From 88bed75ac9254b761b1b17d8b3ebcc42761f8caf Mon Sep 17 00:00:00 2001
From: Moritz <moritz.m@local-it.org>
Date: Thu, 20 Nov 2025 15:51:44 +0100
Subject: [PATCH] test: add tests for user-member linking and fuzzy search
 (#168)

---
 .../user_member_linking_email_test.exs        | 169 +++++++++++++
 test/accounts/user_member_linking_test.exs    | 130 ++++++++++
 .../member_available_for_linking_test.exs     | 222 ++++++++++++++++++
 .../member_fuzzy_search_linking_test.exs      | 158 +++++++++++++
 4 files changed, 679 insertions(+)
 create mode 100644 test/accounts/user_member_linking_email_test.exs
 create mode 100644 test/accounts/user_member_linking_test.exs
 create mode 100644 test/membership/member_available_for_linking_test.exs
 create mode 100644 test/membership/member_fuzzy_search_linking_test.exs

diff --git a/test/accounts/user_member_linking_email_test.exs b/test/accounts/user_member_linking_email_test.exs
new file mode 100644
index 0000000..5d72ac9
--- /dev/null
+++ b/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: true
+
+  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
diff --git a/test/accounts/user_member_linking_test.exs b/test/accounts/user_member_linking_test.exs
new file mode 100644
index 0000000..1111436
--- /dev/null
+++ b/test/accounts/user_member_linking_test.exs
@@ -0,0 +1,130 @@
+defmodule Mv.Accounts.UserMemberLinkingTest do
+  @moduledoc """
+  Integration tests for User-Member linking functionality.
+
+  Tests the complete workflow of linking and unlinking members to users,
+  including email synchronization and validation rules.
+  """
+  use Mv.DataCase, async: false
+  alias Mv.Accounts
+  alias Mv.Membership
+
+  describe "User-Member Linking with Email Sync" do
+    test "link user to member with different email syncs member email" do
+      # Create user with one email
+      {:ok, user} = Accounts.create_user(%{email: "user@example.com"})
+
+      # Create member with different email
+      {:ok, member} =
+        Membership.create_member(%{
+          first_name: "John",
+          last_name: "Doe",
+          email: "member@example.com"
+        })
+
+      # Link user to member
+      {:ok, updated_user} = Accounts.update_user(user, %{member: %{id: member.id}})
+
+      # Verify link exists
+      user_with_member = Ash.get!(Mv.Accounts.User, updated_user.id, load: [:member])
+      assert user_with_member.member.id == member.id
+
+      # Verify member email was synced to match user email
+      synced_member = Ash.get!(Mv.Membership.Member, member.id)
+      assert synced_member.email == "user@example.com"
+    end
+
+    test "unlink member from user sets member to nil" do
+      # Create and link user and member
+      {:ok, user} = Accounts.create_user(%{email: "user@example.com"})
+
+      {:ok, member} =
+        Membership.create_member(%{
+          first_name: "Jane",
+          last_name: "Smith",
+          email: "jane@example.com"
+        })
+
+      {:ok, linked_user} = Accounts.update_user(user, %{member: %{id: member.id}})
+
+      # Verify link exists
+      user_with_member = Ash.get!(Mv.Accounts.User, linked_user.id, load: [:member])
+      assert user_with_member.member.id == member.id
+
+      # Unlink by setting member to nil
+      {:ok, unlinked_user} = Accounts.update_user(linked_user, %{member: nil})
+
+      # Verify link is removed
+      user_without_member = Ash.get!(Mv.Accounts.User, unlinked_user.id, load: [:member])
+      assert is_nil(user_without_member.member)
+
+      # Verify member still exists independently
+      member_still_exists = Ash.get!(Mv.Membership.Member, member.id)
+      assert member_still_exists.id == member.id
+    end
+
+    test "cannot link member already linked to another user" do
+      # Create first user and link to member
+      {:ok, user1} = Accounts.create_user(%{email: "user1@example.com"})
+
+      {:ok, member} =
+        Membership.create_member(%{
+          first_name: "Bob",
+          last_name: "Wilson",
+          email: "bob@example.com"
+        })
+
+      {:ok, _linked_user1} = Accounts.update_user(user1, %{member: %{id: member.id}})
+
+      # Create second user and try to link to same member
+      {:ok, user2} = Accounts.create_user(%{email: "user2@example.com"})
+
+      # Should fail because member is already linked
+      assert {:error, %Ash.Error.Invalid{}} =
+               Accounts.update_user(user2, %{member: %{id: member.id}})
+    end
+
+    test "cannot change member link directly, must unlink first" do
+      # Create user and link to first member
+      {:ok, user} = Accounts.create_user(%{email: "user@example.com"})
