Enable staticcheck

.golangci.yml

@@ -38,6 +38,7 @@ linters:
     - perfsprint
     - predeclared
     - reassign
+    - staticcheck
     - testableexamples
     - tparallel
     - unconvert
@@ -52,7 +53,6 @@ linters:
     # - gocritic
     # - gosec
     # - revive
-    # - staticcheck
     # - testifylint
     # - unparam
     # - unused
@@ -62,6 +62,20 @@ linters:
       customlint:
         type: module
 
+    staticcheck:
+      checks:
+        - all
+        - -QF1001
+        - -QF1003
+        - -SA6005
+        - -SA9003
+        - -ST1000
+        - -ST1003
+        - -ST1016
+        - -ST1020
+        - -ST1021
+        - -ST1022
+
   exclusions:
     presets:
       - comments

internal/astnav/tokens_test.go

@@ -252,15 +252,15 @@ func writeRangeDiff(output *strings.Builder, file *ast.SourceFile, diff tokenDif
 		output.WriteString("\n\n")
 	}
 
-	output.WriteString(fmt.Sprintf("〚Positions: [%d, %d]〛\n", rng.Pos(), rng.End()))
-	output.WriteString(fmt.Sprintf("【TS: %s [%d, %d)】\n", diff.tsToken.Kind, diff.tsToken.Pos, diff.tsToken.End))
-	output.WriteString(fmt.Sprintf("《Go: %s [%d, %d)》\n", diff.goToken.Kind, diff.goToken.Pos, diff.goToken.End))
+	fmt.Fprintf(output, "〚Positions: [%d, %d]〛\n", rng.Pos(), rng.End())
+	fmt.Fprintf(output, "【TS: %s [%d, %d)】\n", diff.tsToken.Kind, diff.tsToken.Pos, diff.tsToken.End)
+	fmt.Fprintf(output, "《Go: %s [%d, %d)》\n", diff.goToken.Kind, diff.goToken.Pos, diff.goToken.End)
 	for line := contextStart; line <= contextEnd; line++ {
 		if truncate, skipTo := shouldTruncate(line); truncate {
-			output.WriteString(fmt.Sprintf("%s │........ %d lines omitted ........\n", strings.Repeat(" ", digits), skipTo-line+1))
+			fmt.Fprintf(output, "%s │........ %d lines omitted ........\n", strings.Repeat(" ", digits), skipTo-line+1)
 			line = skipTo
 		}
-		output.WriteString(fmt.Sprintf("%*d │", digits, line+1))
+		fmt.Fprintf(output, "%*d │", digits, line+1)
 		end := len(file.Text()) + 1
 		if line < len(lines)-1 {
 			end = int(lines[line+1])

internal/binder/binder.go

@@ -246,7 +246,7 @@ func (b *Binder) declareSymbolEx(symbolTable ast.SymbolTable, parent *ast.Symbol
 						}
 					}
 				}
-				var declarationName *ast.Node = ast.GetNameOfDeclaration(node)
+				declarationName := ast.GetNameOfDeclaration(node)
 				if declarationName == nil {
 					declarationName = node
 				}
@@ -261,7 +261,7 @@ func (b *Binder) declareSymbolEx(symbolTable ast.SymbolTable, parent *ast.Symbol
 					diag.AddRelatedInfo(b.createDiagnosticForNode(node, diagnostics.Did_you_mean_0, "export type { "+node.AsTypeAliasDeclaration().Name().AsIdentifier().Text+" }"))
 				}
 				for index, declaration := range symbol.Declarations {
-					var decl *ast.Node = ast.GetNameOfDeclaration(declaration)
+					decl := ast.GetNameOfDeclaration(declaration)
 					if decl == nil {
 						decl = declaration
 					}
@@ -2035,7 +2035,7 @@ func (b *Binder) bindCaseBlock(node *ast.Node) {
 	switchStatement := node.Parent
 	clauses := node.AsCaseBlock().Clauses.Nodes
 	isNarrowingSwitch := switchStatement.Expression().Kind == ast.KindTrueKeyword || isNarrowingExpression(switchStatement.Expression())
-	var fallthroughFlow *ast.FlowNode = b.unreachableFlow
+	fallthroughFlow := b.unreachableFlow
 	for i := 0; i < len(clauses); i++ {
 		clauseStart := i
 		for len(clauses[i].AsCaseOrDefaultClause().Statements.Nodes) == 0 && i+1 < len(clauses) {

internal/checker/checker.go

@@ -1594,13 +1594,6 @@ func (c *Checker) getSuggestedLibForNonExistentName(name string) string {
 	return ""
 }
 
