test: add tests for user-member linking and fuzzy search (#168)

test/accounts/user_member_linking_email_test.exs

@@ -0,0 +1,169 @@
+defmodule Mv.Accounts.UserMemberLinkingEmailTest do
+  @moduledoc """
+  Tests email validation during user-member linking.
+  Implements rules from docs/email-sync.md.
+  Tests for Issue #168, specifically Problem #4: Email validation bug.
+  """
+
+  use Mv.DataCase, async: false
+
+  alias Mv.Accounts
+  alias Mv.Membership
+
+  describe "link with same email" do
+    test "succeeds when user.email == member.email" do
+      # Create member with specific email
+      {:ok, member} =
+        Membership.create_member(%{
+          first_name: "Alice",
+          last_name: "Johnson",
+          email: "alice@example.com"
+        })
+
+      # Create user with same email and link to member
+      result =
+        Accounts.create_user(%{
+          email: "alice@example.com",
+          member: %{id: member.id}
+        })
+
+      # Should succeed without errors
+      assert {:ok, user} = result
+      assert to_string(user.email) == "alice@example.com"
+
+      # Reload to verify link
+      user = Ash.load!(user, [:member], domain: Mv.Accounts)
+      assert user.member.id == member.id
+      assert user.member.email == "alice@example.com"
+    end
+
+    test "no validation error triggered when updating linked pair with same email" do
+      # Create member
+      {:ok, member} =
+        Membership.create_member(%{
+          first_name: "Bob",
+          last_name: "Smith",
+          email: "bob@example.com"
+        })
+
+      # Create user and link
+      {:ok, user} =
+        Accounts.create_user(%{
+          email: "bob@example.com",
+          member: %{id: member.id}
+        })
+
+      # Update user (should not trigger email validation error)
+      result = Accounts.update_user(user, %{email: "bob@example.com"})
+
+      assert {:ok, updated_user} = result
+      assert to_string(updated_user.email) == "bob@example.com"
+    end
+  end
+
+  describe "link with different emails" do
+    test "fails if member.email is used by a DIFFERENT linked user" do
+      # Create first user and link to a different member
+      {:ok, other_member} =
+        Membership.create_member(%{
+          first_name: "Other",
+          last_name: "Member",
+          email: "other@example.com"
+        })
+
+      {:ok, _user1} =
+        Accounts.create_user(%{
+          email: "user1@example.com",
+          member: %{id: other_member.id}
+        })
+
+      # Reload to ensure email sync happened
+      _other_member = Ash.reload!(other_member)
+
+      # Create a NEW member with different email
+      {:ok, member} =
+        Membership.create_member(%{
+          first_name: "Charlie",
+          last_name: "Brown",
+          email: "charlie@example.com"
+        })
+
+      # Try to create user2 with email that matches the linked other_member
+      result =
+        Accounts.create_user(%{
+          email: "user1@example.com",
+          member: %{id: member.id}
+        })
+
+      # Should fail because user1@example.com is already used by other_member (which is linked to user1)
+      assert {:error, _error} = result
+    end
+
+    test "succeeds for unique emails" do
+      # Create member
+      {:ok, member} =
+        Membership.create_member(%{
+          first_name: "David",
+          last_name: "Wilson",
+          email: "david@example.com"
+        })
+
+      # Create user with different but unique email
+      result =
+        Accounts.create_user(%{
+          email: "user@example.com",
+          member: %{id: member.id}
+        })
+
+      # Should succeed
+      assert {:ok, user} = result
+
+      # Email sync should update member's email to match user's
+      user = Ash.load!(user, [:member], domain: Mv.Accounts)
+      assert user.member.email == "user@example.com"
+    end
+  end
+
+  describe "edge cases" do
+    test "unlinking and relinking with same email works (Problem #4)" do
+      # This is the exact scenario from Problem #4:
+      # 1. Link user and member (both have same email)
+      # 2. Unlink them (member keeps the email)
+      # 3. Try to relink (validation should NOT fail)
+
+      # Create member
+      {:ok, member} =
+        Membership.create_member(%{
+          first_name: "Emma",
+          last_name: "Davis",
+          email: "emma@example.com"
+        })
+
+      # Create user and link
+      {:ok, user} =
+        Accounts.create_user(%{
+          email: "emma@example.com",
+          member: %{id: member.id}
+        })
+
+      # Verify they are linked
+      user = Ash.load!(user, [:member], domain: Mv.Accounts)
+      assert user.member.id == member.id
+      assert user.member.email == "emma@example.com"
+
+      # Unlink
+      {:ok, unlinked_user} = Accounts.update_user(user, %{member: nil})
+      assert is_nil(unlinked_user.member_id)
+
+      # Member still has the email after unlink
+      member = Ash.reload!(member)
+      assert member.email == "emma@example.com"
+
+      # Relink (should work - this is Problem #4)
+      result = Accounts.update_user(unlinked_user, %{member: %{id: member.id}})
+
+      assert {:ok, relinked_user} = result
+      assert relinked_user.member_id == member.id
+    end
+  end
+end