Source code for luigi.mock

# -*- coding: utf-8 -*-
# Copyright 2012-2015 Spotify AB
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# See the License for the specific language governing permissions and
# limitations under the License.
This module provides a class :class:`MockTarget`, an implementation of :py:class:``.
:class:`MockTarget` contains all data in-memory.
The main purpose is unit testing workflows without writing to disk.

import multiprocessing
from io import BytesIO

import sys

from luigi import six
from luigi import target
from luigi.format import get_default_format, MixedUnicodeBytes

[docs]class MockFileSystem(target.FileSystem): """ MockFileSystem inspects/modifies _data to simulate file system operations. """ _data = None
[docs] def copy(self, path, dest, raise_if_exists=False): """ Copies the contents of a single file path to dest """ if raise_if_exists and dest in self.get_all_data(): raise RuntimeError('Destination exists: %s' % path) contents = self.get_all_data()[path] self.get_all_data()[dest] = contents
[docs] def get_all_data(self): # This starts a server in the background, so we don't want to do it in the global scope if MockFileSystem._data is None: MockFileSystem._data = multiprocessing.Manager().dict() return MockFileSystem._data
[docs] def get_data(self, fn): return self.get_all_data()[fn]
[docs] def exists(self, path): return MockTarget(path).exists()
[docs] def remove(self, path, recursive=True, skip_trash=True): """ Removes the given mockfile. skip_trash doesn't have any meaning. """ if recursive: to_delete = [] for s in self.get_all_data().keys(): if s.startswith(path): to_delete.append(s) for s in to_delete: self.get_all_data().pop(s) else: self.get_all_data().pop(path)
[docs] def move(self, path, dest, raise_if_exists=False): """ Moves a single file from path to dest """ if raise_if_exists and dest in self.get_all_data(): raise RuntimeError('Destination exists: %s' % path) contents = self.get_all_data().pop(path) self.get_all_data()[dest] = contents
[docs] def listdir(self, path): """ listdir does a prefix match of self.get_all_data(), but doesn't yet support globs. """ return [s for s in self.get_all_data().keys() if s.startswith(path)]
[docs] def isdir(self, path): return any(self.listdir(path))
[docs] def mkdir(self, path, parents=True, raise_if_exists=False): """ mkdir is a noop. """ pass
[docs] def clear(self): self.get_all_data().clear()
[docs]class MockTarget(target.FileSystemTarget): fs = MockFileSystem() def __init__(self, fn, is_tmp=None, mirror_on_stderr=False, format=None): self._mirror_on_stderr = mirror_on_stderr self.path = fn if format is None: format = get_default_format() # Allow to write unicode in file for retrocompatibility if six.PY2: format = format >> MixedUnicodeBytes self.format = format
[docs] def exists(self,): return self.path in self.fs.get_all_data()
[docs] def move(self, path, raise_if_exists=False): """ Call MockFileSystem's move command """ self.fs.move(self.path, path, raise_if_exists)
[docs] def rename(self, *args, **kwargs): """ Call move to rename self """ self.move(*args, **kwargs)
[docs] def open(self, mode='r'): fn = self.path mock_target = self class Buffer(BytesIO): # Just to be able to do writing + reading from the same buffer _write_line = True def set_wrapper(self, wrapper): self.wrapper = wrapper def write(self, data): if mock_target._mirror_on_stderr: if self._write_line: sys.stderr.write(fn + ": ") if six.binary_type: sys.stderr.write(data.decode('utf8')) else: sys.stderr.write(data) if (data[-1]) == '\n': self._write_line = True else: self._write_line = False super(Buffer, self).write(data) def close(self): if mode[0] == 'w': try: mock_target.wrapper.flush() except AttributeError: pass mock_target.fs.get_all_data()[fn] = self.getvalue() super(Buffer, self).close() def __exit__(self, exc_type, exc_val, exc_tb): if not exc_type: self.close() def __enter__(self): return self def readable(self): return mode[0] == 'r' def writeable(self): return mode[0] == 'w' def seekable(self): return False if mode[0] == 'w': wrapper = self.format.pipe_writer(Buffer()) wrapper.set_wrapper(wrapper) return wrapper else: return self.format.pipe_reader(Buffer(self.fs.get_all_data()[fn]))