+
+      {:ok, member1} =
+        Membership.create_member(%{
+          first_name: "Alice",
+          last_name: "Johnson",
+          email: "alice@example.com"
+        })
+
+      {:ok, linked_user} = Accounts.update_user(user, %{member: %{id: member1.id}})
+
+      # Create second member
+      {:ok, member2} =
+        Membership.create_member(%{
+          first_name: "Charlie",
+          last_name: "Brown",
+          email: "charlie@example.com"
+        })
+
+      # Try to directly change member link (should fail)
+      assert {:error, %Ash.Error.Invalid{errors: errors}} =
+               Accounts.update_user(linked_user, %{member: %{id: member2.id}})
+
+      # Verify error message mentions "Remove existing member first"
+      error_messages = Enum.map(errors, & &1.message)
+      assert Enum.any?(error_messages, &String.contains?(&1, "Remove existing member first"))
+
+      # Two-step process: first unlink, then link new member
+      {:ok, unlinked_user} = Accounts.update_user(linked_user, %{member: nil})
+
+      # After unlinking, member1 still has the user's email
+      # Change member1's email to avoid conflict when relinking to member2
+      {:ok, _} = Membership.update_member(member1, %{email: "alice_changed@example.com"})
+
+      {:ok, relinked_user} = Accounts.update_user(unlinked_user, %{member: %{id: member2.id}})
+
+      # Verify new link is established
+      user_with_new_member = Ash.get!(Mv.Accounts.User, relinked_user.id, load: [:member])
+      assert user_with_new_member.member.id == member2.id
+    end
+  end
+end
diff --git a/test/membership/member_available_for_linking_test.exs b/test/membership/member_available_for_linking_test.exs
new file mode 100644
index 0000000..602fdfd
--- /dev/null
+++ b/test/membership/member_available_for_linking_test.exs
@@ -0,0 +1,222 @@
+defmodule Mv.Membership.MemberAvailableForLinkingTest do
+  @moduledoc """
+  Tests for the Member.available_for_linking action.
+
+  This action returns members that can be linked to a user account:
+  - Only members without existing user links (user_id == nil)
+  - Limited to 10 results
+  - Special email-match logic: if user_email matches member email, only return that member
+  - Optional search query filtering by name and email
+  """
+  use Mv.DataCase, async: true
+  alias Mv.Membership
+
+  describe "available_for_linking/2" do
+    setup do
+      # Create 5 unlinked members with distinct names
+      {:ok, member1} =
+        Membership.create_member(%{
+          first_name: "Alice",
+          last_name: "Anderson",
+          email: "alice@example.com"
+        })
+
+      {:ok, member2} =
+        Membership.create_member(%{
+          first_name: "Bob",
+          last_name: "Williams",
+          email: "bob@example.com"
+        })
+
+      {:ok, member3} =
+        Membership.create_member(%{
+          first_name: "Charlie",
+          last_name: "Davis",
+          email: "charlie@example.com"
+        })
+
+      {:ok, member4} =
+        Membership.create_member(%{
+          first_name: "Diana",
+          last_name: "Martinez",
+          email: "diana@example.com"
+        })
+
+      {:ok, member5} =
+        Membership.create_member(%{
+          first_name: "Emma",
+          last_name: "Taylor",
+          email: "emma@example.com"
+        })
+
+      unlinked_members = [member1, member2, member3, member4, member5]
+
+      # Create 2 linked members (with users)
+      {:ok, user1} = Mv.Accounts.create_user(%{email: "user1@example.com"})
+
+      {:ok, linked_member1} =
+        Membership.create_member(%{
+          first_name: "Linked",
+          last_name: "Member1",
+          email: "linked1@example.com",
+          user: %{id: user1.id}
+        })
+
+      {:ok, user2} = Mv.Accounts.create_user(%{email: "user2@example.com"})
+
+      {:ok, linked_member2} =
+        Membership.create_member(%{
+          first_name: "Linked",
+          last_name: "Member2",
+          email: "linked2@example.com",
+          user: %{id: user2.id}
+        })
+
+      %{
+        unlinked_members: unlinked_members,
+        linked_members: [linked_member1, linked_member2]
+      }
+    end
+
+    test "returns only unlinked members and limits to 10", %{
+      unlinked_members: unlinked_members,
+      linked_members: _linked_members
+    } do
+      # Call the action without any arguments
+      members =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{})
+        |> Ash.read!()
+
+      # Should return only the 5 unlinked members, not the 2 linked ones
+      assert length(members) == 5
+
