text: # Copyright 2019-2020 Canonical Ltd.
  #
  # 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
  #
  # http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  import os
  import pathlib
  import subprocess
  import shutil
  import tempfile
  import unittest
  
  from ops.framework import Framework
  from ops.model import Model, _ModelBackend
  from ops.charm import CharmMeta
  from ops.storage import SQLiteStorage
  
  
  def fake_script(test_case, name, content):
      if not hasattr(test_case, 'fake_script_path'):
          fake_script_path = tempfile.mkdtemp('-fake_script')
          old_path = os.environ["PATH"]
          os.environ['PATH'] = os.pathsep.join([fake_script_path, os.environ["PATH"]])
  
          def cleanup():
              shutil.rmtree(fake_script_path)
              os.environ['PATH'] = old_path
  
          test_case.addCleanup(cleanup)
          test_case.fake_script_path = pathlib.Path(fake_script_path)
  
      template_args = {
          'name': name,
          'path': test_case.fake_script_path.as_posix(),
          'content': content,
      }
  
      path = test_case.fake_script_path / name
      with path.open('wt') as f:
          # Before executing the provided script, dump the provided arguments in calls.txt.
          # ASCII 1E is RS 'record separator', and 1C is FS 'file separator', which seem appropriate.
          f.write('''#!/bin/sh
  {{ printf {name}; printf "\\036%s" "$@"; printf "\\034"; }} >> {path}/calls.txt
  {content}'''.format_map(template_args))
      os.chmod(str(path), 0o755)
      # TODO: this hardcodes the path to bash.exe, which works for now but might
      #       need to be set via environ or something like that.
      path.with_suffix(".bat").write_text(
          '@"C:\\Program Files\\git\\bin\\bash.exe" {} %*\n'.format(path))
  
  
  def fake_script_calls(test_case, clear=False):
      calls_file = test_case.fake_script_path / 'calls.txt'
      if not calls_file.exists():
          return []
  
      # newline and encoding forced to linuxy defaults because on
      # windows they're written from git-bash
      with calls_file.open('r+t', newline='\n', encoding='utf8') as f:
          calls = [line.split('\x1e') for line in f.read().split('\x1c')[:-1]]
          if clear:
              f.truncate(0)
      return calls
  
  
  class FakeScriptTest(unittest.TestCase):
  
      def test_fake_script_works(self):
          fake_script(self, 'foo', 'echo foo runs')
          fake_script(self, 'bar', 'echo bar runs')
          # subprocess.getoutput goes via the shell, so it needs to be
          # something both sh and CMD understand
          output = subprocess.getoutput('foo a "b c " && bar "d e" f')
          self.assertEqual(output, 'foo runs\nbar runs')
          self.assertEqual(fake_script_calls(self), [
              ['foo', 'a', 'b c '],
              ['bar', 'd e', 'f'],
          ])
  
      def test_fake_script_clear(self):
          fake_script(self, 'foo', 'echo foo runs')
  
          output = subprocess.getoutput('foo a "b c"')
          self.assertEqual(output, 'foo runs')
  
          self.assertEqual(fake_script_calls(self, clear=True), [['foo', 'a', 'b c']])
  
          fake_script(self, 'bar', 'echo bar runs')
  
          output = subprocess.getoutput('bar "d e" f')
          self.assertEqual(output, 'bar runs')
  
          self.assertEqual(fake_script_calls(self, clear=True), [['bar', 'd e', 'f']])
  
          self.assertEqual(fake_script_calls(self, clear=True), [])
  
  
  class BaseTestCase(unittest.TestCase):
  
      def create_framework(self, *, model=None, tmpdir=None):
          """Create a Framework object.
  
          By default operate in-memory; pass a temporary directory via the 'tmpdir'
          parameter if you whish to instantiate several frameworks sharing the
          same dir (e.g. for storing state).
          """
          if tmpdir is None:
              data_fpath = ":memory:"
              charm_dir = 'non-existant'
          else:
              data_fpath = tmpdir / "framework.data"
              charm_dir = tmpdir
  
          framework = Framework(SQLiteStorage(data_fpath), charm_dir, meta=None, model=model)
          self.addCleanup(framework.close)
          return framework
  
      def create_model(self):
          """Create a Model object."""
          backend = _ModelBackend(unit_name='myapp/0')
          meta = CharmMeta()
          model = Model(meta, backend)
          return model
  