Restrict parsing of literals and their expressions a _lot_ more (#17628)

src/compiler/parser.ts

@@ -2061,7 +2061,7 @@ namespace ts {
             return <TemplateMiddle | TemplateTail>fragment;
         }
 
-        function parseLiteralLikeNode(kind: SyntaxKind): LiteralLikeNode {
+        function parseLiteralLikeNode(kind: SyntaxKind): LiteralExpression | LiteralLikeNode {
             const node = <LiteralExpression>createNode(kind);
             const text = scanner.getTokenValue();
             node.text = text;
@@ -2611,11 +2611,31 @@ namespace ts {
             return token() === SyntaxKind.DotToken ? undefined : node;
         }
 
-        function parseLiteralTypeNode(): LiteralTypeNode {
-            const node = <LiteralTypeNode>createNode(SyntaxKind.LiteralType);
-            node.literal = parseSimpleUnaryExpression();
-            finishNode(node);
-            return node;
+        function parseLiteralTypeNode(negative?: boolean): LiteralTypeNode {
+            const node = createNode(SyntaxKind.LiteralType) as LiteralTypeNode;
+            let unaryMinusExpression: PrefixUnaryExpression;
+            if (negative) {
+                unaryMinusExpression = createNode(SyntaxKind.PrefixUnaryExpression) as PrefixUnaryExpression;
+                unaryMinusExpression.operator = SyntaxKind.MinusToken;
+                nextToken();
+            }
+            let expression: UnaryExpression;
+            switch (token()) {
+                case SyntaxKind.StringLiteral:
+                case SyntaxKind.NumericLiteral:
+                    expression = parseLiteralLikeNode(token()) as LiteralExpression;
+                    break;
+                case SyntaxKind.TrueKeyword:
+                case SyntaxKind.FalseKeyword:
+                    expression = parseTokenNode();
+            }
+            if (negative) {
+                unaryMinusExpression.operand = expression;
+                finishNode(unaryMinusExpression);
+                expression = unaryMinusExpression;
+            }
+            node.literal = expression;
+            return finishNode(node);
         }
 
         function nextTokenIsNumericLiteral() {
@@ -2650,7 +2670,7 @@ namespace ts {
                 case SyntaxKind.FalseKeyword:
                     return parseLiteralTypeNode();
                 case SyntaxKind.MinusToken:
-                    return lookAhead(nextTokenIsNumericLiteral) ? parseLiteralTypeNode() : parseTypeReference();
+                    return lookAhead(nextTokenIsNumericLiteral) ? parseLiteralTypeNode(/*negative*/ true) : parseTypeReference();
                 case SyntaxKind.VoidKeyword:
                 case SyntaxKind.NullKeyword:
                     return parseTokenNode<TypeNode>();

tests/baselines/reference/expressionTypeNodeShouldError.errors.txt

@@ -0,0 +1,90 @@
+tests/cases/compiler/base.d.ts(1,23): error TS1005: ',' expected.
+tests/cases/compiler/base.d.ts(1,34): error TS1005: '=' expected.
+tests/cases/compiler/boolean.ts(7,23): error TS1005: ',' expected.
+tests/cases/compiler/boolean.ts(7,24): error TS1134: Variable declaration expected.
+tests/cases/compiler/boolean.ts(11,16): error TS2304: Cannot find name 'document'.
+tests/cases/compiler/boolean.ts(12,22): error TS1005: ';' expected.
+tests/cases/compiler/number.ts(7,26): error TS1005: ',' expected.
+tests/cases/compiler/number.ts(7,27): error TS1134: Variable declaration expected.
+tests/cases/compiler/number.ts(11,16): error TS2304: Cannot find name 'document'.
+tests/cases/compiler/number.ts(12,20): error TS1005: ';' expected.
+tests/cases/compiler/string.ts(7,20): error TS1005: ',' expected.
+tests/cases/compiler/string.ts(7,21): error TS1134: Variable declaration expected.
+tests/cases/compiler/string.ts(11,15): error TS2304: Cannot find name 'document'.
+tests/cases/compiler/string.ts(12,19): error TS1005: ';' expected.
+
+
+==== tests/cases/compiler/base.d.ts (2 errors) ====
+    declare const x: "foo".charCodeAt(0);
+                          ~
+!!! error TS1005: ',' expected.
+                                     ~
+!!! error TS1005: '=' expected.
+    
+==== tests/cases/compiler/string.ts (4 errors) ====
+    interface String {
+        typeof<T>(x: T): T;
+    }
+    
+    class C {
+        foo() {
+            const x: "".typeof(this.foo);
+                       ~
+!!! error TS1005: ',' expected.
+                        ~~~~~~
+!!! error TS1134: Variable declaration expected.
+        }
+    }
+    
+    const nodes = document.getElementsByTagName("li");
+                  ~~~~~~~~
+!!! error TS2304: Cannot find name 'document'.
+    type ItemType = "".typeof(nodes.item(0));
+                      ~
+!!! error TS1005: ';' expected.
+    
+==== tests/cases/compiler/number.ts (4 errors) ====
+    interface Number {
+        typeof<T>(x: T): T;
+    }
+    
+    class C2 {
+        foo() {
+            const x: 3.141592.typeof(this.foo);
+                             ~
+!!! error TS1005: ',' expected.
+                              ~~~~~~
+!!! error TS1134: Variable declaration expected.
+        }
+    }
+    
+    const nodes2 = document.getElementsByTagName("li");
+                   ~~~~~~~~
+!!! error TS2304: Cannot find name 'document'.
+    type ItemType2 = 4..typeof(nodes.item(0));
+                       ~
+!!! error TS1005: ';' expected.
+    
+==== tests/cases/compiler/boolean.ts (4 errors) ====
+    interface Boolean {
+        typeof<T>(x: T): T;
+    }
+    
+    class C3 {
+        foo() {
+            const x: false.typeof(this.foo);
+                          ~
+!!! error TS1005: ',' expected.
+                           ~~~~~~
+!!! error TS1134: Variable declaration expected.
+        }
+    }
+    
+    const nodes3 = document.getElementsByTagName("li");
+                   ~~~~~~~~
+!!! error TS2304: Cannot find name 'document'.
+    type ItemType3 = true.typeof(nodes.item(0));
+                         ~
+!!! error TS1005: ';' expected.
+    
+    

