Support @deprecated marker on namespace aliases (fixes #62340)

tsc/internal/checker/checker.go

@@ -3078,10 +3078,26 @@ func (c *Checker) checkTypeReferenceOrImport(node *ast.Node) {
 				c.checkTypeArgumentConstraints(node, typeParameters)
 			}
 		}
-		symbol := c.getResolvedSymbolOrNil(node)
-		if symbol != nil {
-			if core.Some(symbol.Declarations(), func(d *ast.Node) bool { return ast.IsTypeDeclaration(d) && c.IsDeprecatedDeclaration(d) }) {
-				c.addDeprecatedSuggestion(c.getDeprecatedSuggestionNode(node), symbol.Declarations(), symbol.Name())
+		name := getTypeReferenceName(node)
+		var aliasSymbol *ast.Symbol
+		if name != nil {
+			aliasSymbol = c.resolveEntityName(name, ast.SymbolFlagsType, true /*ignoreErrors*/, true /*dontResolveAlias*/, nil /*location*/)
+		} else if ast.IsImportTypeNode(node) && !ast.NodeIsMissing(node.AsImportTypeNode().Qualifier) {
+			aliasSymbol = c.getResolvedSymbolOrNil(node.AsImportTypeNode().Qualifier)
+		}
+		if aliasSymbol != nil && aliasSymbol.Flags()&ast.SymbolFlagsAlias != 0 && aliasSymbol.Flags()&ast.SymbolFlagsType == 0 {
+			targetSymbol := c.resolveAliasWithDeprecationCheck(aliasSymbol, c.getDeprecatedSuggestionNode(node))
+			if targetSymbol != nil && core.Some(targetSymbol.Declarations(), func(d *ast.Node) bool {
+				return (ast.IsTypeDeclaration(d) || d.Kind == ast.KindImportEqualsDeclaration || d.Kind == ast.KindImportSpecifier || d.Kind == ast.KindExportSpecifier) && c.IsDeprecatedDeclaration(d)
+			}) {
+				c.addDeprecatedSuggestion(c.getDeprecatedSuggestionNode(node), targetSymbol.Declarations(), targetSymbol.Name())
+			}
+		} else {
+			symbol := c.getResolvedSymbolOrNil(node)
+			if symbol != nil {
+				if core.Some(symbol.Declarations(), func(d *ast.Node) bool { return ast.IsTypeDeclaration(d) && c.IsDeprecatedDeclaration(d) }) {
+					c.addDeprecatedSuggestion(c.getDeprecatedSuggestionNode(node), symbol.Declarations(), symbol.Name())
+				}
 			}
 		}
 	}
@@ -3122,6 +3138,14 @@ func (c *Checker) getDeprecatedSuggestionNode(node *ast.Node) *ast.Node {
 		if ast.IsQualifiedName(typeName) {
 			return typeName.AsQualifiedName().Right
 		}
+	case ast.KindImportType:
+		qualifier := node.AsImportTypeNode().Qualifier
+		if qualifier != nil {
+			if ast.IsQualifiedName(qualifier) {
+				return qualifier.AsQualifiedName().Right
+			}
+			return qualifier
+		}
 	}
 	return node
 }

tsc/internal/checker/checker_test.go

@@ -208,3 +208,61 @@ export type Initial = Box<"first">;
 	assert.Equal(t, c.TypeToString(initial), "Initial")
 	assert.Equal(t, len(c.GetDiagnostics(t.Context(), file)), 0)
 }
+
+func TestDeprecatedNamespaceAliasInTypeReference(t *testing.T) {
+	t.Parallel()
+
+	fs := bundled.WrapFS(vfstest.FromMap(map[string]string{
+		"/example.d.ts": `export type Bar = string | number;
+/** @deprecated */
+export type Baz = string | number;
+export { /** @deprecated */ Bar as Old } from './example';`,
+		"/values.d.ts": `export const val = 1;`,
+		"/foo.ts": `import * as example from './example';
+
+export { val } from './values';
+/** @deprecated */
+export type val = number;
+
+export namespace JSX {
+	/** @deprecated */
+	export type Foo = string | number;
+
+	/** @deprecated */
+	export import Bar = example.Bar;
+
+	export import Baz = example.Baz;
+
+	export import Old = example.Old;
+}
+
+let x: JSX.Foo;
+let y: JSX.Bar;
+let z: JSX.Baz;
+let o: JSX.Old;
+let m: val;
+let w: import('./foo').JSX.Bar;`,
+	}, tspath.CaseSensitive))
+	opts := &core.CompilerOptions{NoLib: core.TSTrue}
+	program := compiler.NewProgram(compiler.ProgramOptions{
+		Config: tsoptions.NewParsedCommandLine(opts, []tspath.RootedFilePath{"/example.d.ts", "/values.d.ts", "/foo.ts"}, nil, "/", fs.CaseSensitivity()),
+		Host:   compiler.NewCompilerHost(fs, bundled.LibPath(), nil, nil, nil),
+	})
+	program.BindSourceFiles()
+	c, done := program.GetTypeChecker(t.Context())
+	defer done()
+	file := program.GetSourceFile("/foo.ts")
+	var deprecatedSuggestions []*ast.Diagnostic
+	for _, s := range c.GetSuggestionDiagnostics(t.Context(), file) {
+		if s.ReportsDeprecated() {
+			deprecatedSuggestions = append(deprecatedSuggestions, s)
+		}
+	}
+	assert.Equal(t, len(deprecatedSuggestions), 6)
+	assert.Equal(t, deprecatedSuggestions[0].MessageArgs()[0], "Foo")
+	assert.Equal(t, deprecatedSuggestions[1].MessageArgs()[0], "Bar")
+	assert.Equal(t, deprecatedSuggestions[2].MessageArgs()[0], "Baz")
+	assert.Equal(t, deprecatedSuggestions[3].MessageArgs()[0], "Old")
+	assert.Equal(t, deprecatedSuggestions[4].MessageArgs()[0], "val")
+	assert.Equal(t, deprecatedSuggestions[5].MessageArgs()[0], "Bar")
+}