AST: avoid multivalued results for MethodName::getValueText

ql/src/codeql_ruby/ast/Expr.qll

@@ -110,6 +110,12 @@ class StringLiteral extends Literal, @string__ {
 class SymbolLiteral extends Literal {
   final override SymbolLiteral::Range range;
 
+  SymbolLiteral() {
+    not any(UndefStmt u).getAMethodName() = this and
+    not any(AliasStmt a).getNewName() = this and
+    not any(AliasStmt a).getOldName() = this
+  }
+
   final override string getAPrimaryQlClass() { result = "SymbolLiteral" }
 }
 

ql/src/codeql_ruby/ast/internal/Expr.qll

@@ -173,27 +173,33 @@ module SymbolLiteral {
 }
 
 module MethodName {
-  class Range extends Literal::Range, @underscore_method_name {
-    final override Generated::UnderscoreMethodName generated;
+  private class TokenTypes =
+    @setter or @token_class_variable or @token_constant or @token_global_variable or
+        @token_identifier or @token_instance_variable or @token_operator;
 
+  abstract class Range extends Literal::Range, @underscore_method_name {
     Range() {
       exists(Generated::Undef u | u.getChild(_) = generated)
       or
       exists(Generated::Alias a | a.getName() = generated or a.getAlias() = generated)
     }
+  }
+
+  private class TokenMethodName extends MethodName::Range, TokenTypes {
+    final override Generated::UnderscoreMethodName generated;
 
     final override string getValueText() {
-      result = generated.(Generated::Token).getValue() or
-      result = generated.(SymbolLiteral).getValueText() or
+      result = generated.(Generated::Token).getValue()
+      or
       result = generated.(Generated::Setter).getName().getValue() + "="
     }
-
-    final override string toString() {
-      result = getValueText()
-      or
-      not exists(getValueText()) and result = generated.(SymbolLiteral).toString()
-    }
   }
+
+  private class SimpleSymbolMethodName extends MethodName::Range, SymbolLiteral::SimpleSymbolRange,
+    @token_simple_symbol { }
+
+  private class DelimitedSymbolMethodName extends MethodName::Range,
+    SymbolLiteral::DelimitedSymbolRange, @delimited_symbol { }
 }
 
 module StmtSequence {

ql/src/codeql_ruby/ast/internal/Statement.qll

@@ -39,9 +39,9 @@ module AliasStmt {
   class Range extends Stmt::Range, @alias {
     final override Generated::Alias generated;
 
-    final MethodName getNewName() { result = generated.getAlias() }
+    final MethodName getNewName() { result = generated.getName() }
 
-    final MethodName getOldName() { result = generated.getName() }
+    final MethodName getOldName() { result = generated.getAlias() }
 
     final override string toString() { result = "alias ..." }
   }