-func (c *Checker) getPrimitiveAliasSymbols() {
-	var symbols []*ast.Symbol
-	for _, name := range []string{"string", "number", "boolean", "object", "bigint", "symbol"} {
-		symbols = append(symbols, c.newSymbol(ast.SymbolFlagsTypeAlias, name))
-	}
-}
-
 func (c *Checker) getSuggestedSymbolForNonexistentSymbol(location *ast.Node, outerName string, meaning ast.SymbolFlags) *ast.Symbol {
 	return c.resolveNameForSymbolSuggestion(location, outerName, meaning, nil /*nameNotFoundMessage*/, false /*isUse*/, false /*excludeGlobals*/)
 }
@@ -10194,10 +10187,10 @@ func (c *Checker) checkPrefixUnaryExpression(node *ast.Node) *Type {
 	case ast.KindExclamationToken:
 		c.checkTruthinessOfType(operandType, expr.Operand)
 		facts := c.getTypeFacts(operandType, TypeFactsTruthy|TypeFactsFalsy)
-		switch {
-		case facts == TypeFactsTruthy:
+		switch facts {
+		case TypeFactsTruthy:
 			return c.falseType
-		case facts == TypeFactsFalsy:
+		case TypeFactsFalsy:
 			return c.trueType
 		default:
 			return c.booleanType
@@ -12406,10 +12399,10 @@ func (c *Checker) checkObjectLiteral(node *ast.Node, checkMode CheckMode) *Type
 		}
 		if ast.IsPropertyAssignment(memberDecl) || ast.IsShorthandPropertyAssignment(memberDecl) || ast.IsObjectLiteralMethod(memberDecl) {
 			var t *Type
-			switch {
-			case memberDecl.Kind == ast.KindPropertyAssignment:
+			switch memberDecl.Kind {
+			case ast.KindPropertyAssignment:
 				t = c.checkPropertyAssignment(memberDecl, checkMode)
-			case memberDecl.Kind == ast.KindShorthandPropertyAssignment:
+			case ast.KindShorthandPropertyAssignment:
 				var expr *ast.Node
 				if !inDestructuringPattern {
 					expr = memberDecl.AsShorthandPropertyAssignment().ObjectAssignmentInitializer
@@ -15562,7 +15555,7 @@ func (c *Checker) getBaseConstructorTypeOfClass(t *Type) *Type {
 		err := c.error(baseTypeNode.Expression(), diagnostics.Type_0_is_not_a_constructor_function_type, c.TypeToString(baseConstructorType))
 		if baseConstructorType.flags&TypeFlagsTypeParameter != 0 {
 			constraint := c.getConstraintFromTypeParameter(baseConstructorType)
-			var ctorReturn *Type = c.unknownType
+			ctorReturn := c.unknownType
 			if constraint != nil {
 				ctorSigs := c.getSignaturesOfType(constraint, SignatureKindConstruct)
 				if len(ctorSigs) != 0 {
@@ -17041,12 +17034,12 @@ func (c *Checker) getOptionalType(t *Type, isProperty bool) *Type {
 // Add undefined or null or both to a type if they are missing.
 func (c *Checker) getNullableType(t *Type, flags TypeFlags) *Type {
 	missing := (flags & ^t.flags) & (TypeFlagsUndefined | TypeFlagsNull)
-	switch {
-	case missing == 0:
+	switch missing {
+	case 0:
 		return t
-	case missing == TypeFlagsUndefined:
+	case TypeFlagsUndefined:
 		return c.getUnionType([]*Type{t, c.undefinedType})
-	case missing == TypeFlagsNull:
+	case TypeFlagsNull:
 		return c.getUnionType([]*Type{t, c.nullType})
 	}
 	return c.getUnionType([]*Type{t, c.undefinedType, c.nullType})
@@ -18469,7 +18462,7 @@ func (c *Checker) getReturnTypeFromBody(fn *ast.Node, checkMode CheckMode) *Type
 	var returnType *Type
 	var yieldType *Type
 	var nextType *Type
-	var fallbackReturnType *Type = c.voidType
+	fallbackReturnType := c.voidType
 	switch {
 	case !ast.IsBlock(body):
 		returnType = c.checkExpressionCachedEx(body, checkMode & ^CheckModeSkipGenericFunctions)
@@ -19480,7 +19473,7 @@ func (c *Checker) getUnionSignatures(signatureLists [][]*Signature) []*Signature
 		// nature and having overloads in multiple constituents would necessitate making a power set of signatures from the type, whose
 		// ordering would be non-obvious)
 		masterList := signatureLists[indexWithLengthOverOne]
-		var results []*Signature = slices.Clone(masterList)
+		results := slices.Clone(masterList)
 		for _, signatures := range signatureLists {
 			if !core.Same(signatures, masterList) {
 				signature := signatures[0]
@@ -27501,10 +27494,10 @@ func (c *Checker) getContextualTypeForArgument(callTarget *ast.Node, arg *ast.No
 
