fix parsesql.treeRepr when nil is in input (#18974)

* fix parsesql.treeRepr when nil is in input

* return newNode(nkNone) as default value, not nil

lib/pure/parsesql.nim

@@ -982,7 +982,7 @@ proc parseInsert(p: var SqlParser): SqlNode =
     parseParIdentList(p, n)
     result.add n
   else:
-    result.add(nil)
+    result.add(newNode(nkNone))
   if isKeyw(p, "default"):
     getTok(p)
     eat(p, "values")
@@ -1017,7 +1017,7 @@ proc parseUpdate(p: var SqlParser): SqlNode =
   if isKeyw(p, "where"):
     result.add(parseWhere(p))
   else:
-    result.add(nil)
+    result.add(newNode(nkNone))
 
 proc parseDelete(p: var SqlParser): SqlNode =
   getTok(p)
@@ -1029,7 +1029,7 @@ proc parseDelete(p: var SqlParser): SqlNode =
   if isKeyw(p, "where"):
     result.add(parseWhere(p))
   else:
-    result.add(nil)
+    result.add(newNode(nkNone))
 
 proc parseSelect(p: var SqlParser): SqlNode =
   getTok(p)

tests/stdlib/tparsesql.nim

@@ -3,6 +3,17 @@ discard """
 """
 import parsesql
 
+doAssert treeRepr(parseSql("INSERT INTO STATS VALUES (10, 5.5); ")
+) == """
+
+nkStmtList
+  nkInsert
+    nkIdent STATS
+    nkNone
+    nkValueList
+      nkIntegerLit 10
+      nkNumericLit 5.5"""
+
 doAssert $parseSQL("SELECT foo FROM table;") == "select foo from table;"
 doAssert $parseSQL("""
 SELECT
@@ -183,8 +194,31 @@ SET ContactName = 'Alfred Schmidt', City= 'Frankfurt'
 WHERE CustomerID = 1;
 """) == "update Customers set ContactName  = 'Alfred Schmidt' , City  = 'Frankfurt' where CustomerID = 1;"
 
+doAssert treeRepr(parseSql("""UPDATE Customers
+                              SET ContactName = 'Alice', City= 'Frankfurt';""")
+) == """
+
+nkStmtList
+  nkUpdate
+    nkIdent Customers
+    nkAsgn
+      nkIdent ContactName
+      nkStringLit Alice
+    nkAsgn
+      nkIdent City
+      nkStringLit Frankfurt
+    nkNone"""
+
 doAssert $parseSQL("DELETE FROM table_name;") == "delete from table_name;"
 
+doAssert treeRepr(parseSQL("DELETE FROM table_name;")
+) == """
+
+nkStmtList
+  nkDelete
+    nkIdent table_name
+    nkNone"""
+
 doAssert $parseSQL("DELETE * FROM table_name;") == "delete from table_name;"
 
 doAssert $parseSQL("""