Improve go-to-definition and implement go-to-type-definition (#1405)

Author: ahejlsberg

internal/ast/ast.go

@@ -2785,6 +2785,10 @@ func (node *SwitchStatement) computeSubtreeFacts() SubtreeFacts {
 		propagateSubtreeFacts(node.CaseBlock)
 }
 
+func IsSwitchStatement(node *Node) bool {
+	return node.Kind == KindSwitchStatement
+}
+
 // CaseBlock
 
 type CaseBlock struct {

internal/binder/binder.go

@@ -2758,7 +2758,7 @@ func (b *Binder) errorOrSuggestionOnRange(isError bool, startNode *ast.Node, end
 // If so, the node _must_ be in the current file (as that's the only way anything could have traversed to it to yield it as the error node)
 // This version of `createDiagnosticForNode` uses the binder's context to account for this, and always yields correct diagnostics even in these situations.
 func (b *Binder) createDiagnosticForNode(node *ast.Node, message *diagnostics.Message, args ...any) *ast.Diagnostic {
-	return ast.NewDiagnostic(b.file, GetErrorRangeForNode(b.file, node), message, args...)
+	return ast.NewDiagnostic(b.file, scanner.GetErrorRangeForNode(b.file, node), message, args...)
 }
 
 func (b *Binder) addDiagnostic(diagnostic *ast.Diagnostic) {
@@ -2855,83 +2855,3 @@ func isAssignmentDeclaration(decl *ast.Node) bool {
 func isEffectiveModuleDeclaration(node *ast.Node) bool {
 	return ast.IsModuleDeclaration(node) || ast.IsIdentifier(node)
 }
-
-func getErrorRangeForArrowFunction(sourceFile *ast.SourceFile, node *ast.Node) core.TextRange {
-	pos := scanner.SkipTrivia(sourceFile.Text(), node.Pos())
-	body := node.AsArrowFunction().Body
-	if body != nil && body.Kind == ast.KindBlock {
-		startLine, _ := scanner.GetLineAndCharacterOfPosition(sourceFile, body.Pos())
-		endLine, _ := scanner.GetLineAndCharacterOfPosition(sourceFile, body.End())
-		if startLine < endLine {
-			// The arrow function spans multiple lines,
-			// make the error span be the first line, inclusive.
-			return core.NewTextRange(pos, scanner.GetEndLinePosition(sourceFile, startLine))
-		}
-	}
-	return core.NewTextRange(pos, node.End())
-}
-
-func GetErrorRangeForNode(sourceFile *ast.SourceFile, node *ast.Node) core.TextRange {
-	errorNode := node
-	switch node.Kind {
-	case ast.KindSourceFile:
-		pos := scanner.SkipTrivia(sourceFile.Text(), 0)
-		if pos == len(sourceFile.Text()) {
-			return core.NewTextRange(0, 0)
-		}
-		return scanner.GetRangeOfTokenAtPosition(sourceFile, pos)
-	// This list is a work in progress. Add missing node kinds to improve their error spans
-	case ast.KindFunctionDeclaration, ast.KindMethodDeclaration:
-		if node.Flags&ast.NodeFlagsReparsed != 0 {
-			errorNode = node
-			break
-		}
-		fallthrough
-	case ast.KindVariableDeclaration, ast.KindBindingElement, ast.KindClassDeclaration, ast.KindClassExpression, ast.KindInterfaceDeclaration,
-		ast.KindModuleDeclaration, ast.KindEnumDeclaration, ast.KindEnumMember, ast.KindFunctionExpression,
-		ast.KindGetAccessor, ast.KindSetAccessor, ast.KindTypeAliasDeclaration, ast.KindJSTypeAliasDeclaration, ast.KindPropertyDeclaration,
-		ast.KindPropertySignature, ast.KindNamespaceImport:
-		errorNode = ast.GetNameOfDeclaration(node)
-	case ast.KindArrowFunction:
-		return getErrorRangeForArrowFunction(sourceFile, node)
-	case ast.KindCaseClause, ast.KindDefaultClause:
-		start := scanner.SkipTrivia(sourceFile.Text(), node.Pos())
-		end := node.End()
-		statements := node.AsCaseOrDefaultClause().Statements.Nodes
-		if len(statements) != 0 {
-			end = statements[0].Pos()
-		}
-		return core.NewTextRange(start, end)
-	case ast.KindReturnStatement, ast.KindYieldExpression:
-		pos := scanner.SkipTrivia(sourceFile.Text(), node.Pos())
-		return scanner.GetRangeOfTokenAtPosition(sourceFile, pos)
-	case ast.KindSatisfiesExpression:
-		pos := scanner.SkipTrivia(sourceFile.Text(), node.AsSatisfiesExpression().Expression.End())
-		return scanner.GetRangeOfTokenAtPosition(sourceFile, pos)
-	case ast.KindConstructor:
-		if node.Flags&ast.NodeFlagsReparsed != 0 {
-			errorNode = node
-			break
-		}
-		scanner := scanner.GetScannerForSourceFile(sourceFile, node.Pos())
-		start := scanner.TokenStart()
-		for scanner.Token() != ast.KindConstructorKeyword && scanner.Token() != ast.KindStringLiteral && scanner.Token() != ast.KindEndOfFile {
-			scanner.Scan()
-		}
-		return core.NewTextRange(start, scanner.TokenEnd())
-		// !!!
-		// case KindJSDocSatisfiesTag:
-		// 	pos := scanner.SkipTrivia(sourceFile.Text(), node.tagName.pos)
-		// 	return scanner.GetRangeOfTokenAtPosition(sourceFile, pos)
-	}
-	if errorNode == nil {
-		// If we don't have a better node, then just set the error on the first token of
-		// construct.
-		return scanner.GetRangeOfTokenAtPosition(sourceFile, node.Pos())
-	}
-	pos := errorNode.Pos()
-	if !ast.NodeIsMissing(errorNode) && !ast.IsJsxText(errorNode) {
-		pos = scanner.SkipTrivia(sourceFile.Text(), pos)
-	}
-	return core.NewTextRange(pos, errorNode.End())
-}

internal/checker/checker.go

@@ -30263,6 +30263,22 @@ func (c *Checker) getSymbolAtLocation(node *ast.Node, ignoreErrors bool) *ast.Sy
 	}
 }
 