+      returned_ids = Enum.map(members, & &1.id) |> MapSet.new()
+      expected_ids = Enum.map(unlinked_members, & &1.id) |> MapSet.new()
+
+      assert MapSet.equal?(returned_ids, expected_ids)
+
+      # Verify none of the returned members have a user_id
+      Enum.each(members, fn member ->
+        member_with_user = Ash.get!(Mv.Membership.Member, member.id, load: [:user])
+        assert is_nil(member_with_user.user)
+      end)
+    end
+
+    test "limits results to 10 members even when more exist" do
+      # Create 15 additional unlinked members (total 20 unlinked)
+      for i <- 6..20 do
+        Membership.create_member(%{
+          first_name: "Extra#{i}",
+          last_name: "Member#{i}",
+          email: "extra#{i}@example.com"
+        })
+      end
+
+      members =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{})
+        |> Ash.read!()
+
+      # Should be limited to 10
+      assert length(members) == 10
+    end
+
+    test "email match: returns only member with matching email when exists", %{
+      unlinked_members: unlinked_members
+    } do
+      # Get one of the unlinked members' email
+      target_member = List.first(unlinked_members)
+      user_email = target_member.email
+
+      raw_members =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{user_email: user_email})
+        |> Ash.read!()
+
+      # Apply email match filtering (sorted results come from query)
+      # When user_email matches, only that member should be returned
+      members = Mv.Membership.Member.filter_by_email_match(raw_members, user_email)
+
+      # Should return only the member with matching email
+      assert length(members) == 1
+      assert List.first(members).id == target_member.id
+      assert List.first(members).email == user_email
+    end
+
+    test "email match: returns all unlinked members when no email match" do
+      # Use an email that doesn't match any member
+      non_matching_email = "nonexistent@example.com"
+
+      raw_members =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{user_email: non_matching_email})
+        |> Ash.read!()
+
+      # Apply email match filtering
+      members = Mv.Membership.Member.filter_by_email_match(raw_members, non_matching_email)
+
+      # Should return all 5 unlinked members since no match
+      assert length(members) == 5
+    end
+
+    test "search query: filters by first_name, last_name, and email", %{
+      unlinked_members: _unlinked_members
+    } do
+      # Search by first name
+      members =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{search_query: "Alice"})
+        |> Ash.read!()
+
+      assert length(members) == 1
+      assert List.first(members).first_name == "Alice"
+
+      # Search by last name
+      members =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{search_query: "Williams"})
+        |> Ash.read!()
+
+      assert length(members) == 1
+      assert List.first(members).last_name == "Williams"
+
+      # Search by email
+      members =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{search_query: "charlie@"})
+        |> Ash.read!()
+
+      assert length(members) == 1
+      assert List.first(members).email == "charlie@example.com"
+
+      # Search returns empty when no matches
+      members =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{search_query: "NonExistent"})
+        |> Ash.read!()
+
+      assert Enum.empty?(members)
+    end
+
+    test "search query takes precedence over email match", %{unlinked_members: unlinked_members} do
+      target_member = List.first(unlinked_members)
+
+      # Pass both email match and search query that would match different members
+      raw_members =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{
+          user_email: target_member.email,
+          search_query: "Bob"
+        })
+        |> Ash.read!()
+
+      # Search query takes precedence, should match "Bob" in the first name
+      # user_email is used for POST-filtering only, not in the query
+      assert length(raw_members) == 1
+      # Should find the member with "Bob" first name, not target_member (Alice)
+      assert List.first(raw_members).first_name == "Bob"
+      refute List.first(raw_members).id == target_member.id
+    end
+  end
+end
diff --git a/test/membership/member_fuzzy_search_linking_test.exs b/test/membership/member_fuzzy_search_linking_test.exs
new file mode 100644
index 0000000..fcaf5fd
--- /dev/null
+++ b/test/membership/member_fuzzy_search_linking_test.exs
@@ -0,0 +1,158 @@
+defmodule Mv.Membership.MemberFuzzySearchLinkingTest do
+  @moduledoc """
+  Tests fuzzy search in Member.available_for_linking action.
