You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

163 lines
4.9 KiB

# Script which modifies source code away from the deprecated "flask.ext"
# format.
#
# Run in the terminal by typing: `python flaskext_migrate.py <source_file.py>`
#
# Author: Keyan Pishdadian 2015
from redbaron import RedBaron
import sys
def read_source(input_file):
"""Parses the input_file into a RedBaron FST."""
with open(input_file, "r") as source_code:
red = RedBaron(source_code.read())
return red
def write_source(red, input_file):
"""Overwrites the input_file once the FST has been modified."""
with open(input_file, "w") as source_code:
source_code.write(red.dumps())
def fix_imports(red):
"""Wrapper which fixes "from" style imports and then "import" style."""
red = fix_standard_imports(red)
red = fix_from_imports(red)
return red
def fix_from_imports(red):
"""
Converts "from" style imports to not use "flask.ext".
Handles:
Case 1: from flask.ext.foo import bam --> from flask_foo import bam
Case 2: from flask.ext import foo --> import flask_foo as foo
"""
from_imports = red.find_all("FromImport")
for x, node in enumerate(from_imports):
values = node.value
if len(values) < 2:
continue
if (values[0].value == 'flask') and (values[1].value == 'ext'):
# Case 1
if len(node.value) == 3:
package = values[2].value
modules = node.modules()
module_string = _get_modules(modules)
if len(modules) > 1:
node.replace("from flask_%s import %s"
% (package, module_string))
else:
name = node.names()[0]
node.replace("from flask_%s import %s as %s"
% (package, module_string, name))
# Case 2
else:
module = node.modules()[0]
node.replace("import flask_%s as %s"
% (module, module))
return red
def fix_standard_imports(red):
"""
Handles import modification in the form:
import flask.ext.foo" --> import flask_foo
"""
imports = red.find_all("ImportNode")
for x, node in enumerate(imports):
try:
if (node.value[0].value[0].value == 'flask' and
node.value[0].value[1].value == 'ext'):
package = node.value[0].value[2].value
name = node.names()[0].split('.')[-1]
if name == package:
node.replace("import flask_%s" % (package))
else:
node.replace("import flask_%s as %s" % (package, name))
except IndexError:
pass
return red
def _get_modules(module):
"""
Takes a list of modules and converts into a string.
The module list can include parens, this function checks each element in
the list, if there is a paren then it does not add a comma before the next
element. Otherwise a comma and space is added. This is to preserve module
imports which are multi-line and/or occur within parens. While also not
affecting imports which are not enclosed.
"""
modules_string = [cur + ', ' if cur.isalnum() and next.isalnum()
else cur
for (cur, next) in zip(module, module[1:]+[''])]
return ''.join(modules_string)
def fix_function_calls(red):
"""
Modifies function calls in the source to reflect import changes.
Searches the AST for AtomtrailerNodes and replaces them.
"""
atoms = red.find_all("Atomtrailers")
for x, node in enumerate(atoms):
try:
if (node.value[0].value == 'flask' and
node.value[1].value == 'ext'):
params = _form_function_call(node)
node.replace("flask_%s%s" % (node.value[2], params))
except IndexError:
pass
return red
def _form_function_call(node):
"""
Reconstructs function call strings when making attribute access calls.
"""
node_vals = node.value
output = "."
for x, param in enumerate(node_vals[3::]):
if param.dumps()[0] == "(":
output = output[0:-1] + param.dumps()
return output
else:
output += param.dumps() + "."
def check_user_input():
"""Exits and gives error message if no argument is passed in the shell."""
if len(sys.argv) < 2:
sys.exit("No filename was included, please try again.")
def fix_tester(ast):
"""Wrapper which allows for testing when not running from shell."""
ast = fix_imports(ast)
ast = fix_function_calls(ast)
return ast.dumps()
def fix():
"""Wrapper for user argument checking and import fixing."""
check_user_input()
input_file = sys.argv[1]
ast = read_source(input_file)
ast = fix_imports(ast)
ast = fix_function_calls(ast)
write_source(ast, input_file)
if __name__ == "__main__":
fix()