Add pwndbg.lib.cache test (#1691)

tests/gdb-tests/tests/test_cache.py

@@ -0,0 +1,68 @@
+import tests
+from pwndbg.lib import cache
+
+BINARY = tests.binaries.get("reference-binary.out")
+
+
+def test_cache_single_value(start_binary):
+    x = 0
+
+    @cache.cache_until("stop")
+    def foo():
+        nonlocal x
+        x += 1
+        # Typically its bad idea to cache a non-local/global variable
+        # but we need this for testing purposes :)
+        return x
+
+    assert foo() == x == 1
+
+    # The function result should now be pulled from cache
+    # so that `x` should not change as well
+    assert foo() == x == 1
+
+    foo.cache.clear()
+
+    assert foo() == x == 2
+    assert foo() == x == 2
+
+    # Check if cache is properly cleared on a stop event
+    start_binary(BINARY)
+    assert foo() == x == 3
+    assert foo() == x == 3
+
+
+def test_cache_args_kwargs_properly(start_binary):
+    x = 0
+
+    @cache.cache_until("stop")
+    def foo(arg0, *args, **kwargs):
+        nonlocal x
+        x += 1
+
+        # Typically its bad idea to cache a non-local/global variable
+        # but we need this for testing purposes :)
+        return x, arg0, args, kwargs
+
+    assert foo("abc") == (1, "abc", (), {}) and x == 1
+    assert foo("abc") == (1, "abc", (), {}) and x == 1
+
+    assert foo(100, 200) == (2, 100, (200,), {}) and x == 2
+    assert foo(100, 200) == (2, 100, (200,), {}) and x == 2
+
+    assert foo("abc") == (1, "abc", (), {}) and x == 2
+    assert foo(100, 200) == (2, 100, (200,), {}) and x == 2
+
+    foo.cache.clear()
+
+    assert foo("abc") == (3, "abc", (), {}) and x == 3
+    assert foo("abc") == (3, "abc", (), {}) and x == 3
+
+    assert foo(100, 200) == (4, 100, (200,), {}) and x == 4
+    assert foo(100, 200) == (4, 100, (200,), {}) and x == 4
+
+    # Check if cache is properly cleared on a stop event
+    start_binary(BINARY)
+
+    assert foo("abc") == (5, "abc", (), {}) and x == 5
+    assert foo(100, 200) == (6, 100, (200,), {}) and x == 6