fix: Fix nil pointer panic in getLateBoundSymbol under --noCheck

tsc/internal/binder/binder.go

@@ -1064,6 +1064,12 @@ func (b *Binder) bindDeferredExpandoAssignment(node *ast.Node) {
 	if symbol = getInitializerSymbol(symbol); symbol != nil {
 		if ast.HasDynamicName(node) {
 			b.bindAnonymousDeclaration(node, ast.SymbolFlagsProperty|ast.SymbolFlagsAssignment, ast.InternalSymbolNameComputed)
+			// Point the anonymous computed assignment at the expando host. For top-level
+			// scripts, bindAnonymousDeclaration would otherwise set parent to a nil
+			// SourceFile symbol, which breaks getLateBoundSymbol under --noCheck.
+			if declSym := node.Symbol(); declSym != nil {
+				declSym.SetParent(symbol)
+			}
 			b.addLateBoundAssignmentDeclarationToSymbol(node, symbol)
 		} else {
 			// We declare expandos only when there are no non-expando declarations for that name.

tsc/internal/checker/checker.go

@@ -14687,7 +14687,10 @@ func (c *Checker) getLateBoundSymbol(symbol *ast.Symbol) *ast.Symbol {
 	if links.lateSymbol == nil && core.Some(symbol.Declarations(), c.hasLateBindableName) {
 		// force late binding of members/exports. This will set the late-bound symbol
 		parent := c.getMergedSymbol(symbol.Parent())
-		if core.Some(symbol.Declarations(), ast.HasStaticModifier) {
+		// Function/namespace expandos are stored on exports (see AssignmentDeclaration),
+		// not members. BinaryExpression declarations never have a static modifier, so
+		// Assignment is the signal to resolve exports.
+		if core.Some(symbol.Declarations(), ast.HasStaticModifier) || symbol.Flags()&ast.SymbolFlagsAssignment != 0 {
 			c.getExportsOfSymbol(parent)
 		} else {
 			c.getMembersOfSymbol(parent)

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

@@ -0,0 +1,16 @@
+//// [tests/cases/compiler/noCheckExpandoElementAccessAssignment.ts] ////
+
+//// [noCheckExpandoElementAccessAssignment.ts]
+const k = "bar";
+foo[k] = 1;
+function foo() {}
+
+
+
+
+//// [noCheckExpandoElementAccessAssignment.d.ts]
+declare const k = "bar";
+declare function foo(): void;
+declare namespace foo {
+    var bar: number;
+}

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

@@ -0,0 +1,13 @@
+//// [tests/cases/compiler/noCheckExpandoElementAccessAssignment.ts] ////
+
+=== noCheckExpandoElementAccessAssignment.ts ===
+const k = "bar";
+>k : Symbol(k, Decl(noCheckExpandoElementAccessAssignment.ts, 0, 5))
+
+foo[k] = 1;
+>foo : Symbol(foo, Decl(noCheckExpandoElementAccessAssignment.ts, 1, 11))
+>k : Symbol(k, Decl(noCheckExpandoElementAccessAssignment.ts, 0, 5))
+
+function foo() {}
+>foo : Symbol(foo, Decl(noCheckExpandoElementAccessAssignment.ts, 1, 11))
+

tsc/testdata/baselines/reference/compiler/noCheckExpandoElementAccessAssignment.types

@@ -0,0 +1,17 @@
+//// [tests/cases/compiler/noCheckExpandoElementAccessAssignment.ts] ////
+
+=== noCheckExpandoElementAccessAssignment.ts ===
+const k = "bar";
+>k : "bar"
+>"bar" : "bar"
+
+foo[k] = 1;
+>foo[k] = 1 : 1
+>foo[k] : number
+>foo : { (): void; bar: number; }
+>k : "bar"
+>1 : 1
+
+function foo() {}
+>foo : { (): void; bar: number; }
+

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

@@ -0,0 +1,16 @@
+//// [tests/cases/compiler/noCheckExpandoElementAccessAssignmentInitializer.ts] ////
+
+//// [noCheckExpandoElementAccessAssignmentInitializer.ts]
+const k = "bar";
+const foo = () => {};
+foo[k] = 1;
+
+
+
+
+//// [noCheckExpandoElementAccessAssignmentInitializer.d.ts]
+declare const k = "bar";
+declare function foo(): void;
+declare namespace foo {
+    var bar: number;
+}

