avoid more useless type assertions (#31239)

Author: ajafff

src/compiler/factory.ts

@@ -1004,10 +1004,10 @@ namespace ts {
             : node;
     }
 
-    export function createPropertyAccess(expression: Expression, name: string | Identifier | undefined) {
+    export function createPropertyAccess(expression: Expression, name: string | Identifier) {
         const node = <PropertyAccessExpression>createSynthesizedNode(SyntaxKind.PropertyAccessExpression);
         node.expression = parenthesizeForAccess(expression);
-        node.name = asName(name)!; // TODO: GH#18217
+        node.name = asName(name);
         setEmitFlags(node, EmitFlags.NoIndentation);
         return node;
     }
@@ -2468,7 +2468,7 @@ namespace ts {
 
     export function createSpreadAssignment(expression: Expression) {
         const node = <SpreadAssignment>createSynthesizedNode(SyntaxKind.SpreadAssignment);
-        node.expression = expression !== undefined ? parenthesizeExpressionForList(expression) : undefined!; // TODO: GH#18217
+        node.expression = parenthesizeExpressionForList(expression);
         return node;
     }
 

src/compiler/parser.ts

@@ -1328,6 +1328,8 @@ namespace ts {
             return node;
         }
 
+        function createMissingNode<T extends Node>(kind: T["kind"], reportAtCurrentPosition: false, diagnosticMessage?: DiagnosticMessage, arg0?: any): T;
+        function createMissingNode<T extends Node>(kind: T["kind"], reportAtCurrentPosition: boolean, diagnosticMessage: DiagnosticMessage, arg0?: any): T;
         function createMissingNode<T extends Node>(kind: T["kind"], reportAtCurrentPosition: boolean, diagnosticMessage: DiagnosticMessage, arg0?: any): T {
             if (reportAtCurrentPosition) {
                 parseErrorAtPosition(scanner.getStartPos(), 0, diagnosticMessage, arg0);
@@ -4290,7 +4292,7 @@ namespace ts {
                     badNode.end = invalidElement.end;
                     badNode.left = result;
                     badNode.right = invalidElement;
-                    badNode.operatorToken = createMissingNode(SyntaxKind.CommaToken, /*reportAtCurrentPosition*/ false, /*diagnosticMessage*/ undefined!); // TODO: GH#18217
+                    badNode.operatorToken = createMissingNode(SyntaxKind.CommaToken, /*reportAtCurrentPosition*/ false);
                     badNode.operatorToken.pos = badNode.operatorToken.end = badNode.right.pos;
                     return <JsxElement><Node>badNode;
                 }

src/compiler/transformers/es2015.ts

@@ -1639,7 +1639,7 @@ namespace ts {
             // arguments are both mapped contiguously to the accessor name.
             const target = getMutableClone(receiver);
             setEmitFlags(target, EmitFlags.NoComments | EmitFlags.NoTrailingSourceMap);
-            setSourceMapRange(target, firstAccessor.name); // TODO: GH#18217
+            setSourceMapRange(target, firstAccessor.name);
 
             const propertyName = createExpressionForPropertyName(visitNode(firstAccessor.name, visitor, isPropertyName));
             setEmitFlags(propertyName, EmitFlags.NoComments | EmitFlags.NoLeadingSourceMap);

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -3856,7 +3856,7 @@ declare namespace ts {
     function updateArrayLiteral(node: ArrayLiteralExpression, elements: ReadonlyArray<Expression>): ArrayLiteralExpression;
     function createObjectLiteral(properties?: ReadonlyArray<ObjectLiteralElementLike>, multiLine?: boolean): ObjectLiteralExpression;
     function updateObjectLiteral(node: ObjectLiteralExpression, properties: ReadonlyArray<ObjectLiteralElementLike>): ObjectLiteralExpression;
-    function createPropertyAccess(expression: Expression, name: string | Identifier | undefined): PropertyAccessExpression;
+    function createPropertyAccess(expression: Expression, name: string | Identifier): PropertyAccessExpression;
     function updatePropertyAccess(node: PropertyAccessExpression, expression: Expression, name: Identifier): PropertyAccessExpression;
     function createElementAccess(expression: Expression, index: number | Expression): ElementAccessExpression;
     function updateElementAccess(node: ElementAccessExpression, expression: Expression, argumentExpression: Expression): ElementAccessExpression;

tests/baselines/reference/api/typescript.d.ts

@@ -3856,7 +3856,7 @@ declare namespace ts {
     function updateArrayLiteral(node: ArrayLiteralExpression, elements: ReadonlyArray<Expression>): ArrayLiteralExpression;
     function createObjectLiteral(properties?: ReadonlyArray<ObjectLiteralElementLike>, multiLine?: boolean): ObjectLiteralExpression;
     function updateObjectLiteral(node: ObjectLiteralExpression, properties: ReadonlyArray<ObjectLiteralElementLike>): ObjectLiteralExpression;
-    function createPropertyAccess(expression: Expression, name: string | Identifier | undefined): PropertyAccessExpression;
+    function createPropertyAccess(expression: Expression, name: string | Identifier): PropertyAccessExpression;
     function updatePropertyAccess(node: PropertyAccessExpression, expression: Expression, name: Identifier): PropertyAccessExpression;
     function createElementAccess(expression: Expression, index: number | Expression): ElementAccessExpression;
     function updateElementAccess(node: ElementAccessExpression, expression: Expression, argumentExpression: Expression): ElementAccessExpression;