Fix many no-object-literal-type-assertion lint errors (#17278)

* Fix many no-object-literal-type-assertion lint errors

* Simple fixes

* Use a union for FlowNode

* PR feedback and remove remaining `id()` uses

* Use a union for CodeBlock

* Discriminate CodeBlock by CodeBlockKind

Author: Andy

src/compiler/binder.ts

@@ -806,43 +806,26 @@ namespace ts {
                 return antecedent;
             }
             setFlowNodeReferenced(antecedent);
-            return <FlowCondition>{
-                flags,
-                expression,
-                antecedent
-            };
+            return { flags, expression, antecedent };
         }
 
         function createFlowSwitchClause(antecedent: FlowNode, switchStatement: SwitchStatement, clauseStart: number, clauseEnd: number): FlowNode {
             if (!isNarrowingExpression(switchStatement.expression)) {
                 return antecedent;
             }
             setFlowNodeReferenced(antecedent);
-            return <FlowSwitchClause>{
-                flags: FlowFlags.SwitchClause,
-                switchStatement,
-                clauseStart,
-                clauseEnd,
-                antecedent
-            };
+            return { flags: FlowFlags.SwitchClause, switchStatement, clauseStart, clauseEnd, antecedent };
         }
 
         function createFlowAssignment(antecedent: FlowNode, node: Expression | VariableDeclaration | BindingElement): FlowNode {
             setFlowNodeReferenced(antecedent);
-            return <FlowAssignment>{
-                flags: FlowFlags.Assignment,
-                antecedent,
-                node
-            };
+            return { flags: FlowFlags.Assignment, antecedent, node };
         }
 
         function createFlowArrayMutation(antecedent: FlowNode, node: CallExpression | BinaryExpression): FlowNode {
             setFlowNodeReferenced(antecedent);
-            return <FlowArrayMutation>{
-                flags: FlowFlags.ArrayMutation,
-                antecedent,
-                node
-            };
+            const res: FlowArrayMutation = { flags: FlowFlags.ArrayMutation, antecedent, node };
+            return res;
         }
 
         function finishFlowLabel(flow: FlowLabel): FlowNode {

src/compiler/checker.ts

@@ -2172,7 +2172,7 @@ namespace ts {
                     if (accessibleSymbolChain) {
                         const hasAccessibleDeclarations = hasVisibleDeclarations(accessibleSymbolChain[0], shouldComputeAliasesToMakeVisible);
                         if (!hasAccessibleDeclarations) {
-                            return <SymbolAccessibilityResult>{
+                            return {
                                 accessibility: SymbolAccessibility.NotAccessible,
                                 errorSymbolName: symbolToString(initialSymbol, enclosingDeclaration, meaning),
                                 errorModuleName: symbol !== initialSymbol ? symbolToString(symbol, enclosingDeclaration, SymbolFlags.Namespace) : undefined,
@@ -2294,7 +2294,7 @@ namespace ts {
             const symbol = resolveName(enclosingDeclaration, firstIdentifier.escapedText, meaning, /*nodeNotFoundErrorMessage*/ undefined, /*nameArg*/ undefined);
 
             // Verify if the symbol is accessible
-            return (symbol && hasVisibleDeclarations(symbol, /*shouldComputeAliasToMakeVisible*/ true)) || <SymbolVisibilityResult>{
+            return (symbol && hasVisibleDeclarations(symbol, /*shouldComputeAliasToMakeVisible*/ true)) || {
                 accessibility: SymbolAccessibility.NotAccessible,
                 errorSymbolName: getTextOfNode(firstIdentifier),
                 errorNode: firstIdentifier
@@ -6300,7 +6300,7 @@ namespace ts {
                 return {
                     kind: TypePredicateKind.This,
                     type: getTypeFromTypeNode(node.type)
-                } as ThisTypePredicate;
+                };
             }
         }
 
@@ -8109,13 +8109,13 @@ namespace ts {
                     parameterName: predicate.parameterName,
                     parameterIndex: predicate.parameterIndex,
                     type: instantiateType(predicate.type, mapper)
-                } as IdentifierTypePredicate;
+                };
             }
             else {
                 return {
                     kind: TypePredicateKind.This,
                     type: instantiateType(predicate.type, mapper)
-                } as ThisTypePredicate;
+                };
             }
         }
 

src/compiler/emitter.ts

@@ -1195,7 +1195,9 @@ namespace ts {
             if (!(getEmitFlags(node) & EmitFlags.NoIndentation)) {
                 const dotRangeStart = node.expression.end;
                 const dotRangeEnd = skipTrivia(currentSourceFile.text, node.expression.end) + 1;
-                const dotToken = <Node>{ kind: SyntaxKind.DotToken, pos: dotRangeStart, end: dotRangeEnd };
+                const dotToken = createToken(SyntaxKind.DotToken);
+                dotToken.pos = dotRangeStart;
+                dotToken.end = dotRangeEnd;
                 indentBeforeDot = needsIndentation(node, node.expression, dotToken);
                 indentAfterDot = needsIndentation(node, dotToken, node.name);
             }

