is an error response that sometimes gets returned with a 200 code.
 type JSONErrorResponse struct {
-	// HTTP response that caused this error
+	// HTTP response that caused this error.
 	Response *http.Response `json:"-"`
 
 	JSON *struct {
@@ -78,3 +74,5 @@ func (r *ErrorResponse) Error() string {
 		r.Response.Request.Method, r.Response.Request.URL, r.Response.StatusCode, r.Message,
 	)
 }
+
+// todo: rate limit errors
diff --git a/reddit_test.go b/reddit_test.go
index 8ab41ff..3c2f200 100644
--- a/reddit_test.go
+++ b/reddit_test.go
@@ -111,3 +111,82 @@ func TestNewClient_Error(t *testing.T) {
 	_, err := NewClient(nil, errorOpt)
 	require.EqualError(t, err, "foo")
 }
+
+func TestClient_OnRequestComplemented(t *testing.T) {
+	setup()
+	defer teardown()
+
+	var i int
+	cb := func(*http.Request, *http.Response) {
+		i++
+	}
+	client.OnRequestCompleted(cb)
+
+	mux.HandleFunc("/api/v1/test", func(w http.ResponseWriter, r *http.Request) {
+		require.Equal(t, http.MethodGet, r.Method)
+	})
+
+	req, err := client.NewRequest(http.MethodGet, "api/v1/test", nil)
+	require.NoError(t, err)
+
+	_, _ = client.Do(ctx, req, nil)
+	require.Equal(t, 1, i)
+
+	_, _ = client.Do(ctx, req, nil)
+	_, _ = client.Do(ctx, req, nil)
+	_, _ = client.Do(ctx, req, nil)
+	_, _ = client.Do(ctx, req, nil)
+	require.Equal(t, 5, i)
+
+	_, _ = client.Do(ctx, req, nil)
+	require.Equal(t, 6, i)
+}
+
+func TestClient_JSONErrorResponse(t *testing.T) {
+	setup()
+	defer teardown()
+
+	mux.HandleFunc("/api/v1/test", func(w http.ResponseWriter, r *http.Request) {
+		require.Equal(t, http.MethodGet, r.Method)
+		fmt.Fprint(w, `{
+			"json": {
+				"errors": [
+					[
+						"TEST_ERROR",
+						"this is a test error",
+						"test field"
+					]
+				]
+			}
+		}`)
+	})
+
+	req, err := client.NewRequest(http.MethodGet, "api/v1/test", nil)
+	require.NoError(t, err)
+
+	resp, err := client.Do(ctx, req, nil)
+	require.IsType(t, &JSONErrorResponse{}, err)
+	require.EqualError(t, err, fmt.Sprintf(`GET %s/api/v1/test: 200 field "test field" caused TEST_ERROR: this is a test error`, server.URL))
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+}
+
+func TestClient_ErrorResponse(t *testing.T) {
+	setup()
+	defer teardown()
+
+	mux.HandleFunc("/api/v1/test", func(w http.ResponseWriter, r *http.Request) {
+		require.Equal(t, http.MethodGet, r.Method)
+		w.WriteHeader(http.StatusForbidden)
+		fmt.Fprint(w, `{
+			"message": "error message"
+		}`)
+	})
+
+	req, err := client.NewRequest(http.MethodGet, "api/v1/test", nil)
+	require.NoError(t, err)
+
+	resp, err := client.Do(ctx, req, nil)
+	require.IsType(t, &ErrorResponse{}, err)
+	require.EqualError(t, err, fmt.Sprintf(`GET %s/api/v1/test: 403 error message`, server.URL))
+	require.Equal(t, http.StatusForbidden, resp.StatusCode)
+}
diff --git a/things.go b/things.go
index a40bf79..9a07ba3 100644
--- a/things.go
+++ b/things.go
@@ -425,17 +425,13 @@ type PostAndComments struct {
 // The 1st one contains the single post in its children array
 // The 2nd one contains the comments to the post
 func (pc *PostAndComments) UnmarshalJSON(data []byte) error {
-	var l []rootListing
+	var l [2]rootListing
 
 	err := json.Unmarshal(data, &l)
 	if err != nil {
 		return err
 	}
 
-	if len(l) < 2 {
-		return errors.New("unexpected json response when getting post")
-	}
-
 	post := l[0].getPosts().Posts[0]
 	comments := l[1].getComments().Comments
 	moreComments := l[1].getMoreComments()