added tests

interpreter/tests/lox/constructor/arguments.lox

@@ -0,0 +1,11 @@
+class Foo {
+  init(a, b) {
+    print "init"; // expect: init
+    this.a = a;
+    this.b = b;
+  }
+}
+
+var foo = Foo(1, 2);
+print foo.a; // expect: 1
+print foo.b; // expect: 2

interpreter/tests/lox/constructor/call_init_early_return.lox

@@ -0,0 +1,11 @@
+class Foo {
+  init() {
+    print "init";
+    return;
+    print "nope";
+  }
+}
+
+var foo = Foo(); // expect: init
+print foo.init(); // expect: init
+// expect: Foo instance

interpreter/tests/lox/constructor/call_init_explicitly.lox

@@ -0,0 +1,15 @@
+class Foo {
+  init(arg) {
+    print "Foo.init(" + arg + ")";
+    this.field = "init";
+  }
+}
+
+var foo = Foo("one"); // expect: Foo.init(one)
+foo.field = "field";
+
+var foo2 = foo.init("two"); // expect: Foo.init(two)
+print foo2; // expect: Foo instance
+
+// Make sure init() doesn't create a fresh instance.
+print foo.field; // expect: init

interpreter/tests/lox/constructor/default.lox

@@ -0,0 +1,4 @@
+class Foo {}
+
+var foo = Foo();
+print foo; // expect: Foo instance

interpreter/tests/lox/constructor/default_arguments.lox

@@ -0,0 +1,3 @@
+class Foo {}
+
+var foo = Foo(1, 2, 3); // expect runtime error: Expected 0 arguments but got 3.

interpreter/tests/lox/constructor/early_return.lox

@@ -0,0 +1,10 @@
+class Foo {
+  init() {
+    print "init";
+    return;
+    print "nope";
+  }
+}
+
+var foo = Foo(); // expect: init
+print foo; // expect: Foo instance

interpreter/tests/lox/constructor/extra_arguments.lox

@@ -0,0 +1,8 @@
+class Foo {
+  init(a, b) {
+    this.a = a;
+    this.b = b;
+  }
+}
+
+var foo = Foo(1, 2, 3, 4); // expect runtime error: Expected 2 arguments but got 4.

interpreter/tests/lox/constructor/init_not_method.lox

@@ -0,0 +1,12 @@
+class Foo {
+  init(arg) {
+    print "Foo.init(" + arg + ")";
+    this.field = "init";
+  }
+}
+
+fun init() {
+  print "not initializer";
+}
+
+init(); // expect: not initializer

interpreter/tests/lox/constructor/missing_arguments.lox

@@ -0,0 +1,5 @@
+class Foo {
+  init(a, b) {}
+}
+
+var foo = Foo(1); // expect runtime error: Expected 2 arguments but got 1.

interpreter/tests/lox/constructor/return_in_nested_function.lox

@@ -0,0 +1,10 @@
+class Foo {
+  init() {
+    fun init() {
+      return "bar";
+    }
+    print init(); // expect: bar
+  }
+}
+
+print Foo(); // expect: Foo instance

interpreter/tests/lox/constructor/return_value.lox

@@ -0,0 +1,5 @@
+class Foo {
+  init() {
+    return "result"; // Error at 'return': Can't return a value from an initializer.
+  }
+}