feat: prevent join requests with equal mail

test/membership/join_request_approval_domain_test.exs

@@ -67,6 +67,18 @@ defmodule Mv.Membership.JoinRequestApprovalDomainTest do
     end
   end
 
+  describe "reviewed_by_display" do
+    test "get_join_request returns reviewed_by_display so UI can show reviewer without loading User" do
+      request = Fixtures.submitted_join_request_fixture()
+      reviewer = Fixtures.user_with_role_fixture("normal_user")
+
+      assert {:ok, _} = Membership.approve_join_request(request.id, actor: reviewer)
+
+      assert {:ok, loaded} = Membership.get_join_request(request.id, actor: reviewer)
+      assert loaded.reviewed_by_display == to_string(reviewer.email)
+    end
+  end
+
   describe "reject_join_request/2" do
     test "reject does not create a member" do
       request = Fixtures.submitted_join_request_fixture()

test/membership/join_request_approval_policy_test.exs

@@ -49,6 +49,7 @@ defmodule Mv.Membership.JoinRequestApprovalPolicyTest do
       assert approved.status == :approved
       assert approved.approved_at != nil
       assert approved.reviewed_by_user_id == user.id
+      assert approved.reviewed_by_display == to_string(user.email)
     end
 
     test "admin can approve a submitted join request", %{request: request} do
@@ -89,6 +90,7 @@ defmodule Mv.Membership.JoinRequestApprovalPolicyTest do
       assert rejected.status == :rejected
       assert rejected.rejected_at != nil
       assert rejected.reviewed_by_user_id == user.id
+      assert rejected.reviewed_by_display == to_string(user.email)
     end
 
     test "admin can reject a submitted join request", %{request: request} do

test/membership/join_request_test.exs

@@ -12,7 +12,12 @@ defmodule Mv.Membership.JoinRequestTest do
   """
   use Mv.DataCase, async: true
 
+  require Ash.Query
+  import Ash.Expr
+
+  alias Mv.Fixtures
   alias Mv.Membership
+  alias Mv.Membership.JoinRequest
 
   # Valid minimal attributes for submit (email required; confirmation_token optional for tests)
   @valid_submit_attrs %{
@@ -136,6 +141,60 @@ defmodule Mv.Membership.JoinRequestTest do
     end
   end
 
+  describe "submit_join_request/2 anti-enumeration (already member / already pending)" do
+    test "returns {:ok, :notified_already_member} and creates no JoinRequest when email is already a member" do
+      member =
+        Fixtures.member_fixture(%{
+          email: "already_member#{System.unique_integer([:positive])}@example.com"
+        })
+
+      attrs = %{
+        email: member.email,
+        confirmation_token: "token-#{System.unique_integer([:positive])}"
+      }
+
+      assert {:ok, :notified_already_member} = Membership.submit_join_request(attrs, actor: nil)
+
+      system_actor = Mv.Helpers.SystemActor.get_system_actor()
+
+      {:ok, requests} =
+        JoinRequest
+        |> Ash.Query.filter(expr(email == ^member.email))
+        |> Ash.read(actor: system_actor, domain: Mv.Membership)
+
+      assert requests == []
+    end
+
+    test "returns {:ok, :notified_already_pending} and does not create duplicate when same email submits again (resend)" do
+      email = "resend#{System.unique_integer([:positive])}@example.com"
+      token1 = "first-token-#{System.unique_integer([:positive])}"
+      attrs1 = %{email: email, confirmation_token: token1}
+
+      assert {:ok, request1} = Membership.submit_join_request(attrs1, actor: nil)
+      assert request1.status == :pending_confirmation
+
+      attrs2 = %{
+        email: email,
+        confirmation_token: "second-token-#{System.unique_integer([:positive])}"
+      }
+
+      assert {:ok, :notified_already_pending} = Membership.submit_join_request(attrs2, actor: nil)
+
+      system_actor = Mv.Helpers.SystemActor.get_system_actor()
+
+      {:ok, requests} =
+        JoinRequest
+        |> Ash.Query.filter(expr(email == ^email))
+        |> Ash.read(actor: system_actor, domain: Mv.Membership)
+
+      assert length(requests) == 1
+      assert hd(requests).id == request1.id
+
+      # Resend path updates the request (new token stored); confirmation_sent_at will have been set/updated
+      assert hd(requests).confirmation_sent_at != nil
+    end
+  end
+
   describe "allowlist (server-side field filter)" do
     test "submit with non-allowlisted form_data keys does not persist those keys" do
       # Allowlist restricts which fields are accepted; extra keys must not be stored.