Rename TemplateProject -> TestProject & tidy some comments

test/test_projects/__init__.py

@@ -0,0 +1,2 @@
+from .base import TestProject  # noqa
+from .c import new_c_project  # noqa

test/test_projects/__main__.py

@@ -0,0 +1,37 @@
+from argparse import ArgumentParser
+import importlib
+import tempfile
+import sys
+import subprocess
+
+
+def main():
+    parser = ArgumentParser(
+        prog="python -m test.test_projects",
+        description='Generate a test project to check it out'
+    )
+    parser.add_argument('PROJECT', help='''
+        Python path to a project object. E.g. test.test_0_basic.basic_project
+    ''')
+    options = parser.parse_args()
+
+    module, _, name = options.PROJECT.rpartition('.')
+
+    project = getattr(importlib.import_module(module), name)
+
+    project_dir = tempfile.mkdtemp()
+    project.generate(project_dir)
+
+    print('Project generated at', project_dir)
+    print()
+
+    if sys.platform == 'darwin':
+        subprocess.check_call(['open', '--', project_dir])
+    elif sys.platform == 'linux2':
+        subprocess.check_call(['xdg-open', '--', project_dir])
+    elif sys.platform == 'win32':
+        subprocess.check_call(['explorer', project_dir])
+
+
+if __name__ == '__main__':
+    main()

test/test_projects/base.py

@@ -0,0 +1,39 @@
+import os
+import jinja2
+from typing import Union, Dict, Any
+
+
+FilesDict = Dict[str, Union[str, jinja2.Template]]
+TemplateContext = Dict[str, Any]
+
+
+class TestProject:
+    '''
+    An object that represents a project that can be built by cibuildwheel.
+    Can be manipulated in tests by changing `files` and `template_context`.
+
+    Write out to the filesystem using `generate`.
+    '''
+    files: FilesDict
+    template_context: TemplateContext
+
+    def __init__(self):
+        self.files = {}
+        self.template_context = {}
+
+    def generate(self, path: str):
+        for filename, content in self.files.items():
+            file_path = os.path.join(path, filename)
+            os.makedirs(os.path.dirname(file_path), exist_ok=True)
+
+            with open(file_path, 'w', encoding='utf8') as f:
+                if isinstance(content, jinja2.Template):
+                    content = content.render(self.template_context)
+
+                f.write(content)
+
+    def copy(self):
+        other = TestProject()
+        other.files = self.files.copy()
+        other.template_context = self.template_context.copy()
+        return other

test/test_projects/c.py

@@ -0,0 +1,100 @@
+import jinja2
+from .base import TestProject
+
+
+SPAM_C_TEMPLATE = r'''
+#include <Python.h>
+
+{{ spam_c_top_level_add }}
+
+static PyObject *
+spam_system(PyObject *self, PyObject *args)
+{
+    const char *command;
+    int sts;
+
+    if (!PyArg_ParseTuple(args, "s", &command))
+        return NULL;
+
+    sts = system(command);
+
+    {{ spam_c_function_add | indent(4) }}
+
+    return PyLong_FromLong(sts);
+}
+
+/* Module initialization */
+
+#if PY_MAJOR_VERSION >= 3
+    #define MOD_INIT(name) PyMODINIT_FUNC PyInit_##name(void)
+    #define MOD_DEF(m, name, doc, methods, module_state_size) \
+        static struct PyModuleDef moduledef = { \
+            PyModuleDef_HEAD_INIT, name, doc, module_state_size, methods, }; \
+        m = PyModule_Create(&moduledef);
+    #define MOD_RETURN(m) return m;
+#else
+    #define MOD_INIT(name) PyMODINIT_FUNC init##name(void)
+    #define MOD_DEF(m, name, doc, methods, module_state_size) \
+        m = Py_InitModule3(name, methods, doc);
+    #define MOD_RETURN(m) return;
+#endif
+
+static PyMethodDef module_methods[] = {
+    {"system", (PyCFunction)spam_system, METH_VARARGS,
+     "Execute a shell command."},
+    {NULL}  /* Sentinel */
+};
+
+MOD_INIT(spam)
+{
+    PyObject* m;
+
+    MOD_DEF(m,
+            "spam",
+            "Example module",
+            module_methods,
+            -1)
+
+    MOD_RETURN(m)
+}
+'''
+
+SETUP_PY_TEMPLATE = r'''
+from setuptools import setup, Extension
+
+{{ setup_py_add }}
+
+setup(
+    ext_modules=[Extension('spam', sources=['spam.c'])],
+    {{ setup_py_setup_args_add | indent(4) }}
+)
+'''
+
+SETUP_CFG_TEMPLATE = r'''
+[metadata]
+name = spam
+version = 0.1.0
+
+{{ setup_cfg_add }}
+'''
+
+
+def new_c_project(*, spam_c_top_level_add='', spam_c_function_add='', setup_py_add='',
+                  setup_py_setup_args_add='', setup_cfg_add=''):
+    project = TestProject()
+
+    project.files.update({
+        'spam.c': jinja2.Template(SPAM_C_TEMPLATE),
+        'setup.py': jinja2.Template(SETUP_PY_TEMPLATE),
+        'setup.cfg': jinja2.Template(SETUP_CFG_TEMPLATE),
+    })
+
+    project.template_context.update({
+        'spam_c_top_level_add': spam_c_top_level_add,
+        'spam_c_function_add': spam_c_function_add,
+        'setup_py_add': setup_py_add,
+        'setup_py_setup_args_add': setup_py_setup_args_add,
+        'setup_cfg_add': setup_cfg_add,
+    })
+
+    return project