src/compiler/factory.ts

@@ -2586,7 +2586,7 @@ namespace ts {
     }
 
     export function addSyntheticLeadingComment<T extends Node>(node: T, kind: SyntaxKind.SingleLineCommentTrivia | SyntaxKind.MultiLineCommentTrivia, text: string, hasTrailingNewLine?: boolean) {
-        return setSyntheticLeadingComments(node, append(getSyntheticLeadingComments(node), <SynthesizedComment>{ kind, pos: -1, end: -1, hasTrailingNewLine, text }));
+        return setSyntheticLeadingComments(node, append<SynthesizedComment>(getSyntheticLeadingComments(node), { kind, pos: -1, end: -1, hasTrailingNewLine, text }));
     }
 
     export function getSyntheticTrailingComments(node: Node): SynthesizedComment[] | undefined {
@@ -2600,7 +2600,7 @@ namespace ts {
     }
 
     export function addSyntheticTrailingComment<T extends Node>(node: T, kind: SyntaxKind.SingleLineCommentTrivia | SyntaxKind.MultiLineCommentTrivia, text: string, hasTrailingNewLine?: boolean) {
-        return setSyntheticTrailingComments(node, append(getSyntheticTrailingComments(node), <SynthesizedComment>{ kind, pos: -1, end: -1, hasTrailingNewLine, text }));
+        return setSyntheticTrailingComments(node, append<SynthesizedComment>(getSyntheticTrailingComments(node), { kind, pos: -1, end: -1, hasTrailingNewLine, text }));
     }
 
     /**

src/compiler/parser.ts

@@ -6169,7 +6169,7 @@ namespace ts {
 
             export function parseIsolatedJSDocComment(content: string, start: number, length: number): { jsDoc: JSDoc, diagnostics: Diagnostic[] } | undefined {
                 initializeState(content, ScriptTarget.Latest, /*_syntaxCursor:*/ undefined, ScriptKind.JS);
-                sourceFile = <SourceFile>{ languageVariant: LanguageVariant.Standard, text: content };
+                sourceFile = <SourceFile>{ languageVariant: LanguageVariant.Standard, text: content }; // tslint:disable-line no-object-literal-type-assertion
                 const jsDoc = parseJSDocCommentWorker(start, length);
                 const diagnostics = parseDiagnostics;
                 clearState();

src/compiler/transformers/generators.ts

@@ -164,12 +164,11 @@ namespace ts {
     }
 
     // A generated code block
-    interface CodeBlock {
-        kind: CodeBlockKind;
-    }
+    type CodeBlock = | ExceptionBlock | LabeledBlock | SwitchBlock | LoopBlock | WithBlock;
 
     // a generated exception block, used for 'try' statements
-    interface ExceptionBlock extends CodeBlock {
+    interface ExceptionBlock {
+        kind: CodeBlockKind.Exception;
         state: ExceptionBlockState;
         startLabel: Label;
         catchVariable?: Identifier;
@@ -179,27 +178,31 @@ namespace ts {
     }
 
     // A generated code that tracks the target for 'break' statements in a LabeledStatement.
-    interface LabeledBlock extends CodeBlock {
+    interface LabeledBlock {
+        kind: CodeBlockKind.Labeled;
         labelText: string;
         isScript: boolean;
         breakLabel: Label;
     }
 
     // a generated block that tracks the target for 'break' statements in a 'switch' statement
-    interface SwitchBlock extends CodeBlock {
+    interface SwitchBlock {
+        kind: CodeBlockKind.Switch;
         isScript: boolean;
         breakLabel: Label;
     }
 
     // a generated block that tracks the targets for 'break' and 'continue' statements, used for iteration statements
-    interface LoopBlock extends CodeBlock {
+    interface LoopBlock {
+        kind: CodeBlockKind.Loop;
         continueLabel: Label;
         isScript: boolean;
         breakLabel: Label;
     }
 
     // a generated block associated with a 'with' statement
-    interface WithBlock extends CodeBlock {
+    interface WithBlock {
+        kind: CodeBlockKind.With;
         expression: Identifier;
         startLabel: Label;
         endLabel: Label;
@@ -2070,7 +2073,7 @@ namespace ts {
             const startLabel = defineLabel();
             const endLabel = defineLabel();
             markLabel(startLabel);
-            beginBlock(<WithBlock>{
+            beginBlock({
                 kind: CodeBlockKind.With,
                 expression,
                 startLabel,
@@ -2087,18 +2090,14 @@ namespace ts {
             markLabel(block.endLabel);
         }
 
