More type checking fixes (microsoft#786)

Author: ahejlsberg

internal/checker/checker.go

@@ -14504,7 +14504,7 @@ func (c *Checker) resolveQualifiedName(name *ast.Node, left *ast.Node, right *as
 	}
 	text := right.AsIdentifier().Text
 	symbol := c.getMergedSymbol(c.getSymbol(c.getExportsOfSymbol(namespace), text, meaning))
-	if symbol != nil && namespace.Flags&ast.SymbolFlagsAlias != 0 {
+	if symbol == nil && namespace.Flags&ast.SymbolFlagsAlias != 0 {
 		// `namespace` can be resolved further if there was a symbol merge with a re-export
 		symbol = c.getMergedSymbol(c.getSymbol(c.getExportsOfSymbol(c.resolveAlias(namespace)), text, meaning))
 	}
@@ -15200,16 +15200,26 @@ func (c *Checker) getTypeOfVariableOrParameterOrPropertyWorker(symbol *ast.Symbo
 	if symbol == c.requireSymbol {
 		return c.anyType
 	}
-	// !!! Handle SymbolFlagsModuleExports
+	if symbol.Flags&ast.SymbolFlagsModuleExports != 0 && symbol.ValueDeclaration != nil {
+		fileSymbol := c.getSymbolOfDeclaration(ast.GetSourceFileOfNode(symbol.ValueDeclaration).AsNode())
+		result := c.newSymbol(fileSymbol.Flags, "exports")
+		result.Parent = symbol
+		result.Declarations = fileSymbol.Declarations
+		result.ValueDeclaration = fileSymbol.ValueDeclaration
+		result.Members = maps.Clone(fileSymbol.Members)
+		result.Exports = maps.Clone(fileSymbol.Exports)
+		members := make(ast.SymbolTable, 1)
+		members["exports"] = result
+		return c.newAnonymousType(symbol, members, nil, nil, nil)
+	}
 	// Debug.assertIsDefined(symbol.valueDeclaration)
 	declaration := symbol.ValueDeclaration
-	// !!! Handle export default expressions
 	if ast.IsSourceFile(declaration) && ast.IsJsonSourceFile(declaration.AsSourceFile()) {
 		statements := declaration.AsSourceFile().Statements.Nodes
 		if len(statements) == 0 {
 			return c.emptyObjectType
 		}
-		return c.getWidenedType(c.getWidenedLiteralType(c.checkExpression(statements[0].AsExpressionStatement().Expression)))
+		return c.getWidenedType(c.getWidenedLiteralType(c.checkExpression(statements[0].Expression())))
 	}
 	// Handle variable, parameter or property
 	if !c.pushTypeResolution(symbol, TypeSystemPropertyNameType) {
@@ -17995,8 +18005,9 @@ func (c *Checker) addInheritedMembers(symbols ast.SymbolTable, baseSymbols []*as
 func (c *Checker) resolveDeclaredMembers(t *Type) *InterfaceType {
 	d := t.AsInterfaceType()
 	if !d.declaredMembersResolved {
+		members := c.getMembersOfSymbol(t.symbol)
 		d.declaredMembersResolved = true
-		d.declaredMembers = c.getMembersOfSymbol(t.symbol)
+		d.declaredMembers = members
 		d.declaredCallSignatures = c.getSignaturesOfSymbol(d.declaredMembers[ast.InternalSymbolNameCall])
 		d.declaredConstructSignatures = c.getSignaturesOfSymbol(d.declaredMembers[ast.InternalSymbolNameNew])
 		d.declaredIndexInfos = c.getIndexInfosOfSymbol(t.symbol)
@@ -20641,7 +20652,7 @@ func (c *Checker) getObjectTypeInstantiation(t *Type, m *TypeMapper, alias *Type
 		newAlias = c.instantiateTypeAlias(t.alias, m)
 	}
 	data := target.AsObjectType()
-	key := getTypeInstantiationKey(typeArguments, alias, t.objectFlags&ObjectFlagsSingleSignatureType != 0)
+	key := getTypeInstantiationKey(typeArguments, newAlias, t.objectFlags&ObjectFlagsSingleSignatureType != 0)
 	if data.instantiations == nil {
 		data.instantiations = make(map[string]*Type)
 		data.instantiations[getTypeInstantiationKey(typeParameters, target.alias, false)] = target