tests/baselines/reference/expressionTypeNodeShouldError.js

@@ -0,0 +1,85 @@
+//// [tests/cases/compiler/expressionTypeNodeShouldError.ts] ////
+
+//// [base.d.ts]
+declare const x: "foo".charCodeAt(0);
+
+//// [string.ts]
+interface String {
+    typeof<T>(x: T): T;
+}
+
+class C {
+    foo() {
+        const x: "".typeof(this.foo);
+    }
+}
+
+const nodes = document.getElementsByTagName("li");
+type ItemType = "".typeof(nodes.item(0));
+
+//// [number.ts]
+interface Number {
+    typeof<T>(x: T): T;
+}
+
+class C2 {
+    foo() {
+        const x: 3.141592.typeof(this.foo);
+    }
+}
+
+const nodes2 = document.getElementsByTagName("li");
+type ItemType2 = 4..typeof(nodes.item(0));
+
+//// [boolean.ts]
+interface Boolean {
+    typeof<T>(x: T): T;
+}
+
+class C3 {
+    foo() {
+        const x: false.typeof(this.foo);
+    }
+}
+
+const nodes3 = document.getElementsByTagName("li");
+type ItemType3 = true.typeof(nodes.item(0));
+
+
+
+//// [string.js]
+var C = (function () {
+    function C() {
+    }
+    C.prototype.foo = function () {
+        var x;
+        typeof (this.foo);
+    };
+    return C;
+}());
+var nodes = document.getElementsByTagName("li");
+typeof (nodes.item(0));
+//// [number.js]
+var C2 = (function () {
+    function C2() {
+    }
+    C2.prototype.foo = function () {
+        var x;
+        typeof (this.foo);
+    };
+    return C2;
+}());
+var nodes2 = document.getElementsByTagName("li");
+typeof (nodes.item(0));
+//// [boolean.js]
+var C3 = (function () {
+    function C3() {
+    }
+    C3.prototype.foo = function () {
+        var x;
+        typeof (this.foo);
+    };
+    return C3;
+}());
+var nodes3 = document.getElementsByTagName("li");
+typeof (nodes.item(0));

tests/cases/compiler/expressionTypeNodeShouldError.ts

@@ -0,0 +1,45 @@
+// @Filename: base.d.ts
+declare const x: "foo".charCodeAt(0);
+
+// @filename: string.ts
+interface String {
+    typeof<T>(x: T): T;
+}
+
+class C {
+    foo() {
+        const x: "".typeof(this.foo);
+    }
+}
+
+const nodes = document.getElementsByTagName("li");
+type ItemType = "".typeof(nodes.item(0));
+
+// @filename: number.ts
+interface Number {
+    typeof<T>(x: T): T;
+}
+
+class C2 {
+    foo() {
+        const x: 3.141592.typeof(this.foo);
+    }
+}
+
+const nodes2 = document.getElementsByTagName("li");
+type ItemType2 = 4..typeof(nodes.item(0));
+
+// @filename: boolean.ts
+interface Boolean {
+    typeof<T>(x: T): T;
+}
+
+class C3 {
+    foo() {
+        const x: false.typeof(this.foo);
+    }
+}
+
+const nodes3 = document.getElementsByTagName("li");
+type ItemType3 = true.typeof(nodes.item(0));
+