Add a test case related to spreading objects (#57642)

Author: Andarist

tests/baselines/reference/spreadObjectNoCircular1.symbols

@@ -0,0 +1,37 @@
+//// [tests/cases/compiler/spreadObjectNoCircular1.ts] ////
+
+=== spreadObjectNoCircular1.ts ===
+type Box = {
+>Box : Symbol(Box, Decl(spreadObjectNoCircular1.ts, 0, 0))
+
+  content?: Foo | Box;
+>content : Symbol(content, Decl(spreadObjectNoCircular1.ts, 0, 12))
+>Foo : Symbol(Foo, Decl(spreadObjectNoCircular1.ts, 4, 21))
+>Box : Symbol(Box, Decl(spreadObjectNoCircular1.ts, 0, 0))
+
+};
+
+declare const b: Box;
+>b : Symbol(b, Decl(spreadObjectNoCircular1.ts, 4, 13))
+>Box : Symbol(Box, Decl(spreadObjectNoCircular1.ts, 0, 0))
+
+class Foo {
+>Foo : Symbol(Foo, Decl(spreadObjectNoCircular1.ts, 4, 21))
+
+  get foo() {
+>foo : Symbol(Foo.foo, Decl(spreadObjectNoCircular1.ts, 6, 11))
+
+    return {
+      content: this as Foo | Box,
+>content : Symbol(content, Decl(spreadObjectNoCircular1.ts, 8, 12))
+>this : Symbol(Foo, Decl(spreadObjectNoCircular1.ts, 4, 21))
+>Foo : Symbol(Foo, Decl(spreadObjectNoCircular1.ts, 4, 21))
+>Box : Symbol(Box, Decl(spreadObjectNoCircular1.ts, 0, 0))
+
+      ...b,
+>b : Symbol(b, Decl(spreadObjectNoCircular1.ts, 4, 13))
+
+    };
+  }
+}
+

tests/baselines/reference/spreadObjectNoCircular1.types

@@ -0,0 +1,35 @@
+//// [tests/cases/compiler/spreadObjectNoCircular1.ts] ////
+
+=== spreadObjectNoCircular1.ts ===
+type Box = {
+>Box : { content?: Foo | Box | undefined; }
+
+  content?: Foo | Box;
+>content : Foo | Box | undefined
+
+};
+
+declare const b: Box;
+>b : Box
+
+class Foo {
+>Foo : Foo
+
+  get foo() {
+>foo : { content: Foo | Box; }
+
+    return {
+>{      content: this as Foo | Box,      ...b,    } : { content: Foo | Box; }
+
+      content: this as Foo | Box,
+>content : Foo | Box
+>this as Foo | Box : Foo | Box
+>this : this
+
+      ...b,
+>b : Box
+
+    };
+  }
+}
+

tests/cases/compiler/spreadObjectNoCircular1.ts

@@ -0,0 +1,17 @@
+// @strict: true
+// @noEmit: true
+
+type Box = {
+  content?: Foo | Box;
+};
+
+declare const b: Box;
+
+class Foo {
+  get foo() {
+    return {
+      content: this as Foo | Box,
+      ...b,
+    };
+  }
+}