added unused dependencies finder

edx_repo_tools/unused_dependencies/__init__.py

@@ -0,0 +1,9 @@
+from sys import argv
+
+from unused_dependencies import unused_dependencies
+
+if __name__ == '__main__':
+    if len(argv) < 2:
+        print("Usage: python unused_dependencies.py <repo-name>")
+        exit(-1)
+    print(unused_dependencies(argv[1]))

edx_repo_tools/unused_dependencies/config.py

@@ -0,0 +1,3 @@
+blacklist = {'.', '..', '.ci', 'node_modules', 'static', 'public', 'build', 'docs', 'media', 'scripts','.github', '.git', 'requirements', 'tests', '.tox', 'migrations', 'test_utils', 'tests', '__pycache__'}
+
+whitelist = {'tox', 'pip', 'twine', 'pydocstyle', 'wheel', 'edx-sphinx-theme', 'edx-lint', 'pytest-cookies', 'pycodestyle', 'build', 'Sphinx', 'doc8', 'virtualenv', 'pip-tools', 'tox-battery', 'sphinx_rtd_theme'}

edx_repo_tools/unused_dependencies/gather_imports.py

@@ -0,0 +1,80 @@
+
+import ast
+import re
+
+from os import listdir
+from os.path import join
+from genericpath import isdir, isfile
+
+from config import blacklist
+
+# can't use ast because .py files include invalid identifier e.g. {{cookiecutter.class_name}}
+def parse_imports(path):
+    """
+    parses `path` as a python file and returns the list of all the modules
+    imported in the file. Any sub-modules imported will be ignored and the
+    base module will be considered.
+    """
+    with open(path) as fh:  
+        root = ast.parse(fh.read(), path)
+
+    for node in ast.iter_child_nodes(root):
+        if isinstance(node, ast.Import):
+            # import package.module -> package
+            module = node.names[0].name.split('.')[0]
+        elif isinstance(node, ast.ImportFrom):
+            if node.module is None:
+                continue
+            # from package.module import name, othername -> package
+            module = node.module.split('.')[0]
+        else:
+            continue
+        yield module
+
+
+def manually_parse_imports(path):
+    """
+    parses `path` as a python file and returns the list of all the modules
+    imported in the file. Any sub-modules imported will be ignored and the
+    base module will be considered.
+    """
+    import_match  = re.compile("^(from|import)")
+    from_import = re.compile('^from (.*) import')
+    package_import = re.compile('^import (.*)')
+
+    with open(path) as f:
+        isdocstring = False
+        for line in f:
+            line = line.strip()
+            if not line:
+                continue
+            if line.startswith('"""'):
+                isdocstring = not isdocstring
+                continue
+            if isdocstring:
+                continue
+            if line.startswith('#'):
+                continue
+            if import_match.match(line) is None:
+                # we don't support imports anywhere other then the top of file
+                break
+
+            package = from_import.match(line) if line.startswith('from') else package_import.match(line)
+            yield package.groups()[0].split(' ')[0].split('.')[0]
+
+def gather_imports( path, imports = set()):
+    """
+    Walks `path` recursively and parses each .py file to generate a set of
+    all the imports.
+    """
+    content = listdir(path)
+    files = [f for f in content if isfile(join(path, f))]
+    for file in files:
+        if file.endswith('.py'):
+            imports.update(manually_parse_imports(join(path, file)))
+
+    dirs = {d for d in content if isdir(join(path, d))}
+    for dir in dirs - blacklist:
+        gather_imports(join(path, dir))
+
+    return imports

edx_repo_tools/unused_dependencies/populate_requirements.py

@@ -0,0 +1,22 @@
+
+from os import walk
+from os.path import join
+
+
+def populate_requirements(path, requirements = set()):
+    """
+    returns a set of all the requirements listed in any .in file inside
+    `path`. The version numbers and comments are removed from the returned
+    set.
+    """
+    for dirpath, dirs, files in walk(path):
+        for file in files:
+            if file.endswith('.in'):
+                filepath = join(dirpath, file)
+                with open(filepath) as req_file:
+                    # `package=10.3 # some comments` -> package
+                    requirements.update(package.split(' ')[0].split('=')[0].strip('\n') for package in req_file if package[0] not in ['#', '-', '\n', ' '])
+        for dir in dirs:
+            populate_requirements(join(dirpath, dir), requirements)
+
+    return requirements

edx_repo_tools/unused_dependencies/unused_dependencies.py

@@ -0,0 +1,22 @@
+from os.path import join, exists
+
+from populate_requirements import populate_requirements
+from gather_imports import gather_imports
+from config import whitelist
+
+
+def unused_dependencies(path):
+    """
+    check for any package listed in any .in file that is not imported in
+    any .py file.
+    """
+    if not exists(path):
+        print("Error: {} doesn't exist.".format(path))
+        exit(1)
+    requirements = populate_requirements(join(path, 'requirements'))
+    imports = gather_imports(path)
+
+    print(requirements)
+    print(imports)
+    unused = (requirements - imports) - whitelist
+    assert len(unused) == 0, "The following packages are unused: {}".format(unused)