feat (db): add Writer.IsTx(...) (#3770)

internal/db/read_writer.go

@@ -77,6 +77,9 @@ type Writer interface {
 	// DoTx will wrap the TxHandler in a retryable transaction
 	DoTx(ctx context.Context, retries uint, backOff Backoff, Handler TxHandler) (RetryInfo, error)
 
+	// IsTx returns true if there's an existing transaction in progress
+	IsTx(ctx context.Context) bool
+
 	// Update an object in the db, fieldMask is required and provides
 	// field_mask.proto paths for fields that should be updated. The i interface
 	// parameter is the type the caller wants to update in the db and its
@@ -457,6 +460,11 @@ func (rw *Db) DoTx(ctx context.Context, retries uint, backOff Backoff, handler T
 	}
 }
 
+// IsTx returns true if there's an existing transaction in progress
+func (rw *Db) IsTx(_ context.Context) bool {
+	return dbw.New(rw.underlying.wrapped.Load()).IsTx()
+}
+
 // LookupByPublicId will lookup resource by its public_id or private_id, which
 // must be unique. WithDebug is the only valid option, all other options are ignored.
 func (rw *Db) LookupById(ctx context.Context, resourceWithIder any, opt ...Option) error {

internal/db/read_writer_ext_test.go

@@ -235,3 +235,21 @@ func TestDb_Create_OnConflict(t *testing.T) {
 		assert.Equal(conflictUser.Name, foundUser.Name)
 	})
 }
+
+func TestRW_IsTx(t *testing.T) {
+	t.Parallel()
+	testCtx := context.Background()
+	conn, _ := db.TestSetup(t, "postgres")
+	rw := db.New(conn)
+
+	assert, require := assert.New(t), require.New(t)
+
+	assert.False(rw.IsTx(testCtx))
+
+	_, err := rw.DoTx(context.Background(), 10, db.ExpBackoff{},
+		func(_ db.Reader, txWriter db.Writer) error {
+			assert.True(txWriter.IsTx(testCtx))
+			return nil
+		})
+	require.NoError(err)
+}