feat(interceptor): add BegixTx callback

Makefile

@@ -1,29 +1,37 @@
 .POSIX:
 .SUFFIXES:
 
-fmt:
-	@golangci-lint fmt
+bench:
+	@go test -run='^$$' -bench=. -cpuprofile=profile.cpu -memprofile=profile.mem
 
-gen:
-	@go generate ./...
+clean:
+	@rm -rf tests/coverdata tests/coverage.out tests/test.sqlite
 
 deps:
 	@go mod tidy
 	@cd tests && go mod tidy
 
+fmt:
+	@golangci-lint fmt
+
+gen:
+	@go generate ./...
+
 lint:
 	@golangci-lint run
 
-test:
-	@rm -rf tests/coverdata tests/coverage.out tests/test.sqlite && mkdir tests/coverdata
+test: test/unit test/integration
+
+test/unit: clean
+	@mkdir -p tests/coverdata
 	@go test -race -shuffle=on -cover . -args -test.gocoverdir=$$PWD/tests/coverdata
+
+test/integration: clean
+	@mkdir -p tests/coverdata
 	@$(CONTAINER_RUNNER) compose --file=tests/compose.yaml up --detach
 	@go test -v -race -coverpkg=go-simpler.org/queries ./tests -args -test.gocoverdir=$$PWD/tests/coverdata
 	@$(CONTAINER_RUNNER) compose --file=tests/compose.yaml down
 	@go tool covdata textfmt -i=tests/coverdata -o=tests/coverage.out
 
 test/cover: test
 	@go tool cover -html=tests/coverage.out
-
-bench:
-	@go test -run='^$$' -bench=. -cpuprofile=profile.cpu -memprofile=profile.mem

interceptor.go

@@ -26,7 +26,6 @@ var (
 // Otherwise, it prepares a [driver.Stmt] using [driver.ConnPrepareContext], executes it, and closes it.
 // In such cases, you may want to implement both the PrepareContext and ExecContext/QueryContext callbacks,
 // even if you don't prepare statements manually via [sql.DB.PrepareContext].
-// TODO: provide an example of such an implementation.
 //
 // [go-sql-driver/mysql]: https://github.com/go-sql-driver/mysql
 type Interceptor struct {
@@ -49,6 +48,10 @@ type Interceptor struct {
 	// PrepareContext is a callback for [sql.DB.PrepareContext] and [sql.Tx.PrepareContext].
 	// The implementation must call preparer.ConnPrepareContext(ctx, query) and return the result.
 	PrepareContext func(ctx context.Context, query string, preparer driver.ConnPrepareContext) (driver.Stmt, error)
+
+	// BeginTx is a callback for [sql.DB.BeginTx].
+	// The implementation must call beginner.BeginTx(ctx, opts) and return the result.
+	BeginTx func(ctx context.Context, opts driver.TxOptions, beginner driver.ConnBeginTx) (driver.Tx, error)
 }
 
 // Open implements [driver.Driver].
@@ -134,6 +137,9 @@ func (c wrappedConn) BeginTx(ctx context.Context, opts driver.TxOptions) (driver
 	if !ok {
 		panic("queries: driver does not implement driver.ConnBeginTx")
 	}
+	if c.interceptor.BeginTx != nil {
+		return c.interceptor.BeginTx(ctx, opts, beginner)
+	}
 	return beginner.BeginTx(ctx, opts)
 }
 

interceptor_test.go

@@ -18,6 +18,7 @@ func TestInterceptor(t *testing.T) {
 	var execCalled bool
 	var queryCalled bool
 	var prepareCalled bool
+	var beginTxCalled bool
 
 	interceptor := queries.Interceptor{
 		Driver: mockDriver{conn: spyConn{}},
@@ -33,9 +34,13 @@ func TestInterceptor(t *testing.T) {
 			prepareCalled = true
 			return preparer.PrepareContext(ctx, query)
 		},
+		BeginTx: func(ctx context.Context, opts driver.TxOptions, beginner driver.ConnBeginTx) (driver.Tx, error) {
+			beginTxCalled = true
+			return beginner.BeginTx(ctx, opts)
+		},
 	}
 
