Add regression test

Author: ahejlsberg

tests/baselines/reference/signatureInstantiationWithRecursiveConstraints.js

@@ -0,0 +1,30 @@
+//// [signatureInstantiationWithRecursiveConstraints.ts]
+// Repro from #17148
+
+class Foo {
+  myFunc<T extends Foo>(arg: T) {}
+}
+
+class Bar {
+  myFunc<T extends Bar>(arg: T) {}
+}
+
+const myVar: Foo = new Bar();
+
+
+//// [signatureInstantiationWithRecursiveConstraints.js]
+"use strict";
+// Repro from #17148
+var Foo = (function () {
+    function Foo() {
+    }
+    Foo.prototype.myFunc = function (arg) { };
+    return Foo;
+}());
+var Bar = (function () {
+    function Bar() {
+    }
+    Bar.prototype.myFunc = function (arg) { };
+    return Bar;
+}());
+var myVar = new Bar();

tests/baselines/reference/signatureInstantiationWithRecursiveConstraints.symbols

@@ -0,0 +1,30 @@
+=== tests/cases/compiler/signatureInstantiationWithRecursiveConstraints.ts ===
+// Repro from #17148
+
+class Foo {
+>Foo : Symbol(Foo, Decl(signatureInstantiationWithRecursiveConstraints.ts, 0, 0))
+
+  myFunc<T extends Foo>(arg: T) {}
+>myFunc : Symbol(Foo.myFunc, Decl(signatureInstantiationWithRecursiveConstraints.ts, 2, 11))
+>T : Symbol(T, Decl(signatureInstantiationWithRecursiveConstraints.ts, 3, 9))
+>Foo : Symbol(Foo, Decl(signatureInstantiationWithRecursiveConstraints.ts, 0, 0))
+>arg : Symbol(arg, Decl(signatureInstantiationWithRecursiveConstraints.ts, 3, 24))
+>T : Symbol(T, Decl(signatureInstantiationWithRecursiveConstraints.ts, 3, 9))
+}
+
+class Bar {
+>Bar : Symbol(Bar, Decl(signatureInstantiationWithRecursiveConstraints.ts, 4, 1))
+
+  myFunc<T extends Bar>(arg: T) {}
+>myFunc : Symbol(Bar.myFunc, Decl(signatureInstantiationWithRecursiveConstraints.ts, 6, 11))
+>T : Symbol(T, Decl(signatureInstantiationWithRecursiveConstraints.ts, 7, 9))
+>Bar : Symbol(Bar, Decl(signatureInstantiationWithRecursiveConstraints.ts, 4, 1))
+>arg : Symbol(arg, Decl(signatureInstantiationWithRecursiveConstraints.ts, 7, 24))
+>T : Symbol(T, Decl(signatureInstantiationWithRecursiveConstraints.ts, 7, 9))
+}
+
+const myVar: Foo = new Bar();
+>myVar : Symbol(myVar, Decl(signatureInstantiationWithRecursiveConstraints.ts, 10, 5))
+>Foo : Symbol(Foo, Decl(signatureInstantiationWithRecursiveConstraints.ts, 0, 0))
+>Bar : Symbol(Bar, Decl(signatureInstantiationWithRecursiveConstraints.ts, 4, 1))
+

tests/baselines/reference/signatureInstantiationWithRecursiveConstraints.types

@@ -0,0 +1,31 @@
+=== tests/cases/compiler/signatureInstantiationWithRecursiveConstraints.ts ===
+// Repro from #17148
+
+class Foo {
+>Foo : Foo
+
+  myFunc<T extends Foo>(arg: T) {}
+>myFunc : <T extends Foo>(arg: T) => void
+>T : T
+>Foo : Foo
+>arg : T
+>T : T
+}
+
+class Bar {
+>Bar : Bar
+
+  myFunc<T extends Bar>(arg: T) {}
+>myFunc : <T extends Bar>(arg: T) => void
+>T : T
+>Bar : Bar
+>arg : T
+>T : T
+}
+
+const myVar: Foo = new Bar();
+>myVar : Foo
+>Foo : Foo
+>new Bar() : Bar
+>Bar : typeof Bar
+

tests/cases/compiler/signatureInstantiationWithRecursiveConstraints.ts

@@ -0,0 +1,13 @@
+// @strict: true
+
+// Repro from #17148
+
+class Foo {
+  myFunc<T extends Foo>(arg: T) {}
+}
+
+class Bar {
+  myFunc<T extends Bar>(arg: T) {}
+}
+
+const myVar: Foo = new Bar();