Develop

src/briefcase/commands/new.py

@@ -7,7 +7,7 @@
 
 from cookiecutter import exceptions as cookiecutter_exceptions
 
-from briefcase.config import PEP508_NAME_RE
+
 from briefcase.exceptions import NetworkFailure
 
 from .base import BaseCommand, BriefcaseCommandError
@@ -74,26 +74,14 @@ def add_options(self, parser):
             help='The cookiecutter template to use for the new project'
         )
 
-    def make_class_name(self, formal_name):
-        """
-        Construct a valid class name from a formal name.
-
-        :param formal_name: The formal name
-        :returns: The app's class name
-        """
-        class_name = re.sub('[^0-9a-zA-Z_]+', '', formal_name)
-        if class_name[0].isdigit():
-            class_name = '_' + class_name
-        return class_name
-
     def make_app_name(self, formal_name):
         """
         Construct a candidate app name from a formal name.
 
         :param formal_name: The formal name
         :returns: The candidate app name
         """
-        return re.sub('[^0-9a-zA-Z_]+', '', formal_name).lstrip('_').lower()
+        return re.sub('[^a-zA-Z]*[^a-zA-Z0-9_]+', '', formal_name).lstrip('_').rstrip('_').lower()
 
     def validate_app_name(self, candidate):
         """
@@ -103,10 +91,11 @@ def validate_app_name(self, candidate):
         :returns: True. If there are any validation problems, raises ValueError
             with a diagnostic message.
         """
-        if not PEP508_NAME_RE.match(candidate):
+        if not re.match('^[a-z][a-zA-Z0-9._-]*[a-zA-Z0-9]$', candidate):
             raise ValueError(
-                "App name may only contain letters, numbers, hypens and "
-                "underscores, and may not start with a hyphen or underscore."
+                "App names must be PEP508 compliant (i.e., they can only "
+                "include letters, numbers, '-' and '_'; must start with a "
+                "letter; and cannot end with '-' or '_'."
             )
         if (self.base_path / candidate).exists():
             raise ValueError(
@@ -117,6 +106,33 @@ def validate_app_name(self, candidate):
 
         return True
 
+    def make_class_name(self, formal_name):
+        """
+        Construct a candidate class name from a formal name.
+
+        :param formal_name: The formal name
+        :returns: The candidate app name; will appear blank if only non-latin characters
+        were entered in the formal_name
+        """
+        formal_name.title()
+        return re.sub('[^a-zA-Z]*[^a-zA-Z0-9_]+', '', formal_name)
+
+    def validate_class_name(self, candidate):
+        """
+        Determine if class name is valid
+
+        :param candidate: The candidate name
+        :returns: True. If there are any validation problems, raises ValueError
+            with a diagnostic message.
+        """
+        if not re.match('^[A-Z]+[a-zA-Z0-9_]+$', candidate):
+            raise ValueError(
+                "The class name must start with a capital letter in the CapWords format."
+                "It should not contain spaces."
+            )
+
+        return True
+
     def make_module_name(self, app_name):
         """
         Construct a valid module name from an app name.
@@ -317,9 +333,6 @@ def build_app_context(self):
             default='Hello World',
         )
 
-        # The class name can be completely derived from the formal name.
-        class_name = self.make_class_name(formal_name)
-
         default_app_name = self.make_app_name(formal_name)
         app_name = self.input_text(
             intro="""
@@ -337,6 +350,16 @@ def build_app_context(self):
             validator=self.validate_app_name,
         )
 
