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Lib/site-packages/pipenv/vendor/plette/models/scripts.py

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+import re
+import shlex
+
+import six
+
+from .base import DataView
+
+
+class Script(DataView):
+    """Parse a script line (in Pipfile's [scripts] section).
+
+    This always works in POSIX mode, even on Windows.
+    """
+    # This extra layer is intentional. Cerberus does not allow validation of
+    # non-mapping inputs, so we wrap this in a top-level key. The Script model
+    # class implements extra hacks to make this work.
+    __SCHEMA__ = {
+        "__script__": {
+            "oneof_type": ["string", "list"], "required": True, "empty": False,
+            "schema": {"type": "string"},
+        },
+    }
+
+    def __init__(self, data):
+        super(Script, self).__init__(data)
+        if isinstance(data, six.string_types):
+            data = shlex.split(data)
+        self._parts = [data[0]]
+        self._parts.extend(data[1:])
+
+    @classmethod
+    def validate(cls, data):
+        # HACK: Make this validatable for Cerberus. See comments in validation
+        # side for more information.
+        return super(Script, cls).validate({"__script__": data})
+
+    def __repr__(self):
+        return "Script({0!r})".format(self._parts)
+
+    @property
+    def command(self):
+        return self._parts[0]
+
+    @property
+    def args(self):
+        return self._parts[1:]
+
+    def cmdify(self, extra_args=None):
+        """Encode into a cmd-executable string.
+
+        This re-implements CreateProcess's quoting logic to turn a list of
+        arguments into one single string for the shell to interpret.
+
+        * All double quotes are escaped with a backslash.
+        * Existing backslashes before a quote are doubled, so they are all
+          escaped properly.
+        * Backslashes elsewhere are left as-is; cmd will interpret them
+          literally.
+
+        The result is then quoted into a pair of double quotes to be grouped.
+
+        An argument is intentionally not quoted if it does not contain
+        whitespaces. This is done to be compatible with Windows built-in
+        commands that don't work well with quotes, e.g. everything with `echo`,
+        and DOS-style (forward slash) switches.
+
+        The intended use of this function is to pre-process an argument list
+        before passing it into ``subprocess.Popen(..., shell=True)``.
+
+        See also: https://docs.python.org/3/library/subprocess.html
+        """
+        parts = list(self._parts)
+        if extra_args:
+            parts.extend(extra_args)
+        return " ".join(
+            arg if not next(re.finditer(r'\s', arg), None)
+            else '"{0}"'.format(re.sub(r'(\\*)"', r'\1\1\\"', arg))
+            for arg in parts
+        )