-        function isWithBlock(block: CodeBlock): block is WithBlock {
-            return block.kind === CodeBlockKind.With;
-        }
-
         /**
          * Begins a code block for a generated `try` statement.
          */
         function beginExceptionBlock(): Label {
             const startLabel = defineLabel();
             const endLabel = defineLabel();
             markLabel(startLabel);
-            beginBlock(<ExceptionBlock>{
+            beginBlock({
                 kind: CodeBlockKind.Exception,
                 state: ExceptionBlockState.Try,
                 startLabel,
@@ -2188,18 +2187,14 @@ namespace ts {
             exception.state = ExceptionBlockState.Done;
         }
 
-        function isExceptionBlock(block: CodeBlock): block is ExceptionBlock {
-            return block.kind === CodeBlockKind.Exception;
-        }
-
         /**
          * Begins a code block that supports `break` or `continue` statements that are defined in
          * the source tree and not from generated code.
          *
          * @param labelText Names from containing labeled statements.
          */
         function beginScriptLoopBlock(): void {
-            beginBlock(<LoopBlock>{
+            beginBlock({
                 kind: CodeBlockKind.Loop,
                 isScript: true,
                 breakLabel: -1,
@@ -2217,7 +2212,7 @@ namespace ts {
          */
         function beginLoopBlock(continueLabel: Label): Label {
             const breakLabel = defineLabel();
-            beginBlock(<LoopBlock>{
+            beginBlock({
                 kind: CodeBlockKind.Loop,
                 isScript: false,
                 breakLabel,
@@ -2245,7 +2240,7 @@ namespace ts {
          *
          */
         function beginScriptSwitchBlock(): void {
-            beginBlock(<SwitchBlock>{
+            beginBlock({
                 kind: CodeBlockKind.Switch,
                 isScript: true,
                 breakLabel: -1
@@ -2259,7 +2254,7 @@ namespace ts {
          */
         function beginSwitchBlock(): Label {
             const breakLabel = defineLabel();
-            beginBlock(<SwitchBlock>{
+            beginBlock({
                 kind: CodeBlockKind.Switch,
                 isScript: false,
                 breakLabel,
@@ -2280,7 +2275,7 @@ namespace ts {
         }
 
         function beginScriptLabeledBlock(labelText: string) {
-            beginBlock(<LabeledBlock>{
+            beginBlock({
                 kind: CodeBlockKind.Labeled,
                 isScript: true,
                 labelText,
@@ -2290,7 +2285,7 @@ namespace ts {
 
         function beginLabeledBlock(labelText: string) {
             const breakLabel = defineLabel();
-            beginBlock(<LabeledBlock>{
+            beginBlock({
                 kind: CodeBlockKind.Labeled,
                 isScript: false,
                 labelText,
@@ -2878,34 +2873,37 @@ namespace ts {
                 for (; blockIndex < blockActions.length && blockOffsets[blockIndex] <= operationIndex; blockIndex++) {
                     const block = blocks[blockIndex];
                     const blockAction = blockActions[blockIndex];
-                    if (isExceptionBlock(block)) {
-                        if (blockAction === BlockAction.Open) {
-                            if (!exceptionBlockStack) {
-                                exceptionBlockStack = [];
-                            }
+                    switch (block.kind) {
+                        case CodeBlockKind.Exception:
+                            if (blockAction === BlockAction.Open) {
+                                if (!exceptionBlockStack) {
+                                    exceptionBlockStack = [];
+                                }
 
-                            if (!statements) {
-                                statements = [];
-                            }
+                                if (!statements) {
+                                    statements = [];
+                                }
 
-                            exceptionBlockStack.push(currentExceptionBlock);
-                            currentExceptionBlock = block;
-                        }
-                        else if (blockAction === BlockAction.Close) {
-                            currentExceptionBlock = exceptionBlockStack.pop();
-                        }
-                    }
-                    else if (isWithBlock(block)) {
-                        if (blockAction === BlockAction.Open) {
-                            if (!withBlockStack) {
-                                withBlockStack = [];
+                                exceptionBlockStack.push(currentExceptionBlock);
+                                currentExceptionBlock = block;
                             }
+                            else if (blockAction === BlockAction.Close) {
+                                currentExceptionBlock = exceptionBlockStack.pop();
+                            }
+                            break;
+                        case CodeBlockKind.With:
+                            if (blockAction === BlockAction.Open) {
+                                if (!withBlockStack) {
+                                    withBlockStack = [];
+                                }
 
-                            withBlockStack.push(block);
-                        }
-                        else if (blockAction === BlockAction.Close) {
-                            withBlockStack.pop();
-                        }
+                                withBlockStack.push(block);
+                            }
+                            else if (blockAction === BlockAction.Close) {
+                                withBlockStack.pop();
+                            }
+                            break;
+                        // default: do nothing
                     }
                 }
             }