[Issue #16] - Abstracted benchmarks from tests via BenchmarkProfile model, to allow for linking benchmarks with different runtime settings

db/migrations/0004_add_benchmarksettings_table.rb

@@ -0,0 +1,97 @@
+Sequel.migration do
+  up do
+    # 1. Create benchmark_profiles
+    create_table(:benchmark_profiles) do
+      primary_key :id
+			String :label, null: false
+			String :settings, null: false
+      foreign_key :benchmark_id, :benchmarks, null: false, on_delete: :cascade
+			DateTime :created_at, default: Sequel::CURRENT_TIMESTAMP
+      DateTime :updated_at, default: Sequel::CURRENT_TIMESTAMP
+    end
+
+    # 2. Create join table (tests <-> benchmark_profiles)
+    create_table(:benchmark_profiles_tests) do
+      primary_key :id
+      foreign_key :test_id, :tests, null: false, on_delete: :cascade
+      foreign_key :benchmark_profile_id, :benchmark_profiles, null: false, on_delete: :cascade
+
+      index [:test_id, :benchmark_profile_id], unique: true
+    end
+
+    # 3. Add benchmark_profile_id to results
+    alter_table(:results) do
+      add_foreign_key :benchmark_profile_id, :benchmark_profiles, null: true, on_delete: :cascade
+    end
+
+    # 4. Migrate data from old schema
+		from(:benchmarks).each do |b_row|
+      # Create a BenchmarkProfile for this (test, benchmark) pair
+      bp_id = self[:benchmark_profiles].insert(
+				benchmark_id: b_row[:id],
+				label: 'Default',
+				settings: '{}'
+      )
+
+			from(:benchmarks_tests).each do |bt_row|
+				if bt_row[:benchmark_id] == b_row[:id]
+		      # Link it to the test
+		      self[:benchmark_profiles_tests].insert(
+		        test_id: bt_row[:test_id],
+		        benchmark_profile_id: bp_id
+		      )
+
+		      # Update results belonging to this test + benchmark pair
+		      self[:results]
+		        .where(test_id: bt_row[:test_id], benchmark_id: bt_row[:benchmark_id])
+		        .update(benchmark_profile_id: bp_id)
+				end
+			end
+    end
+
+    # 5. Clean up old schema
+    alter_table(:results) do
+      drop_foreign_key :benchmark_id
+    end
+
+    drop_table(:benchmarks_tests)
+  end
+
+  down do
+    # 1. Recreate old join table
+    create_table(:benchmarks_tests) do
+      foreign_key :test_id, :tests, null: false
+      foreign_key :benchmark_id, :benchmarks, null: false
+    end
+
+    # 2. Add benchmark_id back to results
+    alter_table(:results) do
+      add_foreign_key :benchmark_id, :benchmarks, null: true
+    end
+
+    # 3. Restore data
+		from(:benchmark_profiles_tests).each do |bpt_row|
+		  bp = self[:benchmark_profiles][id: bpt_row[:benchmark_profile_id]]
+		  next unless bp  # safety check
+
+		  # Recreate old benchmarks_tests entry
+		  self[:benchmarks_tests].insert(
+		    test_id: bpt_row[:test_id],
+		    benchmark_id: bp[:benchmark_id]
+		  )
+
+		  # Update results to point back to benchmark_id
+		  self[:results]
+		    .where(test_id: bpt_row[:test_id], benchmark_profile_id: bp[:id])
+		    .update(benchmark_id: bp[:benchmark_id])
+		end
+
+    # 4. Remove new schema
+    alter_table(:results) do
+      drop_foreign_key :benchmark_profile_id
+    end
+
+    drop_table(:benchmark_profiles_tests)
+    drop_table(:benchmark_profiles)
+  end
+end