Remove unnecessary type assertions

src/compiler/binder.ts

@@ -2618,7 +2618,7 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
         if (inStrictMode && isLeftHandSideExpression(node.left) && isAssignmentOperator(node.operatorToken.kind)) {
             // ECMA 262 (Annex C) The identifier eval or arguments may not appear as the LeftHandSideExpression of an
             // Assignment operator(11.13) or of a PostfixExpression(11.3)
-            checkStrictModeEvalOrArguments(node, node.left as Identifier);
+            checkStrictModeEvalOrArguments(node, node.left);
         }
     }
 
@@ -2713,15 +2713,15 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
         // Assignment operator(11.13) or of a PostfixExpression(11.3) or as the UnaryExpression
         // operated upon by a Prefix Increment(11.4.4) or a Prefix Decrement(11.4.5) operator.
         if (inStrictMode) {
-            checkStrictModeEvalOrArguments(node, node.operand as Identifier);
+            checkStrictModeEvalOrArguments(node, node.operand);
         }
     }
 
     function checkStrictModePrefixUnaryExpression(node: PrefixUnaryExpression) {
         // Grammar checking
         if (inStrictMode) {
             if (node.operator === SyntaxKind.PlusPlusToken || node.operator === SyntaxKind.MinusMinusToken) {
-                checkStrictModeEvalOrArguments(node, node.operand as Identifier);
+                checkStrictModeEvalOrArguments(node, node.operand);
             }
         }
     }

src/compiler/emitter.ts

@@ -62,7 +62,6 @@ import {
     DeleteExpression,
     directorySeparator,
     DoStatement,
-    DotToken,
     ElementAccessExpression,
     emitDetachedComments,
     EmitFileNames,
@@ -2620,7 +2619,7 @@ export function createPrinter(printerOptions: PrinterOptions = {}, handlers: Pri
 
     function emitPropertyAccessExpression(node: PropertyAccessExpression) {
         emitExpression(node.expression, parenthesizer.parenthesizeLeftSideOfAccess);
-        const token = node.questionDotToken || setTextRangePosEnd(factory.createToken(SyntaxKind.DotToken) as DotToken, node.expression.end, node.name.pos);
+        const token = node.questionDotToken || setTextRangePosEnd(factory.createToken(SyntaxKind.DotToken), node.expression.end, node.name.pos);
         const linesBeforeDot = getLinesBetweenNodes(node, node.expression, token);
         const linesAfterDot = getLinesBetweenNodes(node, token, node.name);
 
@@ -4433,13 +4432,13 @@ export function createPrinter(printerOptions: PrinterOptions = {}, handlers: Pri
         if (modifiers?.length) {
             if (every(modifiers, isModifier)) {
                 // if all modifier-likes are `Modifier`, simply emit the array as modifiers.
-                return emitModifierList(node, modifiers as NodeArray<Modifier>);
+                return emitModifierList(node, modifiers);
             }
 
             if (every(modifiers, isDecorator)) {
                 if (allowDecorators) {
                     // if all modifier-likes are `Decorator`, simply emit the array as decorators.
-                    return emitDecoratorList(node, modifiers as NodeArray<Decorator>);
+                    return emitDecoratorList(node, modifiers);
                 }
                 return node.pos;
             }

src/compiler/parser.ts

@@ -10109,7 +10109,7 @@ namespace IncrementalParser {
                 Debug.assert(text === newText.substring(node.pos, node.end));
             }
 
-            forEachChild(node, visitNode as (node: Node) => void, visitArray as (nodes: NodeArray<Node>) => void);
+            forEachChild(node, visitNode, visitArray);
             if (hasJSDocNodes(node)) {
                 for (const jsDocComment of node.jsDoc!) {
                     visitNode(jsDocComment);
@@ -10262,7 +10262,7 @@ namespace IncrementalParser {
 
