write tests

internal/api/accounts.go

@@ -195,7 +195,7 @@ func (a *api) upsertAccountsHandler(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 
-		resp, err := a.httpClient.Do(req)
+		resp, _ := a.httpClient.Do(req)
 		resp.Body.Close()
 	}(apns)
 

internal/domain/subreddit.go

@@ -2,6 +2,7 @@ package domain
 
 import (
 	"context"
+	"errors"
 	"regexp"
 	"strings"
 
@@ -21,9 +22,21 @@ func (sr *Subreddit) NormalizedName() string {
 	return strings.ToLower(sr.Name)
 }
 
+func validPrefix(value interface{}) error {
+	s, _ := value.(string)
+	if len(s) < 2 {
+		return nil
+	}
+	if s[1] != '_' || s[0] != 'u' {
+		return nil
+	}
+
+	return errors.New("invalid subreddit format")
+}
+
 func (sr *Subreddit) Validate() error {
 	return validation.ValidateStruct(sr,
-		validation.Field(&sr.Name, validation.Required, validation.Length(3, 32), validation.Match(regexp.MustCompile(`^(?!u_)[a-zA-Z0-9]\w{1,19}$`))),
+		validation.Field(&sr.Name, validation.Required, validation.Length(3, 32), validation.By(validPrefix), validation.Match(regexp.MustCompile(`^[a-zA-Z0-9]\w{1,19}$`))),
 		validation.Field(&sr.SubredditID, validation.Required, validation.Length(4, 9)),
 	)
 }

internal/domain/subreddit_test.go

@@ -0,0 +1,34 @@
+package domain
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestValidate(t *testing.T) {
+	tests := map[string]struct {
+		subreddit Subreddit
+		err       error
+	}{
+		"invalid subreddit prefix":        {Subreddit{Name: "u_iamthatis"}, errors.New("invalid subreddit format")},
+		"valid subreddit":                 {Subreddit{Name: "pics", SubredditID: "abcd"}, nil},
+		"valid subreddit starting with u": {Subreddit{Name: "urcool", SubredditID: "abcd"}, nil},
+		"valid subreddit with _":          {Subreddit{Name: "p_i_x_a_r", SubredditID: "abcd"}, nil},
+	}
+
+	for scenario, tc := range tests {
+		t.Run(scenario, func(t *testing.T) {
+			err := tc.subreddit.Validate()
+
+			if tc.err == nil {
+				require.NoError(t, err)
+				return
+			}
+
+			assert.Error(t, err)
+		})
+	}
+}