-	driverName := t.Name() + "_interceptor"
+	driverName := t.Name()
 	sql.Register(driverName, interceptor)
 
 	db, err := sql.Open(driverName, "")
@@ -53,6 +58,10 @@ func TestInterceptor(t *testing.T) {
 	_, err = db.PrepareContext(ctx, "")
 	assert.IsErr[E](t, err, errCalled)
 	assert.Equal[E](t, prepareCalled, true)
+
+	_, err = db.BeginTx(ctx, nil)
+	assert.IsErr[E](t, err, errCalled)
+	assert.Equal[E](t, beginTxCalled, true)
 }
 
 func TestInterceptor_passthrough(t *testing.T) {
@@ -62,7 +71,7 @@ func TestInterceptor_passthrough(t *testing.T) {
 		Driver: mockDriver{conn: spyConn{}},
 	}
 
-	driverName := t.Name() + "_interceptor"
+	driverName := t.Name()
 	sql.Register(driverName, interceptor)
 
 	db, err := sql.Open(driverName, "")
@@ -77,6 +86,9 @@ func TestInterceptor_passthrough(t *testing.T) {
 
 	_, err = db.PrepareContext(ctx, "")
 	assert.IsErr[E](t, err, errCalled)
+
+	_, err = db.BeginTx(ctx, nil)
+	assert.IsErr[E](t, err, errCalled)
 }
 
 func TestInterceptor_unimplemented(t *testing.T) {
@@ -86,7 +98,7 @@ func TestInterceptor_unimplemented(t *testing.T) {
 		Driver: mockDriver{conn: unimplementedConn{}},
 	}
 
-	driverName := t.Name() + "_interceptor"
+	driverName := t.Name()
 	sql.Register(driverName, interceptor)
 
 	db, err := sql.Open(driverName, "")
@@ -113,7 +125,7 @@ func TestInterceptor_driver(t *testing.T) {
 	mdriver := mockDriver{}
 	interceptor := queries.Interceptor{Driver: mdriver}
 
-	driverName := t.Name() + "_interceptor"
+	driverName := t.Name()
 	sql.Register(driverName, interceptor)
 
 	db, err := sql.Open(driverName, "")
@@ -148,3 +160,7 @@ func (spyConn) QueryContext(context.Context, string, []driver.NamedValue) (drive
 func (spyConn) PrepareContext(context.Context, string) (driver.Stmt, error) {
 	return nil, errCalled
 }
+
+func (spyConn) BeginTx(context.Context, driver.TxOptions) (driver.Tx, error) {
+	return nil, errCalled
+}

tests/integration_test.go

@@ -99,6 +99,7 @@ func TestIntegration(t *testing.T) {
 				var execCalls int
 				var queryCalls int
 				var prepareCalls int
+				var beginTxCalls int
 
 				interceptor := queries.Interceptor{
 					Driver: driverIface,
@@ -117,6 +118,11 @@ func TestIntegration(t *testing.T) {
 						t.Logf("PrepareContext: %s", query)
 						return preparer.PrepareContext(ctx, query)
 					},
+					BeginTx: func(ctx context.Context, opts driver.TxOptions, beginner driver.ConnBeginTx) (driver.Tx, error) {
+						beginTxCalls++
+						t.Log("BeginTx")
+						return beginner.BeginTx(ctx, opts)
+					},
 				}
 
 				driverName += "+interceptor"
@@ -187,14 +193,17 @@ func TestIntegration(t *testing.T) {
 					assert.Equal[E](t, execCalls, 3)
 					assert.Equal[E](t, queryCalls, 5*2)
 					assert.Equal[E](t, prepareCalls, 1)
+					assert.Equal[E](t, beginTxCalls, 1)
 				case *mssqldb.Driver: // always uses PrepareContext.
 					assert.Equal[E](t, execCalls, 0)
 					assert.Equal[E](t, queryCalls, 0)
 					assert.Equal[E](t, prepareCalls, 3+5*2)
+					assert.Equal[E](t, beginTxCalls, 1)
 				default:
 					assert.Equal[E](t, execCalls, 3)
 					assert.Equal[E](t, queryCalls, 5*2)
 					assert.Equal[E](t, prepareCalls, 0)
+					assert.Equal[E](t, beginTxCalls, 1)
 				}
 			})
 		}