 func (c *Checker) getContextualTypeForArgumentAtIndex(callTarget *ast.Node, argIndex int) *Type {
 	if ast.IsImportCall(callTarget) {
-		switch {
-		case argIndex == 0:
+		switch argIndex {
+		case 0:
 			return c.stringType
-		case argIndex == 1:
+		case 1:
 			return c.getGlobalImportCallOptionsType()
 		default:
 			return c.anyType
@@ -28874,10 +28867,10 @@ func (c *Checker) getGlobalNonNullableTypeInstantiation(t *Type) *Type {
 }
 
 func (c *Checker) convertAutoToAny(t *Type) *Type {
-	switch {
-	case t == c.autoType:
+	switch t {
+	case c.autoType:
 		return c.anyType
-	case t == c.autoArrayType:
+	case c.autoArrayType:
 		return c.anyArrayType
 	}
 	return t

internal/checker/flow.go

@@ -1976,7 +1976,7 @@ func (c *Checker) getSwitchClauseTypeOfWitnesses(node *ast.Node) []string {
 
 // Return the combined not-equal type facts for all cases except those between the start and end indices.
 func (c *Checker) getNotEqualFactsFromTypeofSwitch(start int, end int, witnesses []string) TypeFacts {
-	var facts TypeFacts = TypeFactsNone
+	facts := TypeFactsNone
 	for i, witness := range witnesses {
 		if (i < start || i >= end) && witness != "" {
 			f, ok := typeofNEFacts[witness]

internal/checker/grammarchecks.go

@@ -1491,7 +1491,7 @@ func (c *Checker) checkGrammarBreakOrContinueStatement(node *ast.Node) bool {
 		panic(fmt.Sprintf("Unexpected node kind %q", node.Kind))
 	}
 
-	var current *ast.Node = node
+	current := node
 	for current != nil {
 		if ast.IsFunctionLikeOrClassStaticBlockDeclaration(current) {
 			return c.grammarErrorOnNode(node, diagnostics.Jump_target_cannot_cross_function_boundary)
@@ -1794,14 +1794,14 @@ func (c *Checker) checkGrammarForDisallowedBlockScopedVariableStatement(node *as
 		blockScopeKind := c.getCombinedNodeFlagsCached(node.DeclarationList) & ast.NodeFlagsBlockScoped
 		if blockScopeKind != 0 {
 			var keyword string
-			switch {
-			case blockScopeKind == ast.NodeFlagsLet:
+			switch blockScopeKind {
+			case ast.NodeFlagsLet:
 				keyword = "let"
-			case blockScopeKind == ast.NodeFlagsConst:
+			case ast.NodeFlagsConst:
 				keyword = "const"
-			case blockScopeKind == ast.NodeFlagsUsing:
+			case ast.NodeFlagsUsing:
 				keyword = "using"
-			case blockScopeKind == ast.NodeFlagsAwaitUsing:
+			case ast.NodeFlagsAwaitUsing:
 				keyword = "await using"
 			default:
 				panic("Unknown BlockScope flag")

internal/checker/inference.go

@@ -579,10 +579,10 @@ func (c *Checker) inferToTemplateLiteralType(n *InferenceState, source *Type, ta
 								case left.flags&TypeFlagsBoolean != 0:
 									return left
 								case right.flags&TypeFlagsBoolean != 0:
-									switch {
-									case str == "true":
+									switch str {
+									case "true":
 										return c.trueType
-									case str == "false":
+									case "false":
 										return c.falseType
 									default:
 										return c.booleanType

