Parenthesize new-expression callees when needed

tsc/internal/printer/printer.go

@@ -2593,8 +2593,9 @@ func (p *Printer) emitNewExpression(node *ast.NewExpression) {
 	state := p.enterNode(node.AsNode())
 	p.emitToken(ast.KindNewKeyword, node.Pos(), WriteKindKeyword, node.AsNode())
 	p.writeSpace()
-	if ast.SkipPartiallyEmittedExpressions(node.Expression).Kind == ast.KindCallExpression {
-		// Parenthesize `C()` inside of a NewExpression so it is treated as `new (C())` and not `new C()`
+	if hasUnparenthesizedCallAtStartOfMemberChain(node.Expression) {
+		// Parenthesize `C()` or `C().D` inside of a NewExpression so it is treated as `new (C())` or `new (C().D)`
+		// and not `new C()` or `new C().D`
 		p.emitExpression(node.Expression, ast.OperatorPrecedenceParentheses)
 	} else {
 		p.emitExpression(node.Expression, ast.OperatorPrecedenceMember)

tsc/internal/printer/utilities.go

@@ -622,6 +622,30 @@ func isNewExpressionWithoutArguments(node *ast.Node) bool {
 	return node.Kind == ast.KindNewExpression && node.ArgumentList() == nil
 }
 
+// Determines whether the expression of a NewExpression would be emitted with an unparenthesized CallExpression at the
+// start of its member chain, such as `C()` in `C().D`. Such an expression must be parenthesized when used as the
+// expression of a NewExpression, since `new C().D()` would be parsed as `(new C()).D()` rather than `new (C().D)()`.
+func hasUnparenthesizedCallAtStartOfMemberChain(node *ast.Expression) bool {
+	for {
+		node = ast.SkipPartiallyEmittedExpressions(node)
+		if ast.GetExpressionPrecedence(node) < ast.OperatorPrecedenceMember {
+			// Each expression in the member chain is emitted with member precedence, so this expression will already
+			// be parenthesized, which ends the member chain.
+			return false
+		}
+		switch node.Kind {
+		case ast.KindCallExpression:
+			return true
+		case ast.KindPropertyAccessExpression, ast.KindElementAccessExpression, ast.KindExpressionWithTypeArguments:
+			node = node.Expression()
+		case ast.KindTaggedTemplateExpression:
+			node = node.AsTaggedTemplateExpression().Tag
+		default:
+			return false
+		}
+	}
+}
+
 func isBinaryOperation(node *ast.Node, token ast.Kind) bool {
 	node = ast.SkipPartiallyEmittedExpressions(node)
 	return node.Kind == ast.KindBinaryExpression &&

