fix(mysql/splitter): distinguish IF control flow from IF() with parenthesized conditions

sqle/driver/mysql/splitter/block.go

@@ -11,6 +11,10 @@ type Block interface {
 	MatchEnd(token *parser.Token) bool
 }
 
+func isThenToken(token *parser.Token) bool {
+	return strings.ToUpper(token.Ident()) == "THEN"
+}
+
 var allBlocks []Block = []Block{
 	BeginEndBlock{},
 	IfEndIfBlock{},

sqle/driver/mysql/splitter/splitter.go

@@ -187,19 +187,13 @@ func (s *splitter) skipBeginEndBlock(token *parser.Token) *parser.Token {
 			}
 		}
 		if matchedBlock != nil {
-			// 如果匹配到的是 IF 块，需要向前看一个 token 来确定它是一个控制流语句还是一个函数。
+			// 如果匹配到的是 IF 块，需要向前看以区分控制流 IF 与 IF() 函数。
+			// 此处 scanner 正位于 IF 之后（currentOffset），前向扫描后需复位以便后续 END 检测。
 			if _, ok := matchedBlock.(IfEndIfBlock); ok {
-				// 向前看一个 token
-				nextToken := s.scanner.NextToken()
-				// **非常重要**：将扫描器位置恢复，以便后续逻辑可以重新处理这个 token
-				s.scanner.SetCursor(currentOffset)
-
-				if nextToken.Ident() == "(" {
-					// 如果 IF 后面是 '('，说明是 IF() 函数，而不是块语句，继续处理下一个 token。
-				} else {
-					// 否则，它是一个真正的 IF 块语句，将其压入堆栈。
+				if s.ifIsControlFlowStatement() {
 					blockStack = append(blockStack, matchedBlock)
 				}
+				s.scanner.SetCursor(currentOffset)
 			} else {
 				// 对于其他类型的块，直接压入堆栈
 				blockStack = append(blockStack, matchedBlock)
@@ -235,6 +229,28 @@ func (s *splitter) skipBeginEndBlock(token *parser.Token) *parser.Token {
 	return token
 }
 
+// ifIsControlFlowStatement 从 IF 之后向前看，判断是控制流 IF 块还是 IF() 函数。
+// 规则：跟踪括号深度，若在深度 0 处遇到 THEN，则为控制流 IF。
+func (s *splitter) ifIsControlFlowStatement() bool {
+	depth := 0
+	for s.scanner.Offset() < len(s.scanner.Text()) {
+		token := s.scanner.NextToken()
+		switch token.Ident() {
+		case "(":
+			depth++
+		case ")":
+			if depth > 0 {
+				depth--
+			}
+		default:
+			if isThenToken(token) && depth == 0 {
+				return true
+			}
+		}
+	}
+	return false
+}
+
 // isBeginQuit 判断BEGIN语句跟的是否就是结束符
 func (s *splitter) isBeginQuit(token *parser.Token, tokenIndex int) bool {
 	if token.Ident() == s.delimiter.DelimiterStr && tokenIndex == 1 {

sqle/driver/mysql/splitter/splitter_test.go

@@ -1426,3 +1426,104 @@ SELECT * FROM users;`,
 		})
 	}
 }
+
+// TestIfControlFlowStatementInProcedure 测试 IF 控制流与 IF() 函数在存储过程中的拆分。
+func TestIfControlFlowStatementInProcedure(t *testing.T) {
+	parser := NewSplitter()
+
+	testCases := []struct {
+		name     string
+		sql      string
+		expected int
+		contains string
+	}{
+		{
+			name: "IF with parenthesized condition in procedure",
+			sql: `CREATE PROCEDURE test_proc(IN Arg0 INT)
+BEGIN
+    DECLARE v_lng DECIMAL(10,6);
+    DECLARE v_lat DECIMAL(10,6);
+    IF ( v_lng IS NULL OR v_lat IS NULL ) AND Arg0 IS NOT NULL THEN
+        SET v_lng = 0;
+    END IF;
+END;`,
+			expected: 1,
+			contains: "END;",
+		},
+		{
+			name: "IF without parenthesized condition in procedure",
+			sql: `CREATE PROCEDURE test_proc()
+BEGIN
+    DECLARE v_variable INT DEFAULT 0;
+    IF v_variable = 0 THEN
+        SET v_variable = 1;
+    END IF;
+END;`,
+			expected: 1,
+			contains: "END;",
+		},
+		{
+			name: "IF with ELSEIF in procedure",
+			sql: `CREATE PROCEDURE test_proc()
+BEGIN
+    DECLARE v_variable INT DEFAULT 0;
+    IF v_variable = 0 THEN
+        SET v_variable = 1;
+    ELSEIF v_variable = 1 THEN
+        SET v_variable = 2;
+    ELSE
+        SET v_variable = 0;
+    END IF;
+END;`,
+			expected: 1,
+			contains: "END;",
+		},
+		{
+			name: "IF function in trigger body",
+			sql: `CREATE TRIGGER trg BEFORE INSERT ON account
+FOR EACH ROW
+BEGIN
+    SET @deposits = @deposits + IF(NEW.amount>0,NEW.amount,0);
+END;`,
+			expected: 1,
+			contains: "IF(NEW.amount>0,NEW.amount,0)",
+		},
+		{
+			name: "IF function with nested CASE THEN in arguments",
+			sql: `CREATE TRIGGER trg BEFORE INSERT ON account
+FOR EACH ROW
+BEGIN
+    SET @x = IF(CASE WHEN NEW.amount > 0 THEN 1 ELSE 0 END, NEW.amount, 0);
+END;`,
+			expected: 1,
+			contains: "IF(CASE WHEN NEW.amount > 0 THEN 1 ELSE 0 END, NEW.amount, 0)",
+		},
+		{
+			name: "procedure followed by select",
+			sql: `CREATE PROCEDURE test_proc()
+BEGIN
+    IF ( 1 = 1 ) AND 2 > 0 THEN
+        SELECT 1;
+    END IF;
+END;
+SELECT 1;`,
+			expected: 2,
+			contains: "END;",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			stmts, err := parser.ParseSqlText(tc.sql)
+			if err != nil {
+				t.Fatalf("解析失败: %v", err)
+			}
+			if len(stmts) != tc.expected {
+				t.Fatalf("期望分割出 %d 个语句，实际得到 %d 个", tc.expected, len(stmts))
+			}
+			if tc.contains != "" && !strings.Contains(stmts[0].Text(), tc.contains) {
+				t.Fatalf("第一条语句应包含 %q，实际为: %s", tc.contains, stmts[0].Text())
+			}
+		})
+	}
+}