add def for add,mul,draw value

test/test_value.py

@@ -0,0 +1,58 @@
+from micrograd.engine import Value
+
+
+def test_value_init():
+    v = Value(1)
+    assert v.data == 1
+
+
+def test_value_repr():
+    v = Value(2.0)
+    assert "Value(data=2.0)" == repr(v)
+
+
+def test_value_add():
+    v1 = Value(2.0)
+    v2 = Value(4.0)
+    assert (v1 + v2).data == 6.0
+    assert "Value(data=6.0)" == repr(v1 + v2)
+
+
+def test_value_sub():
+    v1 = Value(2.0)
+    v2 = Value(4.0)
+    assert (v1 - v2).data == -2.0
+    assert "Value(data=-2.0)" == repr(v1 - v2)
+
+
+def test_value_mul():
+    v1 = Value(2.0)
+    v2 = Value(4.0)
+    v3 = Value(-1.0)
+    assert (v1 * v2).data == 8.0
+    assert (v1 * v3).data == -2.0
+
+
+def test_value_mul_add():
+    v1 = Value(2.0)
+    v2 = Value(4.0)
+    v3 = Value(-1.0)
+    assert ((v1 * v3) + v2).data == 2.0
+
+
+def test_children():
+    v1 = Value(2.0)
+    v2 = Value(4.0)
+    out = v1 * v2
+    assert len(out._prev) == 2
+    assert v1 in out._prev
+    assert v2 in out._prev
+
+
+def test_operations():
+    v1 = Value(2.0)
+    v2 = Value(4.0)
+    mul = v1 * v2
+    add = v1 + v2
+    assert mul._op == '*'
+    assert add._op == '+'