From 22b4d37480ff93719acd196b0e41469c87805846 Mon Sep 17 00:00:00 2001
From: Shinichi Maeshima <netwillnet@gmail.com>
Date: Mon, 22 Jun 2026 19:00:14 +0900
Subject: [PATCH] Fix flaky tests
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## Summary

Fix an order-dependent PostgreSQL test failure caused by the `upsert_all` test leaving the `users` primary key sequence out of sync.

## Details

The `upsert_all with different value formats works correctly` test inserts rows with explicit primary keys:

```ruby
{ id: 1, ... }
{ id: 2, ... }
{ id: 3, ... }
```

On PostgreSQL, inserting or upserting rows with explicit IDs does not advance the table’s primary key sequence. As a result, later tests that create `User` records without specifying an ID can receive an already-used ID from the sequence, causing errors like:

```text
PG::UniqueViolation: duplicate key value violates unique constraint "users_pkey"
```

This failure depends on randomized test order. In the failing CI run, the `upsert_all` test ran before tests that performed normal `User.create!` / `save!` calls.

## Fix

Wrap the `upsert_all` test in an `ensure` block and reset the primary key sequence afterward when the adapter supports it:

```ruby
User.connection.reset_pk_sequence!(User.table_name) if User.connection.respond_to?(:reset_pk_sequence!)
```

Using `ensure` makes sure the sequence is reset even if the test fails partway through, preventing this test from leaking database state into later tests.

## Verification

Reproduced with PostgreSQL using the CI seed:

```
POSTGRES_USER=postgres \
POSTGRES_PASSWORD=postgres \
DB=postgresql \
bundle exec ruby -w -Ilib:test test/activerecord_test.rb --seed 40802
```

result example

```
  1) Error:
ActiveRecordTest#test_0028_stores multiple value passed passed to new:
ActiveRecord::RecordNotUnique: PG::UniqueViolation: ERROR:  duplicate key value violates unique constraint "users_pkey"
DETAIL:  Key (id)=(2) already exists.

# … snip …

  2) Error:
ActiveRecordTest#test_0044_does not change by the practical same value:
ActiveRecord::RecordNotUnique: PG::UniqueViolation: ERROR:  duplicate key value violates unique constraint "users_pkey"
DETAIL:  Key (id)=(3) already exists.
# … snip …
```
---
 test/activerecord_test.rb | 46 +++++++++++++++++++++------------------
 1 file changed, 25 insertions(+), 21 deletions(-)

diff --git a/test/activerecord_test.rb b/test/activerecord_test.rb
index 5fdc213..a1d6f5d 100644
--- a/test/activerecord_test.rb
+++ b/test/activerecord_test.rb
@@ -834,26 +834,30 @@ class AdminUser < User
   it 'upsert_all with different value formats works correctly' do
     User.delete_all
 
-    User.upsert_all([
-      { id: 1, sex: :male, status: 1 },
-      { id: 2, sex: 'female', status: :blocked }
-    ])
-
-    User.upsert_all([
-      { id: 1, sex: 'male', status: :active },
-      { id: 3, sex: :female, status: 2 }
-    ])
-
-    users = User.order(:id).to_a
-    expect(users.size).must_equal 3
-    
-    expect(users[0].sex).must_equal 'male'
-    expect(users[0].status).must_equal 'active'
-    
-    expect(users[1].sex).must_equal 'female'
-    expect(users[1].status).must_equal 'blocked'
-    
-    expect(users[2].sex).must_equal 'female'
-    expect(users[2].status).must_equal 'blocked'
+    begin
+      User.upsert_all([
+        { id: 1, sex: :male, status: 1 },
+        { id: 2, sex: 'female', status: :blocked }
+      ])
+
+      User.upsert_all([
+        { id: 1, sex: 'male', status: :active },
+        { id: 3, sex: :female, status: 2 }
+      ])
+
+      users = User.order(:id).to_a
+      expect(users.size).must_equal 3
+
+      expect(users[0].sex).must_equal 'male'
+      expect(users[0].status).must_equal 'active'
+
+      expect(users[1].sex).must_equal 'female'
+      expect(users[1].status).must_equal 'blocked'
+
+      expect(users[2].sex).must_equal 'female'
+      expect(users[2].status).must_equal 'blocked'
+    ensure
+      User.connection.reset_pk_sequence!(User.table_name) if User.connection.respond_to?(:reset_pk_sequence!)
+    end
   end
 end