Leverage existing function for choosing spread validity (#21564)

src/compiler/checker.ts

@@ -17603,7 +17603,7 @@ namespace ts {
                         const anonymousSymbol = createSymbol(SymbolFlags.TypeLiteral, InternalSymbolName.Type);
                         const defaultContainingObject = createAnonymousType(anonymousSymbol, memberTable, emptyArray, emptyArray, /*stringIndexInfo*/ undefined, /*numberIndexInfo*/ undefined);
                         anonymousSymbol.type = defaultContainingObject;
-                        synthType.syntheticType = (type.flags & TypeFlags.StructuredType && type.symbol.flags & (SymbolFlags.Module | SymbolFlags.Variable)) ? getSpreadType(type, defaultContainingObject, anonymousSymbol, /*propegatedFlags*/ 0) : defaultContainingObject;
+                        synthType.syntheticType = isValidSpreadType(type) ? getSpreadType(type, defaultContainingObject, anonymousSymbol, /*propegatedFlags*/ 0) : defaultContainingObject;
                     }
                     else {
                         synthType.syntheticType = type;

tests/baselines/reference/esModuleIntersectionCrash.js

@@ -0,0 +1,27 @@
+//// [tests/cases/compiler/esModuleIntersectionCrash.ts] ////
+
+//// [mod.d.ts]
+export = modObj;
+declare const modObj: modObj.A & modObj.B;
+declare namespace modObj {
+    interface A { (): void; a: string; }
+    interface B { (x: string): void; b: string; }
+}
+//// [idx.ts]
+import * as mod from "./mod";
+mod.a;
+mod.b;
+
+//// [idx.js]
+"use strict";
+var __importStar = (this && this.__importStar) || function (mod) {
+    if (mod && mod.__esModule) return mod;
+    var result = {};
+    if (mod != null) for (var k in mod) if (Object.hasOwnProperty.call(mod, k)) result[k] = mod[k];
+    result["default"] = mod;
+    return result;
+}
+exports.__esModule = true;
+var mod = __importStar(require("./mod"));
+mod.a;
+mod.b;

tests/baselines/reference/esModuleIntersectionCrash.symbols

@@ -0,0 +1,37 @@
+=== tests/cases/compiler/mod.d.ts ===
+export = modObj;
+>modObj : Symbol(modObj, Decl(mod.d.ts, 1, 13), Decl(mod.d.ts, 1, 42))
+
+declare const modObj: modObj.A & modObj.B;
+>modObj : Symbol(modObj, Decl(mod.d.ts, 1, 13), Decl(mod.d.ts, 1, 42))
+>modObj : Symbol(modObj, Decl(mod.d.ts, 1, 13), Decl(mod.d.ts, 1, 42))
+>A : Symbol(modObj.A, Decl(mod.d.ts, 2, 26))
+>modObj : Symbol(modObj, Decl(mod.d.ts, 1, 13), Decl(mod.d.ts, 1, 42))
+>B : Symbol(modObj.B, Decl(mod.d.ts, 3, 40))
+
+declare namespace modObj {
+>modObj : Symbol(modObj, Decl(mod.d.ts, 1, 13), Decl(mod.d.ts, 1, 42))
+
+    interface A { (): void; a: string; }
+>A : Symbol(A, Decl(mod.d.ts, 2, 26))
+>a : Symbol(A.a, Decl(mod.d.ts, 3, 27))
+
+    interface B { (x: string): void; b: string; }
+>B : Symbol(B, Decl(mod.d.ts, 3, 40))
+>x : Symbol(x, Decl(mod.d.ts, 4, 19))
+>b : Symbol(B.b, Decl(mod.d.ts, 4, 36))
+}
+=== tests/cases/compiler/idx.ts ===
+import * as mod from "./mod";
+>mod : Symbol(mod, Decl(idx.ts, 0, 6))
+
+mod.a;
+>mod.a : Symbol(mod.A.a, Decl(mod.d.ts, 3, 27))
+>mod : Symbol(mod, Decl(idx.ts, 0, 6))
+>a : Symbol(mod.A.a, Decl(mod.d.ts, 3, 27))
+
+mod.b;
+>mod.b : Symbol(mod.B.b, Decl(mod.d.ts, 4, 36))
+>mod : Symbol(mod, Decl(idx.ts, 0, 6))
+>b : Symbol(mod.B.b, Decl(mod.d.ts, 4, 36))
+

tests/baselines/reference/esModuleIntersectionCrash.types

@@ -0,0 +1,37 @@
+=== tests/cases/compiler/mod.d.ts ===
+export = modObj;
+>modObj : modObj.A & modObj.B
+
+declare const modObj: modObj.A & modObj.B;
+>modObj : modObj.A & modObj.B
+>modObj : any
+>A : modObj.A
+>modObj : any
+>B : modObj.B
+
+declare namespace modObj {
+>modObj : A & B
+
+    interface A { (): void; a: string; }
+>A : A
+>a : string
+
+    interface B { (x: string): void; b: string; }
+>B : B
+>x : string
+>b : string
+}
+=== tests/cases/compiler/idx.ts ===
+import * as mod from "./mod";
+>mod : { default: mod.A & mod.B; a: string; b: string; }
+
+mod.a;
+>mod.a : string
+>mod : { default: mod.A & mod.B; a: string; b: string; }
+>a : string
+
+mod.b;
+>mod.b : string
+>mod : { default: mod.A & mod.B; a: string; b: string; }
+>b : string
+

tests/cases/compiler/esModuleIntersectionCrash.ts

@@ -0,0 +1,12 @@
+// @esModuleInterop: true
+// @filename: mod.d.ts
+export = modObj;
+declare const modObj: modObj.A & modObj.B;
+declare namespace modObj {
+    interface A { (): void; a: string; }
+    interface B { (x: string): void; b: string; }
+}
+// @filename: idx.ts
+import * as mod from "./mod";
+mod.a;
+mod.b;