internal/checker/jsx.go

@@ -602,7 +602,7 @@ func (c *Checker) createJsxAttributesTypeFromAttributesProperty(openingLikeEleme
 	}
 	// We have to check that openingElement of the parent is the one we are visiting as this may not be true for selfClosingElement
 	if parent != nil && parent.AsJsxElement().OpeningElement == openingLikeElement && len(getSemanticJsxChildren(parent.AsJsxElement().Children.Nodes)) != 0 {
-		var childTypes []*Type = c.checkJsxChildren(parent, checkMode)
+		var childTypes = c.checkJsxChildren(parent, checkMode)
 		if !hasSpreadAnyType && jsxChildrenPropertyName != ast.InternalSymbolNameMissing && jsxChildrenPropertyName != "" {
 			// Error if there is a attribute named "children" explicitly specified and children element.
 			// This is because children element will overwrite the value from attributes.

internal/checker/relater.go

@@ -4453,10 +4453,10 @@ func (r *Relater) constructorVisibilitiesAreCompatible(sourceSignature *Signatur
 // See signatureAssignableTo, compareSignaturesIdentical
 func (r *Relater) signatureRelatedTo(source *Signature, target *Signature, erase bool, reportErrors bool, intersectionState IntersectionState) Ternary {
 	checkMode := SignatureCheckModeNone
-	switch {
-	case r.relation == r.c.subtypeRelation:
+	switch r.relation {
+	case r.c.subtypeRelation:
 		checkMode = SignatureCheckModeStrictTopSignature
-	case r.relation == r.c.strictSubtypeRelation:
+	case r.c.strictSubtypeRelation:
 		checkMode = SignatureCheckModeStrictTopSignature | SignatureCheckModeStrictArity
 	}
 	if erase {

internal/compiler/packagejson/cache.go

@@ -20,15 +20,15 @@ type PackageJson struct {
 
 func (p *PackageJson) GetVersionPaths(trace func(string)) VersionPaths {
 	p.once.Do(func() {
-		if p.Fields.TypesVersions.Type == JSONValueTypeNotPresent {
+		if p.TypesVersions.Type == JSONValueTypeNotPresent {
 			if trace != nil {
 				trace(diagnostics.X_package_json_does_not_have_a_0_field.Format("typesVersions"))
 			}
 			return
 		}
-		if p.Fields.TypesVersions.Type != JSONValueTypeObject {
+		if p.TypesVersions.Type != JSONValueTypeObject {
 			if trace != nil {
-				trace(diagnostics.Expected_type_of_0_field_in_package_json_to_be_1_got_2.Format("typesVersions", "object", p.Fields.TypesVersions.Type.String()))
+				trace(diagnostics.Expected_type_of_0_field_in_package_json_to_be_1_got_2.Format("typesVersions", "object", p.TypesVersions.Type.String()))
 			}
 			return
 		}

internal/parser/jsdoc.go

@@ -1423,7 +1423,7 @@ func (p *Parser) parseOptionalJsdoc(t ast.Kind) bool {
 }
 
 func (p *Parser) parseJSDocEntityName() *ast.EntityName {
-	var entity *ast.EntityName = p.parseJSDocIdentifierName(nil)
+	entity := p.parseJSDocIdentifierName(nil)
 	if p.parseOptional(ast.KindOpenBracketToken) {
 		p.parseExpected(ast.KindCloseBracketToken)
 		// Note that y[] is accepted as an entity name, but the postfix brackets are not saved for checking.

internal/parser/parser.go

@@ -6601,7 +6601,7 @@ func processPragmasIntoFields(context *ast.SourceFile /* !!! reportDiagnostic fu
 		case "ts-check", "ts-nocheck":
 			// _last_ of either nocheck or check in a file is the "winner"
 			for _, directive := range context.Pragmas {
-				if context.CheckJsDirective == nil || directive.TextRange.Pos() > context.CheckJsDirective.Range.Pos() {
+				if context.CheckJsDirective == nil || directive.Pos() > context.CheckJsDirective.Range.Pos() {
 					context.CheckJsDirective = &ast.CheckJsDirective{
 						Enabled: directive.Name == "ts-check",
 						Range:   directive.CommentRange,

