feat: add test programs for variable resolution and scoping rules

Author: ryan-gang

test_programs/r1/1.lox

@@ -1,3 +1,13 @@
 ---
 expected_error_type: none
 ---
+var a = "outer";
+{
+  fun foo() {
+    print a;
+  }
+
+  foo(); // expect: outer
+  var a = "inner";
+  foo(); // expect: outer
+}

test_programs/r1/2.lox

@@ -1,3 +1,18 @@
 ---
 expected_error_type: none
 ---
+fun global() {
+  print "global";
+}
+
+{
+  fun f() {
+    global();
+  }
+
+  f();
+  fun global() {
+    print "local";
+  }
+  f();
+}

test_programs/r1/3.lox

@@ -1,3 +1,23 @@
 ---
 expected_error_type: none
 ---
+// Multiple Nested Functions with Shadowing
+var x = "global";
+
+fun outer() {
+  var x = "outer";
+
+  fun middle() {
+    fun inner() {
+      print x; // Should capture "outer", not "global" or "inner"
+    }
+
+    inner();
+    var x = "middle";
+    inner(); // Should still print "outer"
+  }
+
+  middle();
+}
+
+outer();

test_programs/r1/4.lox

@@ -1,3 +1,22 @@
 ---
 expected_error_type: none
 ---
+// Function Returning a Function
+var count = 0;
+
+{
+  fun makeCounter() {
+    fun counter() {
+      count = count + 1;
+      print count;
+    }
+    return counter;
+  }
+
+  var counter1 = makeCounter();
+  counter1(); // Should print 1
+  counter1(); // Should print 2
+
+  var count = 0;
+  counter1(); // Should print 3
+}

test_programs/r4/1.lox

@@ -1,3 +1,6 @@
 ---
 expected_error_type: none
 ---
+var a = "value";
+var a = a;
+print a; // expect: value

test_programs/r4/2.lox

@@ -1,3 +1,7 @@
 ---
 expected_error_type: none
 ---
+var a = "outer";
+{
+  var a = a; // Error at 'a': Can't read local variable in its own initializer.
+}

test_programs/r6/1.lox

@@ -1,3 +1,8 @@
 ---
 expected_error_type: none
 ---
+if (false) {
+  print notDefined;
+}
+
+print "ok"; // expect: ok

test_programs/r6/2.lox

@@ -1,3 +1,6 @@
 ---
-expected_error_type: none
+expected_error_type: compile
 ---
+print a; // expect: compile error
+var a = "value";
+print a; // expect: value

test_programs/r7/1.lox

@@ -1,3 +1,7 @@
 ---
-expected_error_type: none
+expected_error_type: compile
 ---
+{
+  var a = "value";
+  var a = "other"; // Error at 'a': Already a variable with this name in this scope.
+}

test_programs/r7/2.lox

@@ -1,3 +1,6 @@
 ---
-expected_error_type: none
+expected_error_type: compile
 ---
+fun foo(a) {
+  var a; // Error at 'a': Already a variable with this name in this scope.
+}