duktape/tests/api/test-get-set-top.c

/*===
*** test_1 (duk_safe_call)
test_1
--- top=0
top=0, idx=0, type 0 -> (null)
--- top=3
top=3, idx=0, type 5 -> foo
top=3, idx=1, type 5 -> bar
top=3, idx=2, type 5 -> quux
top=3, idx=3, type 0 -> (null)
--- top=5
top=5, idx=0, type 5 -> foo
top=5, idx=1, type 5 -> bar
top=5, idx=2, type 5 -> quux
top=5, idx=3, type 1 -> undefined
top=5, idx=4, type 1 -> undefined
top=5, idx=5, type 0 -> (null)
--- top=2
top=2, idx=0, type 5 -> foo
top=2, idx=1, type 5 -> bar
top=2, idx=2, type 0 -> (null)
--- top=0
top=0, idx=0, type 0 -> (null)
==> rc=0, result='undefined'
*** test_2 (duk_safe_call)
test_2
--- top=0
top=0, idx=0, type 0 -> (null)
--- top=3
top=3, idx=0, type 5 -> foo
top=3, idx=1, type 5 -> bar
top=3, idx=2, type 5 -> quux
top=3, idx=3, type 0 -> (null)
==> rc=1, result='Error: invalid stack index -4'
*** test_3 (duk_safe_call)
test_3
--- top=0
top=0, idx=0, type 0 -> (null)
--- top=3
top=3, idx=0, type 5 -> foo
top=3, idx=1, type 5 -> bar
top=3, idx=2, type 5 -> quux
top=3, idx=3, type 0 -> (null)
==> rc=1, result='Error: invalid stack index -2147483648'
*** test_4 (duk_safe_call)
test_4
--- top=0
top=0, idx=0, type 0 -> (null)
--- top=3
top=3, idx=0, type 5 -> foo
top=3, idx=1, type 5 -> bar
top=3, idx=2, type 5 -> quux
top=3, idx=3, type 0 -> (null)
==> rc=1, result='Error: invalid stack index 500'
*** test_5 (duk_safe_call)
test_5
--- top=0
top=0, idx=0, type 0 -> (null)
--- top=3
top=3, idx=0, type 5 -> foo
top=3, idx=1, type 5 -> bar
top=3, idx=2, type 5 -> quux
top=3, idx=3, type 0 -> (null)
duk_set_top for 500 ok
==> rc=0, result='undefined'
===*/

static void print_stack(duk_context *ctx) {
	duk_int_t t;
	duk_idx_t i, top;
	const char *str;

	top = duk_get_top(ctx);
	printf("--- top=%ld\n", (long) top);
	for (i = 0; i <= top; i++) {
		/* Go one over top intentionally */
		t = duk_get_type(ctx, i);  /* before coercion */
		if (i < top) {
			duk_to_string(ctx, i);
		}
		str = duk_get_string(ctx, i);
		printf("top=%ld, idx=%ld, type %d -> %s\n",
		       (long) top, (long) i, (int) t, (str != NULL ? str : "(null)"));
	}
}

static void prep(duk_context *ctx) {
	duk_set_top(ctx, 0);
	print_stack(ctx);
	duk_push_string(ctx, "foo");
	duk_push_string(ctx, "bar");
	duk_push_string(ctx, "quux");
	print_stack(ctx);
}

static duk_ret_t test_1(duk_context *ctx, void *udata) {
	(void) udata;

	printf("test_1\n");
	prep(ctx);

	/* extend with undefined */
	duk_set_top(ctx, 5);
	print_stack(ctx);

	/* chop, using a negative top value */
	duk_set_top(ctx, -3);   /* = duk_set_top(ctx, 2) */
	print_stack(ctx);

	/* to empty */
	duk_set_top(ctx, 0);
	print_stack(ctx);

	return 0;
}

static duk_ret_t test_2(duk_context *ctx, void *udata) {
	(void) udata;

	printf("test_2\n");
	prep(ctx);

	/* out of bounds negative top value */
	duk_set_top(ctx, -4);
	printf("duk_set_top for -4 ok\n");

	return 0;
}

static duk_ret_t test_3(duk_context *ctx, void *udata) {
	(void) udata;

	printf("test_3\n");
	prep(ctx);

	/* invalid top value */
	duk_set_top(ctx, DUK_INVALID_INDEX);
	printf("duk_set_top for DUK_INVALID_INDEX ok\n");

	return 0;
}

static duk_ret_t test_4(duk_context *ctx, void *udata) {
	(void) udata;

	printf("test_4\n");
	prep(ctx);

	/* positive top value is too high compared to "checked" stack size */
	duk_set_top(ctx, 500);
	printf("duk_set_top for 500 ok\n");

	return 0;
}

static duk_ret_t test_5(duk_context *ctx, void *udata) {
	(void) udata;

	printf("test_5\n");
	prep(ctx);

	/* by "checking" the stack, set to 500 works */
	duk_require_stack(ctx, 500);
	duk_set_top(ctx, 500);
	printf("duk_set_top for 500 ok\n");

	return 0;
}

void test(duk_context *ctx) {
	TEST_SAFE_CALL(test_1);
	TEST_SAFE_CALL(test_2);
	TEST_SAFE_CALL(test_3);
	TEST_SAFE_CALL(test_4);
	TEST_SAFE_CALL(test_5);
}