internal/scanner/scanner.go

@@ -1361,10 +1361,8 @@ func (s *Scanner) ScanJSDocToken() ast.Kind {
 
 	if isIdentifierStart(ch, s.languageVersion) {
 		char := ch
-		for {
-			if s.pos >= len(s.text) {
-				break
-			}
+		for s.pos < len(s.text) {
+
 			char, size = s.charAndSize()
 			if !isIdentifierPart(char, s.languageVersion) && char != '-' {
 				break

internal/testutil/harnessutil/sourcemap_recorder.go

@@ -17,7 +17,7 @@ type writerAggregator struct {
 }
 
 func (w *writerAggregator) WriteStringF(format string, args ...any) {
-	w.WriteString(fmt.Sprintf(format, args...))
+	fmt.Fprintf(w, format, args...)
 }
 
 func (w *writerAggregator) WriteLine(s string) {
@@ -58,7 +58,7 @@ func (d *sourceMapDecoder) decodeNextEncodedSourceMapSpan() *decodedMapping {
 			sourceMapSpan: d.mappings.State(),
 		}
 		if mapping.error == nil {
-			mapping.error = errors.New("No encoded entry found")
+			mapping.error = errors.New("no encoded entry found")
 		}
 		return mapping
 	}

internal/testutil/tsbaseline/error_baseline.go

@@ -96,7 +96,7 @@ func iterateErrorBaseline(t *testing.T, inputFiles []*harnessutil.TestFile, inpu
 		var errLines []string
 		for _, line := range strings.Split(removeTestPathPrefixes(message, false), "\n") {
 			line = strings.TrimSuffix(line, "\r")
-			if len(line) < 0 {
+			if len(line) == 0 {
 				continue
 			}
 			out := fmt.Sprintf("!!! %s TS%d: %s", diag.Category().Name(), diag.Code(), line)

internal/testutil/tsbaseline/sourcemap_baseline.go

@@ -87,11 +87,7 @@ func createSourceMapPreviewLink(sourceMap *harnessutil.TestFile, result *harness
 		return ""
 	}
 
-	var sourceTDs []*harnessutil.TestFile
-	////if len(sourcemapJSON.Sources) == len(inputsAndOutputs.Inputs) {
-	////	sourceTDs = inputsAndOutputs.Inputs
-	////} else {
-	sourceTDs = core.Map(sourcemapJSON.Sources, func(s string) *harnessutil.TestFile {
+	var sourceTDs = core.Map(sourcemapJSON.Sources, func(s string) *harnessutil.TestFile {
 		return core.Find(result.Inputs(), func(td *harnessutil.TestFile) bool {
 			return strings.HasSuffix(td.UnitName, s)
 		})

internal/tsoptions/tsconfigparsing.go

@@ -953,7 +953,7 @@ func parseConfig(
 	if ownConfig.extendedConfigPath != nil {
 		// copy the resolution stack so it is never reused between branches in potential diamond-problem scenarios.
 		resolutionStack = append(resolutionStack, resolvedPath)
-		var result *extendsResult = &extendsResult{
+		result := &extendsResult{
 			options: &core.CompilerOptions{},
 		}
 		if reflect.TypeOf(ownConfig.extendedConfigPath).Kind() == reflect.String {
@@ -1152,7 +1152,7 @@ func parseJsonConfigFileContentWorker(
 	}
 
 	getProjectReferences := func(basePath string) []core.ProjectReference {
-		var projectReferences []core.ProjectReference = []core.ProjectReference{}
+		projectReferences := []core.ProjectReference{}
 		newReferencesOfRaw := getPropFromRaw("references", func(element any) bool { return reflect.TypeOf(element) == orderedMapType }, "object")
 		if newReferencesOfRaw.sliceValue != nil {
 			for _, reference := range newReferencesOfRaw.sliceValue {
@@ -1430,7 +1430,6 @@ func getFileNamesFromConfigSpecs(
 	host vfs.FS,
 	extraFileExtensions []fileExtensionInfo,
 ) []string {
-	extraFileExtensions = []fileExtensionInfo{}
 	basePath = tspath.NormalizePath(basePath)
 	keyMappper := func(value string) string { return tspath.GetCanonicalFileName(value, host.UseCaseSensitiveFileNames()) }
 	// Literal file names (provided via the "files" array in tsconfig.json) are stored in a