Test package cached properties (#1977)

* Wrote a test case for cached_properties of the 'package' module

Signed-off-by: Harmouch101 <[email protected]>

* vi test_cache_utils.py

Signed-off-by: Harmouch101 <[email protected]>

* add newsfragment

Co-authored-by: Marc Garreau <[email protected]>

docs/contracts.rst

@@ -242,6 +242,7 @@ Each Contract Factory exposes the following methods.
         '0x4c0883a69102937d6231471b5dbb6204fe5129617082792ae468d01a3f362318'
 
 .. py:classmethod:: Contract.constructor(*args, **kwargs).estimateGas(transaction=None, block_identifier=None)
+    :noindex:
 
     Estimate gas for constructing and deploying the contract.
 
@@ -264,6 +265,7 @@ Each Contract Factory exposes the following methods.
         12563
 
 .. py:classmethod:: Contract.constructor(*args, **kwargs).buildTransaction(transaction=None)
+    :noindex:
 
     Construct the contract deploy transaction bytecode data.
 
@@ -945,6 +947,7 @@ For example:
 .. _processReceipt:
 
 .. py:method:: ContractEvents.myEvent(*args, **kwargs).processReceipt(transaction_receipt, errors=WARN)
+   :noindex:
 
    Extracts the pertinent logs from a transaction receipt.
 

docs/ethpm.rst

@@ -72,6 +72,7 @@ Methods
 Each ``Package`` exposes the following methods.
 
 .. autoclass:: ethpm.Package
+   :noindex:
    :members: from_file, from_uri, update_w3, get_contract_factory, get_contract_instance
 
 

ethpm/_utils/cache.py

@@ -1,4 +1,3 @@
-import functools
 from typing import (
     Any,
     Callable,
@@ -15,10 +14,9 @@ class cached_property:
     """
 
     def __init__(self, func: Callable[..., Any], name: str = None) -> None:
-        self.func = func
-        self.name = name or func.__name__
-        # type ignored b/c self is 'cached_property' but expects 'Callable[..., Any]'
-        functools.update_wrapper(self, func)  # type: ignore
+        self.wrapped_func = func
+        self.name = name
+        self.__doc__ = getattr(func, '__doc__')
 
     def __get__(self, instance: Any, cls: Any = None) -> Any:
         """
@@ -30,3 +28,17 @@ def __get__(self, instance: Any, cls: Any = None) -> Any:
             return self
         res = instance.__dict__[self.name] = self.func(instance)
         return res
+
+    def __set_name__(self, cls: Any = None, name: str = None) -> None:
+        """
+        The function is called at the time the cls class is created.
+        The descriptor would be assigned to name.
+        """
+        if self.name is None:
+            self.name = name
+            self.func = self.wrapped_func
+        if name != self.name:
+            raise TypeError(
+                "Unable to assign cached_property for two different names "
+                f"(%{self.name} and {name})."
+            )

newsfragments/1977.bugfix.rst

@@ -0,0 +1 @@
+Test ethpm caching + bump Sphinx version.

setup.py

@@ -24,7 +24,7 @@
         "py-geth>=2.4.0,<3",
         "py-solc>=0.4.0",
         "pytest>=4.4.0,<5.0.0",
-        "sphinx>=2.4.4,<3",
+        "sphinx>=3.0,<4",
         "sphinx_rtd_theme>=0.1.9",
         "toposort>=1.4",
         "towncrier>=19.2.0,<20",

tests/ethpm/_utils/test_cache_utils.py

@@ -0,0 +1,20 @@
+import random
+
+from ethpm._utils.cache import (
+    cached_property,
+)
+
+
+def test_cached_property():
+    class FOO:
+        def __int__(self):
+            pass
+
+        @cached_property
+        def generate_number(self):
+            return random.random()
+
+    foo = FOO()
+    foo_number = foo.generate_number
+    foo_cached_number = foo.generate_number
+    assert foo_number == foo_cached_number

tests/ethpm/test_package.py

@@ -87,3 +87,27 @@ def test_package_object_properties(safe_math_package):
     assert safe_math_package.uri is None
     assert safe_math_package.__repr__() == "<Package safe-math-lib==1.0.0>"
     assert safe_math_package.contract_types == ["SafeMathLib"]
+
+
+def test_cached_properties(piper_coin_manifest, safe_math_lib_package,
+                           safe_math_lib_package_with_alias, w3):
+    package1 = Package(piper_coin_manifest, w3)
+    package2 = Package(piper_coin_manifest, w3)
+    first_build_dependencies_package1 = package1.build_dependencies.items()
+    second_build_dependencies_package1 = package1.build_dependencies.items()
+    assert first_build_dependencies_package1 == second_build_dependencies_package1
+    first_build_dependencies_package2 = package2.build_dependencies.items()
+    second_build_dependencies_package2 = package2.build_dependencies.items()
+    assert first_build_dependencies_package2 == first_build_dependencies_package2
+    assert not first_build_dependencies_package1 == first_build_dependencies_package2
+    assert not second_build_dependencies_package1 == second_build_dependencies_package2
+    package1 = safe_math_lib_package
+    first_deployments_package1 = package1.deployments
+    second_deployments_package1 = package1.deployments
+    assert first_deployments_package1 == second_deployments_package1
+    package2 = safe_math_lib_package_with_alias
+    first_deployments_package2 = package2.deployments
+    second_deployments_package2 = package2.deployments
+    assert first_deployments_package2 == second_deployments_package2
+    assert not first_deployments_package1 == first_deployments_package2
+    assert not second_deployments_package1 == second_deployments_package2