                 // Adjust the pos or end (or both) of the intersecting element accordingly.
                 adjustIntersectingElement(child, changeStart, changeRangeOldEnd, changeRangeNewEnd, delta);
-                forEachChild(child, visitNode as (node: Node) => void, visitArray as (nodes: NodeArray<Node>) => void);
+                forEachChild(child, visitNode, visitArray);
                 if (hasJSDocNodes(child)) {
                     for (const jsDocComment of child.jsDoc!) {
                         visitNode(jsDocComment);

src/compiler/symbolWalker.ts

@@ -101,7 +101,7 @@ export function createGetSymbolWalker(
                 }
             }
             if (type.flags & TypeFlags.TypeParameter) {
-                visitTypeParameter(type as TypeParameter);
+                visitTypeParameter(type);
             }
             if (type.flags & TypeFlags.UnionOrIntersection) {
                 visitUnionOrIntersectionType(type as UnionOrIntersectionType);

src/compiler/transformers/es2018.ts

@@ -1373,7 +1373,7 @@ export function transformES2018(context: TransformationContext): (x: SourceFile
         // Disable substitution in the generated super accessor itself.
         else if (enabledSubstitutions && substitutedSuperAccessors[getNodeId(node)]) {
             const savedEnclosingSuperContainerFlags = enclosingSuperContainerFlags;
-            enclosingSuperContainerFlags = 0 as NodeCheckFlags;
+            enclosingSuperContainerFlags = 0;
             previousOnEmitNode(hint, node, emitCallback);
             enclosingSuperContainerFlags = savedEnclosingSuperContainerFlags;
             return;

src/compiler/transformers/ts.ts

@@ -2243,7 +2243,7 @@ export function transformTypeScript(context: TransformationContext): Transformer
     function getInnerMostModuleDeclarationFromDottedModule(moduleDeclaration: ModuleDeclaration): ModuleDeclaration | undefined {
         if (moduleDeclaration.body!.kind === SyntaxKind.ModuleDeclaration) {
             const recursiveInnerModule = getInnerMostModuleDeclarationFromDottedModule(moduleDeclaration.body as ModuleDeclaration);
-            return recursiveInnerModule || moduleDeclaration.body as ModuleDeclaration;
+            return recursiveInnerModule || moduleDeclaration.body;
         }
     }
 

src/compiler/tsbuildPublic.ts

@@ -432,7 +432,7 @@ function createSolutionBuilderState<T extends BuilderProgram>(watch: boolean, ho
 
     // State of the solution
     const baseCompilerOptions = getCompilerOptionsOfBuildOptions(options);
-    const compilerHost = createCompilerHostFromProgramHost(host, () => state.projectCompilerOptions) as CompilerHost & ReadBuildProgramHost;
+    const compilerHost = createCompilerHostFromProgramHost(host, () => state.projectCompilerOptions);
     setGetSourceFileAsHashVersioned(compilerHost);
     compilerHost.getParsedCommandLine = fileName => parseConfigFile(state, fileName as ResolvedConfigFileName, toResolvedConfigFilePath(state, fileName as ResolvedConfigFileName));
     compilerHost.resolveModuleNameLiterals = maybeBind(host, host.resolveModuleNameLiterals);

src/compiler/utilities.ts

@@ -12269,7 +12269,7 @@ export function getSynthesizedDeepCloneWithReplacements<T extends Node>(
         setOriginalNode(clone, node);
     }
     else {
-        clone = getSynthesizedDeepCloneWorker(node as NonNullable<T>, replaceNode);
+        clone = getSynthesizedDeepCloneWorker(node, replaceNode);
     }
 
     if (clone && !includeTrivia) suppressLeadingAndTrailingTrivia(clone);

src/compiler/utilitiesPublic.ts

@@ -927,7 +927,7 @@ function getDeclarationIdentifier(node: Declaration | Expression): Identifier |
 