+        default_class_name = self.make_class_name(formal_name)
+        class_name = self.input_text(
+            intro="""
+Next, we need a name that will serve as the App class name. The class name must start with 
+a capital letter in the CapWords format. It should not contain spaces.""",
+            variable="class name",
+            default=default_class_name,
+            validator=self.validate_class_name,
+        )
+
         # The module name can be completely derived from the app name.
         module_name = self.make_module_name(app_name)
 

tests/commands/new/test_build_app_context.py

@@ -6,6 +6,7 @@ def test_question_sequence(new_command):
     new_command.input.values = [
         'My Application',  # formal name
         '',  # app name - accept the default
+        '',  # class name
         'org.beeware',  # bundle ID
         'My Project',  # project name
         'Cool stuff',  # description
@@ -18,8 +19,8 @@ def test_question_sequence(new_command):
 
     assert new_command.build_app_context() == {
         'formal_name': 'My Application',
-        'class_name': 'MyApplication',
         'app_name': 'myapplication',
+        'class_name': 'MyApplication',
         'module_name': 'myapplication',
         'bundle': 'org.beeware',
         'project_name': 'My Project',
@@ -39,6 +40,7 @@ def test_question_sequence_with_nondefault_gui(new_command):
     new_command.input.values = [
         'My Application',  # formal name
         '',  # app name - accept the default
+        '',  # class name
         'org.beeware',  # bundle ID
         'My Project',  # project name
         'Cool stuff',  # description
@@ -51,8 +53,8 @@ def test_question_sequence_with_nondefault_gui(new_command):
 
     assert new_command.build_app_context() == {
         'formal_name': 'My Application',
-        'class_name': 'MyApplication',
         'app_name': 'myapplication',
+        'class_name': 'MyApplication',
         'module_name': 'myapplication',
         'bundle': 'org.beeware',
         'project_name': 'My Project',

tests/commands/new/test_make_app_name.py

@@ -8,6 +8,12 @@
         ('Hello World!', 'helloworld'),
         ('Hello! World', 'helloworld'),
         ('Hello-World', 'helloworld'),
+        ('98 Hello World', 'helloworld'),
+        ('Hello World_', 'helloworld'),
+        ('Hello world.', 'helloworld'),
+        ('_HelloWorld_', 'helloworld'),
+        ('Hello_World_', 'hello_world'),
+        ('Hello World-', 'helloworld'),
     ]
 )
 def test_make_app_name(new_command, formal_name, candidate):

tests/commands/new/test_make_class_name.py

@@ -9,7 +9,7 @@
         ('Hello! World', 'HelloWorld'),
         ('Hello_World', 'Hello_World'),
         ('Hello-World', 'HelloWorld'),
-        ('24 Jump Street', '_24JumpStreet'),
+        ('24 Jump Street', 'JumpStreet'),
     ]
 )
 def test_make_class_name(new_command, formal_name, candidate):

tests/commands/new/test_validate_app_name.py

@@ -7,7 +7,6 @@
         'helloworld',
         'helloWorld',
         'hello42world',
-        '42helloworld',  # ?? Are we sure this is correct?
         'hello_world',
         'hello-world',
     ]
@@ -25,6 +24,10 @@ def test_valid_app_name(new_command, name):
         '_helloworld',  # leading underscore
         '-helloworld',  # leading hyphen
         'existing',  # pre-existing directory
+        '98helloworld',  # leading digit
+        '',  # blank
+        '学口算',  # non-latin character
+        'Helloworld'  # start with capital letter
     ]
 )
 def test_invalid_app_name(new_command, name, tmp_path):

tests/commands/new/test_validate_class_name.py

@@ -0,0 +1,36 @@
+import pytest
+
+
+@pytest.mark.parametrize(
+    'name',
+    [
+        'HelloWorld',
+        'HelloWorld98',
+        'Hello42World',
+        'Hello_World',
+    ]
+)
+def test_valid_class_name(new_command, name):
+    "Test that valid app names are accepted"
+    assert new_command.validate_class_name(name)
+
+
+@pytest.mark.parametrize(
+    'name',
+    [
+        'hello world',  # space
+        'helloworld!',  # punctuation
+        '_helloworld',  # leading underscore
+        '-helloworld',  # leading hyphen
+        '98helloworld',  # leading digit
+        '',  # blank
+        '学口算',  # non-latin character
+        'helloworld',  # no capitalized letter
+    ]
+)
+def test_invalid_class_name(new_command, name, tmp_path):
+    "Test that invalid app names are rejected"
+    (tmp_path / 'existing').mkdir()
+
+    with pytest.raises(ValueError):
+        new_command.validate_class_name(name)