+func (c *Checker) getIndexSignaturesAtLocation(node *ast.Node) []*ast.Node {
+	var signatures []*ast.Node
+	if ast.IsIdentifier(node) && ast.IsPropertyAccessExpression(node.Parent) && node.Parent.Name() == node {
+		keyType := c.getLiteralTypeFromPropertyName(node)
+		objectType := c.getTypeOfExpression(node.Parent.Expression())
+		for _, t := range objectType.Distributed() {
+			for _, info := range c.getApplicableIndexInfos(t, keyType) {
+				if info.declaration != nil {
+					signatures = core.AppendIfUnique(signatures, info.declaration)
+				}
+			}
+		}
+	}
+	return signatures
+}
+
 func (c *Checker) getSymbolOfNameOrPropertyAccessExpression(name *ast.Node) *ast.Symbol {
 	if ast.IsDeclarationName(name) {
 		return c.getSymbolOfNode(name.Parent)

internal/checker/exports.go

@@ -142,3 +142,11 @@ func (c *Checker) GetTypeOfPropertyOfType(t *Type, name string) *Type {
 func (c *Checker) GetContextualTypeForArgumentAtIndex(node *ast.Node, argIndex int) *Type {
 	return c.getContextualTypeForArgumentAtIndex(node, argIndex)
 }
+
+func (c *Checker) GetIndexSignaturesAtLocation(node *ast.Node) []*ast.Node {
+	return c.getIndexSignaturesAtLocation(node)
+}
+
+func (c *Checker) GetResolvedSymbol(node *ast.Node) *ast.Symbol {
+	return c.getResolvedSymbol(node)
+}

internal/checker/services.go

@@ -618,3 +618,68 @@ func (c *Checker) GetTypeParameterAtPosition(s *Signature, pos int) *Type {
 	}
 	return t
 }
+
+func (c *Checker) GetContextualDeclarationsForObjectLiteralElement(objectLiteral *ast.Node, name string) []*ast.Node {
+	var result []*ast.Node
+	if t := c.getApparentTypeOfContextualType(objectLiteral, ContextFlagsNone); t != nil {
+		for _, t := range t.Distributed() {
+			prop := c.getPropertyOfType(t, name)
+			if prop != nil {
+				for _, declaration := range prop.Declarations {
+					result = core.AppendIfUnique(result, declaration)
+				}
+			} else {
+				for _, info := range c.getApplicableIndexInfos(t, c.getStringLiteralType(name)) {
+					if info.declaration != nil {
+						result = core.AppendIfUnique(result, info.declaration)
+					}
+				}
+			}
+		}
+	}
+	return result
+}
+
+var knownGenericTypeNames = map[string]struct{}{
+	"Array":            {},
+	"ArrayLike":        {},
+	"ReadonlyArray":    {},
+	"Promise":          {},
+	"PromiseLike":      {},
+	"Iterable":         {},
+	"IterableIterator": {},
+	"AsyncIterable":    {},
+	"Set":              {},
+	"WeakSet":          {},
+	"ReadonlySet":      {},
+	"Map":              {},
+	"WeakMap":          {},
+	"ReadonlyMap":      {},
+	"Partial":          {},
+	"Required":         {},
+	"Readonly":         {},
+	"Pick":             {},
+	"Omit":             {},
+	"NonNullable":      {},
+}
+
+func isKnownGenericTypeName(name string) bool {
+	_, exists := knownGenericTypeNames[name]
+	return exists
+}
+
+func (c *Checker) GetFirstTypeArgumentFromKnownType(t *Type) *Type {
+	if t.objectFlags&ObjectFlagsReference != 0 && isKnownGenericTypeName(t.symbol.Name) {
+		symbol := c.getGlobalSymbol(t.symbol.Name, ast.SymbolFlagsType, nil)
+		if symbol != nil && symbol == t.Target().symbol {
+			return core.FirstOrNil(c.getTypeArguments(t))
+		}
+	}
+	if t.alias != nil && isKnownGenericTypeName(t.alias.symbol.Name) {
+		symbol := c.getGlobalSymbol(t.alias.symbol.Name, ast.SymbolFlagsType, nil)
+		if symbol != nil && symbol == t.alias.symbol {
+			return core.FirstOrNil(t.alias.typeArguments)
+		}
+	}
+	return nil
+}

internal/checker/utilities.go

@@ -23,7 +23,7 @@ func NewDiagnosticForNode(node *ast.Node, message *diagnostics.Message, args ...
 	var loc core.TextRange
 	if node != nil {
 		file = ast.GetSourceFileOfNode(node)
-		loc = binder.GetErrorRangeForNode(file, node)
+		loc = scanner.GetErrorRangeForNode(file, node)
 	}
 	return ast.NewDiagnostic(file, loc, message, args...)
 }