 /** @internal */
 export function nodeHasName(statement: Node, name: Identifier): boolean {
-    if (isNamedDeclaration(statement) && isIdentifier(statement.name) && idText(statement.name as Identifier) === idText(name)) {
+    if (isNamedDeclaration(statement) && isIdentifier(statement.name) && idText(statement.name) === idText(name)) {
         return true;
     }
     if (isVariableStatement(statement) && some(statement.declarationList.declarations, d => nodeHasName(d, name))) {

src/server/editorServices.ts

@@ -2063,7 +2063,7 @@ export class ProjectService {
             if (this.openFiles.has(fileOrDirectoryPath)) {
                 const info = Debug.checkDefined(this.getScriptInfoForPath(fileOrDirectoryPath));
                 if (info.isAttached(project)) {
-                    const loadLevelToSet = Math.max(updateLevel, project.openFileWatchTriggered.get(fileOrDirectoryPath) || ProgramUpdateLevel.Update) as ProgramUpdateLevel;
+                    const loadLevelToSet = Math.max(updateLevel, project.openFileWatchTriggered.get(fileOrDirectoryPath) || ProgramUpdateLevel.Update);
                     project.openFileWatchTriggered.set(fileOrDirectoryPath, loadLevelToSet);
                 }
                 else {

src/server/project.ts

@@ -1753,7 +1753,7 @@ export abstract class Project implements LanguageServiceHost, ModuleResolutionHo
             this.moduleSpecifierCache.clear();
         }
 
-        const oldExternalFiles = this.externalFiles || emptyArray as SortedReadonlyArray<string>;
+        const oldExternalFiles = this.externalFiles || emptyArray;
         this.externalFiles = this.getExternalFiles();
         enumerateInsertsAndDeletes<string, string>(
             this.externalFiles,

src/server/session.ts

@@ -829,7 +829,7 @@ function getPerProjectReferences<TResult>(
                     symlinkedProjectsMap.forEach((symlinkedProjects, symlinkedPath) => {
                         for (const symlinkedProject of symlinkedProjects) {
                             if (!symlinkedProject.isOrphan() && !resultsMap.has(symlinkedProject)) { // Optimization: don't enqueue if will be discarded
-                                queue.enqueue({ project: symlinkedProject, location: { fileName: symlinkedPath as string, pos: originalLocation.pos } });
+                                queue.enqueue({ project: symlinkedProject, location: { fileName: symlinkedPath, pos: originalLocation.pos } });
                             }
                         }
                     });

src/server/utilitiesPublic.ts

@@ -44,7 +44,7 @@ export enum Msg {
 export function createInstallTypingsRequest(project: Project, typeAcquisition: TypeAcquisition, unresolvedImports: SortedReadonlyArray<string>, cachePath?: string): DiscoverTypings {
     return {
         projectName: project.getProjectName(),
-        fileNames: project.getFileNames(/*excludeFilesFromExternalLibraries*/ true, /*excludeConfigFiles*/ true).concat(project.getExcludedFiles() as NormalizedPath[]),
+        fileNames: project.getFileNames(/*excludeFilesFromExternalLibraries*/ true, /*excludeConfigFiles*/ true).concat(project.getExcludedFiles()),
         compilerOptions: project.getCompilationSettings(),
         typeAcquisition,
         unresolvedImports,

src/services/classifier.ts

@@ -344,7 +344,7 @@ function convertClassificationsToResult(classifications: Classifications, text:
     for (let i = 0; i < dense.length; i += 3) {
         const start = dense[i];
         const length = dense[i + 1];
-        const type = dense[i + 2] as ClassificationType;
+        const type = dense[i + 2];
 
         // Make a whitespace entry between the last item and this one.
         if (lastEnd >= 0) {

src/services/codefixes/fixUnreferenceableDecoratorMetadata.ts

@@ -17,7 +17,6 @@ import {
     isImportClause,
     isImportEqualsDeclaration,
     isImportSpecifier,
-    Node,
     or,
     Program,
     refactor,
@@ -57,7 +56,7 @@ function getImportDeclaration(sourceFile: SourceFile, program: Program, start: n
 
     const checker = program.getTypeChecker();
     const symbol = checker.getSymbolAtLocation(identifier);
-    return find(symbol?.declarations || emptyArray, or(isImportClause, isImportSpecifier, isImportEqualsDeclaration) as (n: Node) => n is ImportClause | ImportSpecifier | ImportEqualsDeclaration);
+    return find(symbol?.declarations || emptyArray, or(isImportClause, isImportSpecifier, isImportEqualsDeclaration));
 }
 
