test: restore SQLite statistics after plan tests

The two SQLite plan tests ran ANALYZE and then deleted every row in
sqlite_stat1. A run against a SQLite database with its own statistics
lost them, so later queries in that database could choose different
plans.

restoring_sqlite_statistics now saves each sqlite_stat table before
the block, puts the saved rows back, reloads the statistics, and drops
the statistics tables that the block created.

Author: cardmagic

test/database_test_helper.rb

@@ -83,6 +83,30 @@ def suspend_sqlite_busy_wait(connection)
     connection.raw_connection.busy_handler_timeout = configured_sqlite_busy_handler_timeout
   end
 
+  def restoring_sqlite_statistics(connection)
+    saved = sqlite_statistics_tables(connection).to_h { |table| [ table, connection.select_all("SELECT * FROM #{table}") ] }
+    yield
+  ensure
+    restore_sqlite_statistics(connection, saved) if saved
+  end
+
+  def restore_sqlite_statistics(connection, saved)
+    database = connection.raw_connection
+    saved.each do |table, statistics|
+      placeholders = Array.new(statistics.columns.length, "?").join(", ")
+      database.execute("DELETE FROM #{table}")
+      statistics.rows.each do |row|
+        database.execute("INSERT INTO #{table} (#{statistics.columns.join(", ")}) VALUES (#{placeholders})", row)
+      end
+    end
+    database.execute("ANALYZE sqlite_schema")
+    (sqlite_statistics_tables(connection) - saved.keys).each { |table| database.execute("DROP TABLE #{table}") }
+  end
+
+  def sqlite_statistics_tables(connection)
+    connection.select_values("SELECT name FROM sqlite_schema WHERE type = 'table' AND name LIKE 'sqlite\\_stat%' ESCAPE '\\'")
+  end
+
   def configured_sqlite_busy_handler_timeout
     SolidObjects::Record
       .connection_pool

test/integration/activation_candidates_test.rb

@@ -38,23 +38,22 @@ def run
     skip "requires a SQLite query plan" unless database_family == :sqlite
 
     now = SolidObjects.database_adapter.database_now
-    SolidObjects::Instance.insert_all!(Array.new(3_000) { |index|
-      { actor_type: "activation-candidates", actor_id: "idle-#{index}", state: {}, created_at: now, updated_at: now }
-    })
     connection = SolidObjects::Record.connection
-    connection.execute("ANALYZE")
-    analyzed_tables = connection.select_values("SELECT DISTINCT tbl FROM sqlite_stat1")
+    restoring_sqlite_statistics(connection) do
+      SolidObjects::Instance.insert_all!(Array.new(3_000) { |index|
+        { actor_type: "activation-candidates", actor_id: "idle-#{index}", state: {}, created_at: now, updated_at: now }
+      })
+      connection.execute("ANALYZE")
+      analyzed_tables = connection.select_values("SELECT DISTINCT tbl FROM sqlite_stat1")
 
-    assert_includes analyzed_tables, SolidObjects::Instance.table_name
-    refute_includes analyzed_tables, SolidObjects::ClaimedMessage.table_name
+      assert_includes analyzed_tables, SolidObjects::Instance.table_name
+      refute_includes analyzed_tables, SolidObjects::ClaimedMessage.table_name
 
-    plan = sqlite_query_plan(connection, SolidObjects::ClaimedMessage.table_name) { claimed_instance_ids(now) }
+      plan = sqlite_query_plan(connection, SolidObjects::ClaimedMessage.table_name) { claimed_instance_ids(now) }
 
-    assert_match(/\A(SCAN|SEARCH) #{SolidObjects::ClaimedMessage.table_name}\b/, plan.first, plan.join("\n"))
-    assert plan.none? { |step| step.start_with?("SCAN #{SolidObjects::Instance.table_name}") }, plan.join("\n")
-  ensure
-    connection&.execute("DELETE FROM sqlite_stat1")
-    connection&.execute("ANALYZE sqlite_schema")
+      assert_match(/\A(SCAN|SEARCH) #{SolidObjects::ClaimedMessage.table_name}\b/, plan.first, plan.join("\n"))
+      assert plan.none? { |step| step.start_with?("SCAN #{SolidObjects::Instance.table_name}") }, plan.join("\n")
+    end
   end
 
   private

test/integration/effect_recovery_candidates_test.rb

@@ -44,27 +44,26 @@ def run
 
     now = Time.current
     effect_ids = Array.new(3_000) { SecureRandom.uuid }
-    SolidObjects::Effect.insert_all!(effect_ids.map { |effect_id|
-      { message_id: @message.id, instance_id: @message.instance_id, effect_id:, name: "work", arguments: {},
-        status: "completed", max_attempts: 3, available_at: now, completed_at: now, created_at: now, updated_at: now }
-    })
-    SolidObjects::EffectRecovery.insert_all!(effect_ids.last(300).map { |effect_id|
-      { effect_id:, instance_id: @message.instance_id, recovery_operation: "recover", status_operation: "status",
-        created_at: now, updated_at: now }
-    })
     connection = SolidObjects::Record.connection
-    connection.execute("ANALYZE")
-    poll_statistics = connection.select_value("SELECT stat FROM sqlite_stat1 WHERE idx = 'idx_so_effects_poll'")
-
-    assert_equal 3_000, poll_statistics.split[1].to_i
-
-    plan = connection.select_all("EXPLAIN QUERY PLAN #{recovery_candidates.to_sql}").map { |row| row["detail"] }
-
-    assert_match(/\ASEARCH #{SolidObjects::Effect.table_name} USING INDEX idx_so_effects_poll \(status=\?\)/, plan.first, plan.join("\n"))
-    assert plan.none? { |step| step.start_with?("SCAN ") }, plan.join("\n")
-  ensure
-    connection&.execute("DELETE FROM sqlite_stat1")
-    connection&.execute("ANALYZE sqlite_schema")
+    restoring_sqlite_statistics(connection) do
+      SolidObjects::Effect.insert_all!(effect_ids.map { |effect_id|
+        { message_id: @message.id, instance_id: @message.instance_id, effect_id:, name: "work", arguments: {},
+          status: "completed", max_attempts: 3, available_at: now, completed_at: now, created_at: now, updated_at: now }
+      })
+      SolidObjects::EffectRecovery.insert_all!(effect_ids.last(300).map { |effect_id|
+        { effect_id:, instance_id: @message.instance_id, recovery_operation: "recover", status_operation: "status",
+          created_at: now, updated_at: now }
+      })
+      connection.execute("ANALYZE")
+      poll_statistics = connection.select_value("SELECT stat FROM sqlite_stat1 WHERE idx = 'idx_so_effects_poll'")
+
+      assert_equal 3_000, poll_statistics.split[1].to_i
+
+      plan = connection.select_all("EXPLAIN QUERY PLAN #{recovery_candidates.to_sql}").map { |row| row["detail"] }
+
+      assert_match(/\ASEARCH #{SolidObjects::Effect.table_name} USING INDEX idx_so_effects_poll \(status=\?\)/, plan.first, plan.join("\n"))
+      assert plan.none? { |step| step.start_with?("SCAN ") }, plan.join("\n")
+    end
   end
 
   private