Add a multi-language CRAP tool that writes .metrics/crap.edn for uml-viewer.

Score Clojure, Java, Go, TypeScript, Rust, and Python with each language's complexity rules and coverage report.

tests/test_python.py

@@ -0,0 +1,105 @@
+from crapper.languages.python import functions_in_source
+
+
+def test_function_method_and_nested_function():
+    source = """
+def choose(x, ready):
+    if x > 0 and x < 10:
+        return 1
+    elif x == 0 or ready:
+        return 0
+    for i in xs:
+        if i == 2:
+            return i
+    while ready:
+        break
+    try:
+        return x
+    except ValueError:
+        return 0
+    except KeyError:
+        return -1
+    match x:
+        case 1:
+            return 1
+        case 2 | 3:
+            return 2
+        case _:
+            return 0
+    return x if x > 0 else 0
+
+class Box:
+    def open(self, flag=False):
+        return 1 if flag else 0
+
+    @staticmethod
+    def shut(self):
+        xs = [n for n in range(3) if n]
+        return xs
+
+def outer():
+    def inner(n):
+        if n:
+            return 1
+        return 0
+    return inner(1)
+
+async def load():
+    if True:
+        return 1
+"""
+    functions = functions_in_source(source, "src/demo/box.py", "/proj")
+    assert [(fn.namespace, fn.name, fn.complexity) for fn in functions] == [
+        ("demo.box", "choose", 14),
+        ("demo.box.Box", "open", 2),
+        ("demo.box.Box", "shut", 2),
+        ("demo.box", "outer", 2),
+        ("demo.box", "load", 2),
+    ]
+
+
+def test_nested_class_method_is_its_own_entry():
+    source = """
+class Outer:
+    class Inner:
+        def tick(self, ready, ok):
+            if ready and ok:
+                return 1
+            return 0
+
+def factory():
+    class Hidden:
+        def secret(self):
+            if True:
+                return 1
+            return 0
+    return Hidden()
+"""
+    functions = functions_in_source(source, "src/demo/sample.py", "/proj")
+    assert [(fn.namespace, fn.name, fn.complexity) for fn in functions] == [
+        ("demo.sample.Outer.Inner", "tick", 3),
+        ("demo.sample", "factory", 1),
+        ("demo.sample.Hidden", "secret", 2),
+    ]
+
+
+def test_namespace_strips_roots_src_and_init():
+    source = "def f():\n    return 1\n"
+    assert functions_in_source(source, "/proj/src/demo/app.py", "/proj")[0].namespace == "demo.app"
+    assert functions_in_source(source, "./src/demo/app.py", ".")[0].namespace == "demo.app"
+    assert functions_in_source(source, "pkg/src/demo/__init__.py", None)[0].namespace == "demo"
+    assert functions_in_source(source, "__init__.py", None)[0].namespace == "__init__"
+
+
+def test_strings_comments_and_package_init_do_not_add_decisions():
+    source = '''
+def literal():
+    """if and or for while except"""
+    text = "if x and y"
+    # if x: return 1
+    return text
+'''
+    functions = functions_in_source(source, "src/demo/__init__.py", "/proj")
+    assert [(fn.namespace, fn.name, fn.complexity) for fn in functions] == [
+        ("demo", "literal", 1)
+    ]