Add string concat test

execution/execute_test.go

@@ -196,6 +196,11 @@ func TestExecuteSelector_HappyPath(t *testing.T) {
 			s:   `name.first`,
 			out: model.NewStringValue("Tom"),
 		}))
+		t.Run("concat", runTest(testCase{
+			in:  inputMap(),
+			s:   `title + " " + (name.first) + " " + (name.last)`,
+			out: model.NewStringValue("Mr Tom Wright"),
+		}))
 	})
 
 	t.Run("object", func(t *testing.T) {

selector/parser/parse_group.go

@@ -21,6 +21,11 @@ func parseGroup(p *Parser) (ast.Expr, error) {
 			break
 		}
 
+		if p.current().IsKind(lexer.Dot) {
+			p.advance()
+			continue
+		}
+
 		expr, err := p.parseExpression(bpDefault)
 		if err != nil {
 			return nil, err

selector/parser/parser.go

@@ -53,7 +53,7 @@ func (p *Parser) endOfExpressionTokens() []lexer.TokenKind {
 	case scopeObject:
 		return []lexer.TokenKind{lexer.CloseCurly, lexer.Equals, lexer.Number, lexer.Symbol, lexer.Comma}
 	case scopeGroup:
-		return []lexer.TokenKind{lexer.CloseParen}
+		return append([]lexer.TokenKind{lexer.CloseParen, lexer.Dot}, leftDenotationTokens...)
 	default:
 		return nil
 	}