internal/parser/parser.go

@@ -343,7 +343,7 @@ func (p *Parser) parseSourceFileWorker() *ast.SourceFile {
 func (p *Parser) finishSourceFile(result *ast.SourceFile, isDeclarationFile bool) {
 	result.CommentDirectives = p.scanner.CommentDirectives()
 	result.Pragmas = getCommentPragmas(&p.factory, p.sourceText)
-	processPragmasIntoFields(result)
+	p.processPragmasIntoFields(result)
 	result.SetDiagnostics(attachFileToDiagnostics(p.diagnostics, result))
 	result.ExternalModuleIndicator = isFileProbablyExternalModule(result) // !!!
 	result.IsDeclarationFile = isDeclarationFile
@@ -6434,16 +6434,16 @@ func extractPragmas(commentRange ast.CommentRange, text string) []ast.Pragma {
 				}
 				argName := extractName(text, pos)
 				if argName == "" {
-					return nil
+					break
 				}
 				pos = skipBlanks(text, pos+len(argName))
 				if !match(text, pos, "=") {
-					return nil
+					break
 				}
 				pos = skipBlanks(text, pos+1)
 				value, ok := extractQuotedString(text, pos)
 				if !ok {
-					return nil
+					break
 				}
 				args[argName] = ast.PragmaArgument{
 					Name:      argName,
@@ -6483,6 +6483,9 @@ func extractPragmas(commentRange ast.CommentRange, text string) []ast.Pragma {
 			}
 			start := skipBlanks(text, pos+len(pragmaName)+1)
 			pos = skipNonBlanks(text, start)
+			if pos == start {
+				break
+			}
 			args := make(map[string]ast.PragmaArgument, 1)
 			args["factory"] = ast.PragmaArgument{
 				Name:      "factory",
@@ -6553,7 +6556,7 @@ func extractQuotedString(text string, pos int) (string, bool) {
 	return text[start:pos], true
 }
 
-func processPragmasIntoFields(context *ast.SourceFile /* !!! reportDiagnostic func(*ast.Diagnostic)*/) {
+func (p *Parser) processPragmasIntoFields(context *ast.SourceFile) {
 	context.CheckJsDirective = nil
 	context.ReferencedFiles = nil
 	context.TypeReferenceDirectives = nil
@@ -6569,10 +6572,10 @@ func processPragmasIntoFields(context *ast.SourceFile /* !!! reportDiagnostic fu
 			resolutionMode, resolutionModeOk := pragma.Args["resolution-mode"]
 			preserve, preserveOk := pragma.Args["preserve"]
 			noDefaultLib, noDefaultLibOk := pragma.Args["no-default-lib"]
-
-			if noDefaultLibOk && noDefaultLib.Value == "true" {
+			switch {
+			case noDefaultLibOk && noDefaultLib.Value == "true":
 				context.HasNoDefaultLib = true
-			} else if typesOk {
+			case typesOk:
 				var parsed core.ResolutionMode
 				if resolutionModeOk {
 					parsed = parseResolutionMode(resolutionMode.Value, types.Pos(), types.End() /*, reportDiagnostic*/)
@@ -6583,20 +6586,20 @@ func processPragmasIntoFields(context *ast.SourceFile /* !!! reportDiagnostic fu
 					ResolutionMode: parsed,
 					Preserve:       preserveOk && preserve.Value == "true",
 				})
-			} else if libOk {
+			case libOk:
 				context.LibReferenceDirectives = append(context.LibReferenceDirectives, &ast.FileReference{
 					TextRange: types.TextRange,
 					FileName:  lib.Value,
 					Preserve:  preserveOk && preserve.Value == "true",
 				})
-			} else if pathOk {
+			case pathOk:
 				context.ReferencedFiles = append(context.ReferencedFiles, &ast.FileReference{
 					TextRange: types.TextRange,
 					FileName:  path.Value,
 					Preserve:  preserveOk && preserve.Value == "true",
 				})
-			} else {
-				// reportDiagnostic(argMap.Pos, argMap.End-argMap.Pos, "Invalid reference directive syntax")
+			default:
+				p.parseErrorAtRange(pragma.TextRange, diagnostics.Invalid_reference_directive_syntax)
 			}
 		case "ts-check", "ts-nocheck":
 			// _last_ of either nocheck or check in a file is the "winner"
@@ -6610,7 +6613,7 @@ func processPragmasIntoFields(context *ast.SourceFile /* !!! reportDiagnostic fu
 			}
 
 		case "jsx", "jsxfrag", "jsximportsource", "jsxruntime":
-			// !!!
+			// Nothing to do here
 		default:
 			panic("Unhandled pragma kind: " + pragma.Name)
 		}