fix: parse adjacent set_by_lua_block opening brace

lex_test.go

@@ -9,6 +9,7 @@ package crossplane
 
 import (
 	"os"
+	"reflect"
 	"strings"
 	"testing"
 )
@@ -446,6 +447,65 @@ func TestLex(t *testing.T) {
 	}
 }
 
+func TestLex_setByLuaBlockOpeningBraceDelimiter(t *testing.T) {
+	t.Parallel()
+
+	testcases := []struct {
+		name        string
+		config      string
+		expectedArg string
+	}{
+		{
+			name:        "whitespace before opening brace",
+			config:      `set_by_lua_block $pass { return { ok = true } }`,
+			expectedArg: "$pass",
+		},
+		{
+			name:        "opening brace adjacent to output variable",
+			config:      `set_by_lua_block $pass{ return { ok = true } }`,
+			expectedArg: "$pass",
+		},
+		{
+			name:        "whitespace after braced variable",
+			config:      `set_by_lua_block ${pass} { return { ok = true } }`,
+			expectedArg: "${pass}",
+		},
+		{
+			name:        "opening brace adjacent to braced variable",
+			config:      `set_by_lua_block ${pass}{ return { ok = true } }`,
+			expectedArg: "${pass}",
+		},
+	}
+
+	for _, testcase := range testcases {
+		testcase := testcase
+		t.Run(testcase.name, func(t *testing.T) {
+			t.Parallel()
+
+			var actual []string
+			options := LexOptions{
+				Lexers: []RegisterLexer{lua.RegisterLexer()},
+			}
+			for token := range LexWithOptions(strings.NewReader(testcase.config), options) {
+				if token.Error != nil {
+					t.Fatal(token.Error)
+				}
+				actual = append(actual, token.Value)
+			}
+
+			expected := []string{
+				setByLuaBlock,
+				testcase.expectedArg,
+				" return { ok = true } ",
+				";",
+			}
+			if !reflect.DeepEqual(actual, expected) {
+				t.Fatalf("expected tokens %#v, got %#v", expected, actual)
+			}
+		})
+	}
+}
+
 func TestLex_unhappy(t *testing.T) {
 	t.Parallel()
 

lua.go

@@ -72,6 +72,13 @@ func (l *Lua) Lex(s *SubScanner, matchedToken string) <-chan NgxToken {
 					return
 				}
 				next := s.Text()
+				// NGINX treats an opening brace as the end of the current argument,
+				// except when it starts a parameter expansion such as ${variable}.
+				if next == "{" && arg != "" && !strings.HasSuffix(arg, "$") {
+					tokenCh <- NgxToken{Value: arg, Line: s.Line(), IsQuoted: false}
+					tokenDepth++
+					break
+				}
 				if isSpace(next) {
 					if arg != "" {
 						tokenCh <- NgxToken{Value: arg, Line: s.Line(), IsQuoted: false}
@@ -90,20 +97,22 @@ func (l *Lua) Lex(s *SubScanner, matchedToken string) <-chan NgxToken {
 		}
 
 		// check that Lua block starts correctly
-		for {
-			if !s.Scan() {
-				return
-			}
-			next := s.Text()
-
-			if !isSpace(next) {
-				if next != "{" {
-					lineno := s.Line()
-					tokenCh <- NgxToken{Error: &ParseError{File: &lexerFile, What: `expected "{" to start lua block`, Line: &lineno}}
+		if tokenDepth == 0 {
+			for {
+				if !s.Scan() {
 					return
 				}
-				tokenDepth++
-				break
+				next := s.Text()
+
+				if !isSpace(next) {
+					if next != "{" {
+						lineno := s.Line()
+						tokenCh <- NgxToken{Error: &ParseError{File: &lexerFile, What: `expected "{" to start lua block`, Line: &lineno}}
+						return
+					}
+					tokenDepth++
+					break
+				}
 			}
 		}