Implement our own subshell logic

To replace Pew's "workon" command. New code built on Shellingham.

This also fixes a few additional minor bugs, e.g. Cmder not launching
Powershell when it should.

pipenv/_compat.py

@@ -34,6 +34,11 @@ def _infer_return_type(*args):
 except ImportError:
     from pathlib2 import Path
 
+# Backport required for earlier versions of Python.
+if sys.version_info < (3, 3):
+    from .vendor.backports.shutil_get_terminal_size import get_terminal_size
+else:
+    from shutil import get_terminal_size
 
 try:
     from weakref import finalize

pipenv/core.py

@@ -81,11 +81,6 @@
     PIPENV_CACHE_DIR,
 )
 
-# Backport required for earlier versions of Python.
-if sys.version_info < (3, 3):
-    from .vendor.backports.shutil_get_terminal_size import get_terminal_size
-else:
-    from shutil import get_terminal_size
 # Packages that should be ignored later.
 BAD_PACKAGES = ('setuptools', 'pip', 'wheel', 'packaging', 'distribute')
 # Are we using the default Python?
@@ -720,7 +715,7 @@ def do_install_dependencies(
     verbose=False,
     concurrent=True,
     requirements_dir=None,
-    pypi_mirror = False,
+    pypi_mirror=False,
 ):
     """"Executes the install functionality.
 
@@ -1006,7 +1001,7 @@ def do_lock(
     pre=False,
     keep_outdated=False,
     write=True,
-    pypi_mirror = None,
+    pypi_mirror=None,
 ):
     """Executes the freeze functionality."""
     from .utils import get_vcs_deps
@@ -1169,29 +1164,6 @@ def do_lock(
         return lockfile
 
 
-def activate_virtualenv(source=True):
-    """Returns the string to activate a virtualenv."""
-    # Suffix and source command for other shells.
-    suffix = ''
-    command = ' .' if source else ''
-    # Support for fish shell.
-    if PIPENV_SHELL and 'fish' in PIPENV_SHELL:
-        suffix = '.fish'
-        command = 'source'
-    # Support for csh shell.
-    if PIPENV_SHELL and 'csh' in PIPENV_SHELL:
-        suffix = '.csh'
-        command = 'source'
-    # Escape any spaces located within the virtualenv path to allow
-    # for proper activation.
-    venv_location = project.virtualenv_location.replace(' ', r'\ ')
-    if source:
-        return '{2} {0}/bin/activate{1}'.format(venv_location, suffix, command)
-
-    else:
-        return '{0}/bin/activate'.format(venv_location)
-
-
 def do_purge(bare=False, downloads=False, allow_global=False, verbose=False):
     """Executes the purge functionality."""
     if downloads:
@@ -1381,7 +1353,7 @@ def pip_install(
     selective_upgrade=False,
     requirements_dir=None,
     extra_indexes=None,
-    pypi_mirror = None,
+    pypi_mirror=None,
 ):
     from notpip._internal import logger as piplogger
     from notpip._vendor.pyparsing import ParseException
@@ -2150,93 +2122,37 @@ def do_uninstall(
 
 
 def do_shell(three=None, python=False, fancy=False, shell_args=None):
-    from .patched.pew import pew
-
     # Ensure that virtualenv is available.
     ensure_project(three=three, python=python, validate=False)
     # Set an environment variable, so we know we're in the environment.
     os.environ['PIPENV_ACTIVE'] = '1'
-    compat = (not fancy)
     # Support shell compatibility mode.
     if PIPENV_SHELL_FANCY:
-        compat = False
-    # Compatibility mode:
-    if compat:
-        if PIPENV_SHELL:
-            shell = os.path.abspath(PIPENV_SHELL)
-        else:
-            click.echo(
-                crayons.red(
-                    'Please ensure that the {0} environment variable '
-                    'is set before activating shell.'.format(
-                        crayons.normal('SHELL', bold=True)
-                    )
-                ),
-                err=True,
-            )
-            sys.exit(1)
+        fancy = True
+
+    from .shells import choose_shell
+    shell = choose_shell()
+    click.echo("Launching subshell in virtual environment…", err=True)
+
+    fork_args = (
+        project.virtualenv_location,
+        project.project_directory,
+        shell_args,
+    )
+
+    if fancy:
+        shell.fork(**fork_args)
+        return
+
+    try:
+        shell.fork_compat(**fork_args)
+    except (AttributeError, ImportError):
         click.echo(
-            crayons.normal(
-                'Spawning environment shell ({0}). Use {1} to leave.'.format(
-                    crayons.red(shell), crayons.normal("'exit'", bold=True)
-                ),
-                bold=True,
-            ),
+            u'Compatibility mode not supported. '
+            u'Trying to continue as well-configured shell…',
             err=True,
         )
-        cmd = "{0} -i'".format(shell)
-        args = []
-    # Standard (properly configured shell) mode:
-    else:
-        if project.is_venv_in_project():
-            # use .venv as the target virtualenv name
-            workon_name = '.venv'
-        else:
-            workon_name = project.virtualenv_name
-        cmd = sys.executable
-        args = ['-m', 'pipenv.pew', 'workon', workon_name]
-    # Grab current terminal dimensions to replace the hardcoded default
-    # dimensions of pexpect
-    terminal_dimensions = get_terminal_size()
-    try:
-        with temp_environ():
-            if project.is_venv_in_project():
-                os.environ['WORKON_HOME'] = project.project_directory
-            c = pexpect.spawn(
-                cmd,
-                args,
-                dimensions=(
-                    terminal_dimensions.lines, terminal_dimensions.columns
-                ),
-            )
-    # Windows!
-    except AttributeError:
-        # import subprocess
-        # Tell pew to use the project directory as its workon_home
-        with temp_environ():
-            if project.is_venv_in_project():
-                os.environ['WORKON_HOME'] = project.project_directory
-            pew.workon_cmd([workon_name])
-            sys.exit(0)
-    # Activate the virtualenv if in compatibility mode.
-    if compat:
-        c.sendline(activate_virtualenv())
-    # Send additional arguments to the subshell.
-    if shell_args:
-        c.sendline(' '.join(shell_args))
-
-    # Handler for terminal resizing events
-    # Must be defined here to have the shell process in its context, since we
-    # can't pass it as an argument
-    def sigwinch_passthrough(sig, data):
-        terminal_dimensions = get_terminal_size()
-        c.setwinsize(terminal_dimensions.lines, terminal_dimensions.columns)
-
-    signal.signal(signal.SIGWINCH, sigwinch_passthrough)
-    # Interact with the new shell.
-    c.interact(escape_character=None)
-    c.close()
-    sys.exit(c.exitstatus)
+        shell.fork(**fork_args)
 
 
 def inline_activate_virtualenv():

pipenv/environments.py

@@ -76,6 +76,7 @@
 SESSION_IS_INTERACTIVE = bool(os.isatty(sys.stdout.fileno()))
 PIPENV_SHELL_EXPLICIT = os.environ.get('PIPENV_SHELL')
 PIPENV_SHELL = os.environ.get('SHELL') or os.environ.get('PYENV_SHELL')
+PIPENV_EMULATOR = os.environ.get('PIPENV_EMULATOR')
 PIPENV_CACHE_DIR = os.environ.get('PIPENV_CACHE_DIR', user_cache_dir('pipenv'))
 # Tells pipenv to override PyPI index urls with a mirror.
 PIPENV_PYPI_MIRROR = os.environ.get('PIPENV_PYPI_MIRROR')