 // Converts the import declaration of the offending import to a type-only import,

src/services/codefixes/generateAccessors.ts

@@ -197,7 +197,7 @@ export function getAccessorConvertiblePropertyAtPosition(file: SourceFile, progr
         isReadonly: hasEffectiveReadonlyModifier(declaration),
         type: getDeclarationType(declaration, program),
         container: declaration.kind === SyntaxKind.Parameter ? declaration.parent.parent : declaration.parent,
-        originalName: (declaration.name as AcceptedNameType).text,
+        originalName: declaration.name.text,
         declaration,
         fieldName,
         accessorName,

src/services/completions.ts

@@ -5714,7 +5714,7 @@ function tryGetObjectTypeDeclarationCompletionContainer(sourceFile: SourceFile,
         // class C { blah \n constructor/**/ }
         || (isIdentifier(contextToken) && isPropertyDeclaration(contextToken.parent) && isClassLike(location))
     ) {
-        return findAncestor(contextToken, isClassLike) as ObjectTypeDeclaration;
+        return findAncestor(contextToken, isClassLike);
     }
 
     switch (contextToken.kind) {

src/services/findAllReferences.ts

@@ -447,7 +447,7 @@ export function getContextNode(node: NamedDeclaration | BinaryExpression | ForIn
         case SyntaxKind.ShorthandPropertyAssignment:
             return isArrayLiteralOrObjectLiteralDestructuringPattern(node.parent) ?
                 getContextNode(
-                    findAncestor(node.parent, node => isBinaryExpression(node) || isForInOrOfStatement(node)) as BinaryExpression | ForInOrOfStatement,
+                    findAncestor(node.parent, node => isBinaryExpression(node) || isForInOrOfStatement(node)),
                 ) :
                 node;
         case SyntaxKind.SwitchStatement:

src/services/getEditsForFileRename.ts

@@ -31,7 +31,6 @@ import {
     LanguageServiceHost,
     last,
     mapDefined,
-    ModuleResolutionHost,
     moduleSpecifiers,
     normalizePath,
     pathIsRelative,
@@ -207,7 +206,7 @@ function updateImports(
             const toImport = oldFromNew !== undefined
                 // If we're at the new location (file was already renamed), need to redo module resolution starting from the old location.
                 // TODO:GH#18217
-                ? getSourceFileToImportFromResolved(importLiteral, resolveModuleName(importLiteral.text, oldImportFromPath, program.getCompilerOptions(), host as ModuleResolutionHost), oldToNew, allFiles)
+                ? getSourceFileToImportFromResolved(importLiteral, resolveModuleName(importLiteral.text, oldImportFromPath, program.getCompilerOptions(), host), oldToNew, allFiles)
                 : getSourceFileToImport(importedModuleSymbol, importLiteral, sourceFile, program, host, oldToNew);
 
             // Need an update if the imported file moved, or the importing file moved and was using a relative path.

src/services/services.ts

@@ -2631,7 +2631,7 @@ export function createLanguageService(
         [SyntaxKind.OpenBracketToken]: SyntaxKind.CloseBracketToken,
         [SyntaxKind.GreaterThanToken]: SyntaxKind.LessThanToken,
     }));
-    braceMatching.forEach((value, key) => braceMatching.set(value.toString(), Number(key) as SyntaxKind));
+    braceMatching.forEach((value, key) => braceMatching.set(value.toString(), Number(key)));
 
     function getBraceMatchingAtPosition(fileName: string, position: number): TextSpan[] {
         const sourceFile = syntaxTreeCache.getCurrentSourceFile(fileName);

