Migrate existing challenges, update contribution guidance

Author: laike9m

challenges/advanced-generic-param/question.py

@@ -18,7 +18,5 @@ def unwrap(self):
 ## End of your code ##
 from typing import assert_type
 
-
-def should_pass(w: Box[str]):
-    assert_type(w.unwrap(), str)
-    assert_type(Box(1).unwrap(), int)
+assert_type(w.unwrap(), str)
+assert_type(Box(1).unwrap(), int)

challenges/advanced-overload/question.py

@@ -12,12 +12,8 @@ def foo(value=None):
 ## End of your code ##
 from typing import assert_type
 
+assert_type(foo(42), str)
+assert_type(foo(), int)
 
-def should_pass():
-    assert_type(foo(42), str)
-    assert_type(foo(), int)
-
-
-def should_fail():
-    assert_type(foo(42), int)  # expect-type-error
-    assert_type(foo(), str)  # expect-type-error
+assert_type(foo(42), int)  # expect-type-error
+assert_type(foo(), str)  # expect-type-error

challenges/advanced-self/question.py

@@ -17,10 +17,7 @@ class SubclassOfFoo(Foo):
     pass
 
 
-def should_pass():
-    f: Foo = Foo().return_self()
-    sf: SubclassOfFoo = SubclassOfFoo().return_self()
+f: Foo = Foo().return_self()
+sf: SubclassOfFoo = SubclassOfFoo().return_self()
 
-
-def should_fail():
-    sf: SubclassOfFoo = Foo().return_self()  # expect-type-error
+sf: SubclassOfFoo = Foo().return_self()  # expect-type-error

docs/Contribute.md

@@ -8,68 +8,27 @@
 
    For example, say you want to add a new challenge about [Protocols](https://mypy.readthedocs.io/en/stable/protocols.html). Since this is an advanced topic, you may name the directory `advanced-protocol`.
 
-4. Put a `question.py` and a `solution.py` in the new directory. Here's an example:
+4. Put a `question.py` and a `solution.py` in the new directory. Here's an example `question.py`:
    ```python
    """
    TODO:
-
-   foo should accept a dict argument, both keys and values are string.
+     foo should accept a dict argument, both keys and values are string.
    """
 
    def foo(x):
        pass
 
-   def should_pass():
-       foo({"foo": "bar"})
-
-   def should_fail():
-       foo({"foo": 1})
-   ```
-
-   You want to include several things in `question.py`
-
-   - Describe the challenge, make sure people understand what they need to accomplish (the `TODO:` part)
-   - Add two functions `should_pass` and `should_fail` as test cases. The **function names are mandatory**. With correct code, `should_pass` should pass type check, and `should_fail` should fail type check.
-
-   Using the above challenge as an example, the correct answer is `def foo(x: dict[str, str]): pass`.
-
-   This will pass type check:
-
-   ```python
-   def foo(x: dict[str, str]):
-       pass
-
-   def should_pass():
-       foo({"foo": "bar"})
-   ```
-
-   This will fail type check
-
-   ```python
-   def foo(x: dict[str, str]):
-       pass
-
-   def should_fail():
-       foo({"foo": 1})
+   ## End of your code ##
+   foo({"foo": "bar"})
+   foo({"foo": 1})  # expect-type-error
    ```
 
-   And the `solution.py` shall look like the same as `question.py`, except that it has a solution provided.
+   You want to include several things in `question.py`:
+   - Describe the challenge, make sure people understand what they need to accomplish (i.e. the `TODO:` part)
+   - A comment `## End of your code ##`. This is mandatory, just copy and paste it.
+   - Several test cases. Add a comment `# expect-type-error` after the lines where type errors should be thrown.
 
-   ```python
-   """
-   TODO:
-
-   foo should accept a dict argument, both keys and values are string.
-   """
-
-   def foo(x: dict[str, str]): pass
-
-   def should_pass():
-       foo({"foo": "bar"})
-
-   def should_fail():
-       foo({"foo": 1})
-   ```
+   `solution.py` contains the right solution, with everything else unchanged.
 
 5. Test with [`mypy`](https://mypy.readthedocs.io/) to make sure your new challenge works as expected.