added tests

interpreter/tests/lox/class/empty.lox

@@ -0,0 +1,3 @@
+class Foo {}
+
+print Foo; // expect: Foo

interpreter/tests/lox/class/inherit_self.lox

@@ -0,0 +1 @@
+class Foo < Foo {} // Error at 'Foo': A class can't inherit from itself.

interpreter/tests/lox/class/inherited_method.lox

@@ -0,0 +1,22 @@
+class Foo {
+  inFoo() {
+    print "in foo";
+  }
+}
+
+class Bar < Foo {
+  inBar() {
+    print "in bar";
+  }
+}
+
+class Baz < Bar {
+  inBaz() {
+    print "in baz";
+  }
+}
+
+var baz = Baz();
+baz.inFoo(); // expect: in foo
+baz.inBar(); // expect: in bar
+baz.inBaz(); // expect: in baz

interpreter/tests/lox/class/local_inherit_other.lox

@@ -0,0 +1,8 @@
+class A {}
+
+fun f() {
+  class B < A {}
+  return B;
+}
+
+print f(); // expect: B

interpreter/tests/lox/class/local_inherit_self.lox

@@ -0,0 +1,4 @@
+{
+  class Foo < Foo {} // Error at 'Foo': A class can't inherit from itself.
+}
+// [c line 5] Error at end: Expect '}' after block.

interpreter/tests/lox/class/local_reference_self.lox

@@ -0,0 +1,9 @@
+{
+  class Foo {
+    returnSelf() {
+      return Foo;
+    }
+  }
+
+  print Foo().returnSelf(); // expect: Foo
+}

interpreter/tests/lox/class/reference_self.lox

@@ -0,0 +1,7 @@
+class Foo {
+  returnSelf() {
+    return Foo;
+  }
+}
+
+print Foo().returnSelf(); // expect: Foo