+  Verifies PostgreSQL trigram matching for member search.
+  """
+
+  use Mv.DataCase, async: true
+
+  alias Mv.Accounts
+  alias Mv.Membership
+
+  describe "available_for_linking with fuzzy search" do
+    test "finds member despite typo" do
+      # Create member with specific name
+      {:ok, member} =
+        Membership.create_member(%{
+          first_name: "Jonathan",
+          last_name: "Smith",
+          email: "jonathan@example.com"
+        })
+
+      # Search with typo
+      query =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{
+          user_email: nil,
+          search_query: "Jonatan"
+        })
+
+      {:ok, members} = Ash.read(query, domain: Mv.Membership)
+
+      # Should find Jonathan despite typo
+      assert length(members) == 1
+      assert hd(members).id == member.id
+    end
+
+    test "finds member with partial match" do
+      # Create member
+      {:ok, member} =
+        Membership.create_member(%{
+          first_name: "Alexander",
+          last_name: "Williams",
+          email: "alex@example.com"
+        })
+
+      # Search with partial
+      query =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{
+          user_email: nil,
+          search_query: "Alex"
+        })
+
+      {:ok, members} = Ash.read(query, domain: Mv.Membership)
+
+      # Should find Alexander
+      assert length(members) == 1
+      assert hd(members).id == member.id
+    end
+
+    test "email match overrides fuzzy search" do
+      # Create two members
+      {:ok, member1} =
+        Membership.create_member(%{
+          first_name: "John",
+          last_name: "Doe",
+          email: "john@example.com"
+        })
+
+      {:ok, _member2} =
+        Membership.create_member(%{
+          first_name: "Jane",
+          last_name: "Smith",
+          email: "jane@example.com"
+        })
+
+      # Search with user_email that matches member1, but search_query that would match member2
+      query =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{
+          user_email: "john@example.com",
+          search_query: "Jane"
+        })
+
+      {:ok, members} = Ash.read(query, domain: Mv.Membership)
+
+      # Apply email filter
+      filtered_members = Mv.Membership.Member.filter_by_email_match(members, "john@example.com")
+
+      # Should only return member1 (email match takes precedence)
+      assert length(filtered_members) == 1
+      assert hd(filtered_members).id == member1.id
+    end
+
+    test "limits to 10 results" do
+      # Create 15 members with similar names
+      for i <- 1..15 do
+        Membership.create_member(%{
+          first_name: "Test#{i}",
+          last_name: "Member",
+          email: "test#{i}@example.com"
+        })
+      end
+
+      # Search for "Test"
+      query =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{
+          user_email: nil,
+          search_query: "Test"
+        })
+
+      {:ok, members} = Ash.read(query, domain: Mv.Membership)
+
+      # Should return max 10 members
+      assert length(members) == 10
+    end
+
+    test "excludes linked members" do
+      # Create member and link to user
+      {:ok, member1} =
+        Membership.create_member(%{
+          first_name: "Linked",
+          last_name: "Member",
+          email: "linked@example.com"
+        })
+
+      {:ok, _user} =
+        Accounts.create_user(%{
+          email: "user@example.com",
+          member: %{id: member1.id}
+        })
+
+      # Create unlinked member
+      {:ok, member2} =
+        Membership.create_member(%{
+          first_name: "Unlinked",
+          last_name: "Member",
+          email: "unlinked@example.com"
+        })
+
+      # Search for "Member"
+      query =
+        Mv.Membership.Member
+        |> Ash.Query.for_read(:available_for_linking, %{
+          user_email: nil,
+          search_query: "Member"
+        })
+
+      {:ok, members} = Ash.read(query, domain: Mv.Membership)
+
+      # Should only return unlinked member
+      member_ids = Enum.map(members, & &1.id)
+      refute member1.id in member_ids
+      assert member2.id in member_ids
+    end
+  end
+end