src/services/stringCompletions.ts

@@ -810,7 +810,7 @@ function getCompletionEntriesForDirectoryFragment(
         // check for a version redirect
         const packageJsonPath = findPackageJson(baseDirectory, host);
         if (packageJsonPath) {
-            const packageJson = readJson(packageJsonPath, host as { readFile: (filename: string) => string | undefined; });
+            const packageJson = readJson(packageJsonPath, host);
             const typesVersions = (packageJson as any).typesVersions;
             if (typeof typesVersions === "object") {
                 const versionPaths = getPackageJsonTypesVersionsPaths(typesVersions)?.paths;
@@ -1385,7 +1385,7 @@ function enumerateNodeModulesVisibleToScript(host: LanguageServiceHost, scriptPa
 
     const result: string[] = [];
     for (const packageJson of findPackageJsons(scriptPath, host)) {
-        const contents = readJson(packageJson, host as { readFile: (filename: string) => string | undefined; }); // Cast to assert that readFile is defined
+        const contents = readJson(packageJson, host); // Cast to assert that readFile is defined
         // Provide completions for all non @types dependencies
         for (const key of nodeModulesDependencyKeys) {
             const dependencies: object | undefined = (contents as any)[key];

src/services/symbolDisplay.ts

@@ -105,7 +105,6 @@ import {
     Type,
     TypeChecker,
     TypeFormatFlags,
-    TypeParameter,
     typeToDisplayParts,
     VariableDeclaration,
     WriterContextOut,
@@ -699,7 +698,7 @@ function getSymbolDisplayPartsDocumentationAndSymbolKindWorker(
                     if (type.symbol && type.symbol.flags & SymbolFlags.TypeParameter && symbolKind !== ScriptElementKind.indexSignatureElement) {
                         const typeParameterParts = mapToDisplayParts(writer => {
                             const param = typeChecker.typeParameterToDeclaration(
-                                type as TypeParameter,
+                                type,
                                 enclosingDeclaration,
                                 symbolDisplayNodeBuilderFlags,
                                 /*internalFlags*/ undefined,

src/testRunner/projectsRunner.ts

@@ -282,7 +282,7 @@ class ProjectTestCase {
                     }
 
                     const content = Utils.removeTestPathPrefixes(output.text, /*retainTrailingDirectorySeparator*/ true);
-                    Harness.Baseline.runBaseline(this.getBaselineFolder(this.compilerResult.moduleKind) + diskRelativeName, content as string | null); // eslint-disable-line no-restricted-syntax
+                    Harness.Baseline.runBaseline(this.getBaselineFolder(this.compilerResult.moduleKind) + diskRelativeName, content);
                 }
                 catch (e) {
                     errs.push(e);

src/testRunner/unittests/tsserver/inlayHints.ts

@@ -38,7 +38,7 @@ describe("unittests:: tsserver:: inlayHints::", () => {
             arguments: {
                 preferences: {
                     includeInlayParameterNameHints: "all",
-                } as ts.UserPreferences,
+                },
             },
         });
         verifyInlayHintResponse(session);

src/testRunner/unittests/tsserver/projects.ts

@@ -927,20 +927,20 @@ describe("unittests:: tsserver:: projects::", () => {
             arguments: {
                 file: f1.path,
             },
-        } as ts.server.protocol.OpenRequest);
+        });
         session.executeCommandSeq({
             command: ts.server.protocol.CommandTypes.Close,
             arguments: {
                 file: f1.path,
             },
-        } as ts.server.protocol.CloseRequest);
+        });
         session.executeCommandSeq({
             command: ts.server.protocol.CommandTypes.Geterr,
             arguments: {
                 delay: 0,
                 files: [f1.path],
             },
-        } as ts.server.protocol.GeterrRequest);
+        });
         baselineTsserverLogs("projects", "getting errors from closed script info does not throw exception because of getting project from orphan script info", session);
     });
 

src/testRunner/unittests/tsserver/session.ts

@@ -193,7 +193,7 @@ describe("unittests:: tsserver:: Session:: General functionality", () => {
                     newLine: ts.NewLineKind.LineFeed,
                     moduleResolution: ts.ModuleResolutionKind.Node10,
                     allowNonTsExtensions: true, // injected by tsserver
-                } as ts.CompilerOptions,
+                },
             );
         });