added tests

interpreter/tests/lox/if/class_in_else.lox

@@ -0,0 +1,2 @@
+// [line 2] Error at 'class': Expect expression.
+if (true) "ok"; else class Foo {}

interpreter/tests/lox/if/class_in_then.lox

@@ -0,0 +1,2 @@
+// [line 2] Error at 'class': Expect expression.
+if (true) class Foo {}

interpreter/tests/lox/if/dangling_else.lox

@@ -0,0 +1,3 @@
+// A dangling else binds to the right-most if.
+if (true) if (false) print "bad"; else print "good"; // expect: good
+if (false) if (true) print "bad"; else print "bad";

interpreter/tests/lox/if/else.lox

@@ -0,0 +1,6 @@
+// Evaluate the 'else' expression if the condition is false.
+if (true) print "good"; else print "bad"; // expect: good
+if (false) print "bad"; else print "good"; // expect: good
+
+// Allow block body.
+if (false) nil; else { print "block"; } // expect: block

interpreter/tests/lox/if/fun_in_else.lox

@@ -0,0 +1,2 @@
+// [line 2] Error at 'fun': Expect expression.
+if (true) "ok"; else fun foo() {}

interpreter/tests/lox/if/fun_in_then.lox

@@ -0,0 +1,2 @@
+// [line 2] Error at 'fun': Expect expression.
+if (true) fun foo() {}

interpreter/tests/lox/if/if.lox

@@ -0,0 +1,10 @@
+// Evaluate the 'then' expression if the condition is true.
+if (true) print "good"; // expect: good
+if (false) print "bad";
+
+// Allow block body.
+if (true) { print "block"; } // expect: block
+
+// Assignment in if condition.
+var a = false;
+if (a = true) print a; // expect: true

interpreter/tests/lox/if/truth.lox

@@ -0,0 +1,8 @@
+// False and nil are false.
+if (false) print "bad"; else print "false"; // expect: false
+if (nil) print "bad"; else print "nil"; // expect: nil
+
+// Everything else is true.
+if (true) print true; // expect: true
+if (0) print 0; // expect: 0
+if ("") print "empty"; // expect: empty

interpreter/tests/lox/if/var_in_else.lox

@@ -0,0 +1,2 @@
+// [line 2] Error at 'var': Expect expression.
+if (true) "ok"; else var foo;

interpreter/tests/lox/if/var_in_then.lox

@@ -0,0 +1,2 @@
+// [line 2] Error at 'var': Expect expression.
+if (true) var foo;