tsc/testdata/baselines/reference/compiler/newExpressionCalleeParentheses.js

@@ -0,0 +1,60 @@
+//// [tests/cases/compiler/newExpressionCalleeParentheses.ts] ////
+
+//// [newExpressionCalleeParentheses.ts]
+declare function getPlugins(): any;
+declare function getPluginsGeneric<T>(): T;
+declare function getPluginsFactory(): <T>() => T;
+declare const obj: any;
+declare class Foo { [key: string]: any }
+
+// Parentheses are required when a call is at the start of the member chain of a `new` expression's target
+const a1 = new (getPlugins() as any).Linker();
+const a2 = new (getPlugins() satisfies any).Linker();
+const a3 = new (<any>getPlugins()).Linker();
+const a4 = new (getPlugins() as any)!.Linker();
+const a5 = new (getPlugins() as any)["Linker"]();
+const a6 = new (getPlugins() as any).ns.Linker();
+const a7 = new (getPlugins() as any).Linker;
+const a8 = new (getPlugins() as any)`tag`();
+const a9 = new (obj.getPlugins() as any).Linker();
+const a10 = new (getPlugins().ns as any).Linker();
+const a11 = new ((getPlugins() as any) as any).Linker();
+const a12 = new (getPluginsGeneric<any>() as any).Linker();
+const a13 = new (getPluginsFactory()<string> as any).Linker();
+const a14 = new (getPlugins() as any).Linker(new (getPlugins() as any).Options());
+
+// Parentheses are not required, or are already present
+const b1 = new (getPlugins() as any)();
+const b2 = new (getPlugins()).Linker();
+const b3 = new (new Foo() as any).Linker();
+const b4 = new (new Foo as any).Linker();
+const b5 = new (obj?.getPlugins() as any).Linker();
+const b6 = new (obj[getPlugins()] as any).Linker();
+const b7 = new (obj.ns as any).Linker();
+
+
+//// [newExpressionCalleeParentheses.js]
+"use strict";
+// Parentheses are required when a call is at the start of the member chain of a `new` expression's target
+const a1 = new (getPlugins().Linker)();
+const a2 = new (getPlugins().Linker)();
+const a3 = new (getPlugins().Linker)();
+const a4 = new (getPlugins().Linker)();
+const a5 = new (getPlugins()["Linker"])();
+const a6 = new (getPlugins().ns.Linker)();
+const a7 = new (getPlugins().Linker);
+const a8 = new (getPlugins() `tag`)();
+const a9 = new (obj.getPlugins().Linker)();
+const a10 = new (getPlugins().ns.Linker)();
+const a11 = new (getPlugins().Linker)();
+const a12 = new (getPluginsGeneric().Linker)();
+const a13 = new (getPluginsFactory().Linker)();
+const a14 = new (getPlugins().Linker)(new (getPlugins().Options)());
+// Parentheses are not required, or are already present
+const b1 = new (getPlugins())();
+const b2 = new (getPlugins()).Linker();
+const b3 = new new Foo().Linker();
+const b4 = new (new Foo).Linker();
+const b5 = new (obj?.getPlugins()).Linker();
+const b6 = new obj[getPlugins()].Linker();
+const b7 = new obj.ns.Linker();