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

@@ -0,0 +1,13 @@
+//// [tests/cases/compiler/noCheckExpandoElementAccessAssignmentInitializer.ts] ////
+
+=== noCheckExpandoElementAccessAssignmentInitializer.ts ===
+const k = "bar";
+>k : Symbol(k, Decl(noCheckExpandoElementAccessAssignmentInitializer.ts, 0, 5))
+
+const foo = () => {};
+>foo : Symbol(foo, Decl(noCheckExpandoElementAccessAssignmentInitializer.ts, 1, 5))
+
+foo[k] = 1;
+>foo : Symbol(foo, Decl(noCheckExpandoElementAccessAssignmentInitializer.ts, 1, 5))
+>k : Symbol(k, Decl(noCheckExpandoElementAccessAssignmentInitializer.ts, 0, 5))
+

tsc/testdata/baselines/reference/compiler/noCheckExpandoElementAccessAssignmentInitializer.types

@@ -0,0 +1,18 @@
+//// [tests/cases/compiler/noCheckExpandoElementAccessAssignmentInitializer.ts] ////
+
+=== noCheckExpandoElementAccessAssignmentInitializer.ts ===
+const k = "bar";
+>k : "bar"
+>"bar" : "bar"
+
+const foo = () => {};
+>foo : { (): void; bar: number; }
+>() => {} : { (): void; bar: number; }
+
+foo[k] = 1;
+>foo[k] = 1 : 1
+>foo[k] : number
+>foo : { (): void; bar: number; }
+>k : "bar"
+>1 : 1
+

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

@@ -0,0 +1,15 @@
+//// [tests/cases/compiler/noCheckExpandoElementAccessAssignmentModule.ts] ////
+
+//// [noCheckExpandoElementAccessAssignmentModule.ts]
+const k = "bar";
+export function foo() {}
+foo[k] = 1;
+
+
+
+
+//// [noCheckExpandoElementAccessAssignmentModule.d.ts]
+export declare function foo(): void;
+export declare namespace foo {
+    var bar: number;
+}

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

@@ -0,0 +1,13 @@
+//// [tests/cases/compiler/noCheckExpandoElementAccessAssignmentModule.ts] ////
+
+=== noCheckExpandoElementAccessAssignmentModule.ts ===
+const k = "bar";
+>k : Symbol(k, Decl(noCheckExpandoElementAccessAssignmentModule.ts, 0, 5))
+
+export function foo() {}
+>foo : Symbol(foo, Decl(noCheckExpandoElementAccessAssignmentModule.ts, 0, 16))
+
+foo[k] = 1;
+>foo : Symbol(foo, Decl(noCheckExpandoElementAccessAssignmentModule.ts, 0, 16))
+>k : Symbol(k, Decl(noCheckExpandoElementAccessAssignmentModule.ts, 0, 5))
+

tsc/testdata/baselines/reference/compiler/noCheckExpandoElementAccessAssignmentModule.types

@@ -0,0 +1,17 @@
+//// [tests/cases/compiler/noCheckExpandoElementAccessAssignmentModule.ts] ////
+
+=== noCheckExpandoElementAccessAssignmentModule.ts ===
+const k = "bar";
+>k : "bar"
+>"bar" : "bar"
+
+export function foo() {}
+>foo : { (): void; bar: number; }
+
+foo[k] = 1;
+>foo[k] = 1 : 1
+>foo[k] : number
+>foo : { (): void; bar: number; }
+>k : "bar"
+>1 : 1
+

tsc/testdata/tests/cases/compiler/noCheckExpandoElementAccessAssignment.ts

@@ -0,0 +1,8 @@
+// @target: es2015
+// @noCheck: true
+// @emitDeclarationOnly: true
+// @declaration: true
+
+const k = "bar";
+foo[k] = 1;
+function foo() {}

tsc/testdata/tests/cases/compiler/noCheckExpandoElementAccessAssignmentInitializer.ts

@@ -0,0 +1,8 @@
+// @target: es2015
+// @noCheck: true
+// @emitDeclarationOnly: true
+// @declaration: true
+
+const k = "bar";
+const foo = () => {};
+foo[k] = 1;

tsc/testdata/tests/cases/compiler/noCheckExpandoElementAccessAssignmentModule.ts

@@ -0,0 +1,8 @@
+// @target: es2015
+// @noCheck: true
+// @emitDeclarationOnly: true
+// @declaration: true
+
+const k = "bar";
+export function foo() {}
+foo[k] = 1;