refac: hardening pass with multiple overhauls

test/invite_email_validation_http_test.go

@@ -0,0 +1,59 @@
+package test
+
+import (
+	"encoding/json"
+	"net/http"
+	"os"
+	"testing"
+)
+
+type inviteEmailCase struct {
+	Email string `json:"email"`
+	Valid bool   `json:"valid"`
+}
+
+func loadInviteEmailCases(t *testing.T) []inviteEmailCase {
+	t.Helper()
+	raw, err := os.ReadFile("testdata/invite_emails.json")
+	if err != nil {
+		t.Fatalf("read fixture: %v", err)
+	}
+	var cases []inviteEmailCase
+	if err := json.Unmarshal(raw, &cases); err != nil {
+		t.Fatalf("decode fixture: %v", err)
+	}
+	return cases
+}
+
+func TestInviteEmailValidationHttp(t *testing.T) {
+	t.Run("The same address gets the same verdict on both sides", func(t *testing.T) {
+		for _, tc := range loadInviteEmailCases(t) {
+			t.Run("["+tc.Email+"]", func(t *testing.T) {
+				f := newInviteFixture(t, 100)
+				body, _ := json.Marshal(map[string]string{"email": tc.Email})
+
+				rec := f.post(t, string(body))
+
+				if tc.Valid && rec.Code != http.StatusCreated {
+					t.Errorf("expected 201, got %d: %s", rec.Code, rec.Body.String())
+				}
+				if !tc.Valid && rec.Code != http.StatusBadRequest {
+					t.Errorf("expected 400, got %d: %s", rec.Code, rec.Body.String())
+				}
+			})
+		}
+	})
+
+	t.Run("A rejected address stores nothing and sends nothing", func(t *testing.T) {
+		f := newInviteFixture(t, 100)
+
+		rec := f.post(t, `{"email": "user@localhost"}`)
+
+		if rec.Code != http.StatusBadRequest {
+			t.Errorf("expected 400, got %d", rec.Code)
+		}
+		if len(f.invites.invites) != 0 || len(f.mail.SentEmails) != 0 {
+			t.Errorf("nothing may be stored or sent, got %d invites and %d emails", len(f.invites.invites), len(f.mail.SentEmails))
+		}
+	})
+}