tsc/testdata/baselines/reference/compiler/newExpressionCalleeParentheses.symbols

@@ -0,0 +1,111 @@
+//// [tests/cases/compiler/newExpressionCalleeParentheses.ts] ////
+
+=== newExpressionCalleeParentheses.ts ===
+declare function getPlugins(): any;
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+declare function getPluginsGeneric<T>(): T;
+>getPluginsGeneric : Symbol(getPluginsGeneric, Decl(newExpressionCalleeParentheses.ts, 0, 35))
+>T : Symbol(T, Decl(newExpressionCalleeParentheses.ts, 1, 35))
+>T : Symbol(T, Decl(newExpressionCalleeParentheses.ts, 1, 35))
+
+declare function getPluginsFactory(): <T>() => T;
+>getPluginsFactory : Symbol(getPluginsFactory, Decl(newExpressionCalleeParentheses.ts, 1, 43))
+>T : Symbol(T, Decl(newExpressionCalleeParentheses.ts, 2, 39))
+>T : Symbol(T, Decl(newExpressionCalleeParentheses.ts, 2, 39))
+
+declare const obj: any;
+>obj : Symbol(obj, Decl(newExpressionCalleeParentheses.ts, 3, 13))
+
+declare class Foo { [key: string]: any }
+>Foo : Symbol(Foo, Decl(newExpressionCalleeParentheses.ts, 3, 23))
+>key : Symbol(key, Decl(newExpressionCalleeParentheses.ts, 4, 21))
+
+// Parentheses are required when a call is at the start of the member chain of a `new` expression's target
+const a1 = new (getPlugins() as any).Linker();
+>a1 : Symbol(a1, Decl(newExpressionCalleeParentheses.ts, 7, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const a2 = new (getPlugins() satisfies any).Linker();
+>a2 : Symbol(a2, Decl(newExpressionCalleeParentheses.ts, 8, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const a3 = new (<any>getPlugins()).Linker();
+>a3 : Symbol(a3, Decl(newExpressionCalleeParentheses.ts, 9, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const a4 = new (getPlugins() as any)!.Linker();
+>a4 : Symbol(a4, Decl(newExpressionCalleeParentheses.ts, 10, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const a5 = new (getPlugins() as any)["Linker"]();
+>a5 : Symbol(a5, Decl(newExpressionCalleeParentheses.ts, 11, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const a6 = new (getPlugins() as any).ns.Linker();
+>a6 : Symbol(a6, Decl(newExpressionCalleeParentheses.ts, 12, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const a7 = new (getPlugins() as any).Linker;
+>a7 : Symbol(a7, Decl(newExpressionCalleeParentheses.ts, 13, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const a8 = new (getPlugins() as any)`tag`();
+>a8 : Symbol(a8, Decl(newExpressionCalleeParentheses.ts, 14, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const a9 = new (obj.getPlugins() as any).Linker();
+>a9 : Symbol(a9, Decl(newExpressionCalleeParentheses.ts, 15, 5))
+>obj : Symbol(obj, Decl(newExpressionCalleeParentheses.ts, 3, 13))
+
+const a10 = new (getPlugins().ns as any).Linker();
+>a10 : Symbol(a10, Decl(newExpressionCalleeParentheses.ts, 16, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const a11 = new ((getPlugins() as any) as any).Linker();
+>a11 : Symbol(a11, Decl(newExpressionCalleeParentheses.ts, 17, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const a12 = new (getPluginsGeneric<any>() as any).Linker();
+>a12 : Symbol(a12, Decl(newExpressionCalleeParentheses.ts, 18, 5))
+>getPluginsGeneric : Symbol(getPluginsGeneric, Decl(newExpressionCalleeParentheses.ts, 0, 35))
+
+const a13 = new (getPluginsFactory()<string> as any).Linker();
+>a13 : Symbol(a13, Decl(newExpressionCalleeParentheses.ts, 19, 5))
+>getPluginsFactory : Symbol(getPluginsFactory, Decl(newExpressionCalleeParentheses.ts, 1, 43))
+
+const a14 = new (getPlugins() as any).Linker(new (getPlugins() as any).Options());
+>a14 : Symbol(a14, Decl(newExpressionCalleeParentheses.ts, 20, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+// Parentheses are not required, or are already present
+const b1 = new (getPlugins() as any)();
+>b1 : Symbol(b1, Decl(newExpressionCalleeParentheses.ts, 23, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const b2 = new (getPlugins()).Linker();
+>b2 : Symbol(b2, Decl(newExpressionCalleeParentheses.ts, 24, 5))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const b3 = new (new Foo() as any).Linker();
+>b3 : Symbol(b3, Decl(newExpressionCalleeParentheses.ts, 25, 5))
+>Foo : Symbol(Foo, Decl(newExpressionCalleeParentheses.ts, 3, 23))
+
+const b4 = new (new Foo as any).Linker();
+>b4 : Symbol(b4, Decl(newExpressionCalleeParentheses.ts, 26, 5))
+>Foo : Symbol(Foo, Decl(newExpressionCalleeParentheses.ts, 3, 23))
+
+const b5 = new (obj?.getPlugins() as any).Linker();
+>b5 : Symbol(b5, Decl(newExpressionCalleeParentheses.ts, 27, 5))
+>obj : Symbol(obj, Decl(newExpressionCalleeParentheses.ts, 3, 13))
+
+const b6 = new (obj[getPlugins()] as any).Linker();
+>b6 : Symbol(b6, Decl(newExpressionCalleeParentheses.ts, 28, 5))
+>obj : Symbol(obj, Decl(newExpressionCalleeParentheses.ts, 3, 13))
+>getPlugins : Symbol(getPlugins, Decl(newExpressionCalleeParentheses.ts, 0, 0))
+
+const b7 = new (obj.ns as any).Linker();
+>b7 : Symbol(b7, Decl(newExpressionCalleeParentheses.ts, 29, 5))
+>obj : Symbol(obj, Decl(newExpressionCalleeParentheses.ts, 3, 13))
+