From 35550e048bde73b08fad28c2a8d844dcbdea7f35 Mon Sep 17 00:00:00 2001
From: Todd Leonhardt <todd.leonhardt@gmail.com>
Date: Sun, 23 Sep 2018 18:51:30 -0400
Subject: Fixed several hack classes build to simulate file descriptors

Now there is a single class, StdSim in utils.py, which is intended to simulate stdout and stderr file objects.

This class replaced the following:
- pyscript_bridge.py::CopyStream
- transcript.py::OutputTrap
- conftest.py::StdOut
---
 cmd2/utils.py | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

(limited to 'cmd2/utils.py')

diff --git a/cmd2/utils.py b/cmd2/utils.py
index 735221c8..83185603 100644
--- a/cmd2/utils.py
+++ b/cmd2/utils.py
@@ -246,3 +246,57 @@ def natural_sort(list_to_sort: List[str]) -> List[str]:
     :return: the list sorted naturally
     """
     return sorted(list_to_sort, key=natural_keys)
+
+
+class StdSim(object):
+    """Class to simulate behavior of sys.stdout or sys.stderr.
+
+    Stores contents in internal buffer and optionally echos to the inner stream it is simulating.
+    """
+    class ByteBuf(object):
+        """Inner class which stores an actual bytes buffer and does the actual output if echo is enabled."""
+        def __init__(self, inner_stream, echo: bool = False) -> None:
+            self.byte_buf = b''
+            self.inner_stream = inner_stream
+            self.echo = echo
+
+        def write(self, b: bytes) -> None:
+            """Add bytes to internal bytes buffer and if echo is True, echo contents to inner stream."""
+            self.byte_buf += b
+            if self.echo:
+                self.inner_stream.buffer.write(b)
+
+    def __init__(self, inner_stream, echo: bool = False) -> None:
+        self.buffer = self.ByteBuf(inner_stream, echo)
+        self.inner_stream = inner_stream
+
+    def write(self, s: str) -> None:
+        """Add str to internal bytes buffer and if echo is True, echo contents to inner stream."""
+        b = s.encode()
+        self.buffer.write(b)
+
+    def getvalue(self) -> str:
+        """Get the internal contents as a str.
+
+        :return string from the internal contents
+        """
+        return self.buffer.byte_buf.decode()
+
+    def read(self) -> str:
+        """Read from the internal contents as a str and then clear them out.
+
+        :return: string from the internal contents
+        """
+        result = self.getvalue()
+        self.clear()
+        return result
+
+    def clear(self) -> None:
+        """Clear the internal contents."""
+        self.buffer.byte_buf = b''
+
+    def __getattr__(self, item: str):
+        if item in self.__dict__:
+            return self.__dict__[item]
+        else:
+            return getattr(self.inner_stream, item)
-- 
cgit v1.2.1


From ca4ac5cfe4fae041463674cd8ee40b62444693f8 Mon Sep 17 00:00:00 2001
From: Todd Leonhardt <todd.leonhardt@gmail.com>
Date: Mon, 24 Sep 2018 09:49:46 -0400
Subject: StdSim write methods now raise a TypeError exception if passed the
 wrong type

Also:
- Added explicit unit tests for StdSim to test_utils.py
---
 cmd2/utils.py | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'cmd2/utils.py')

diff --git a/cmd2/utils.py b/cmd2/utils.py
index 83185603..bdb488cc 100644
--- a/cmd2/utils.py
+++ b/cmd2/utils.py
@@ -262,6 +262,8 @@ class StdSim(object):
 
         def write(self, b: bytes) -> None:
             """Add bytes to internal bytes buffer and if echo is True, echo contents to inner stream."""
+            if not isinstance(b, bytes):
+                raise TypeError('a bytes-like object is required, not {}'.format(type(b)))
             self.byte_buf += b
             if self.echo:
                 self.inner_stream.buffer.write(b)
@@ -272,6 +274,8 @@ class StdSim(object):
 
     def write(self, s: str) -> None:
         """Add str to internal bytes buffer and if echo is True, echo contents to inner stream."""
+        if not isinstance(s, str):
+            raise TypeError('write() argument must be str, not {}'.format(type(s)))
         b = s.encode()
         self.buffer.write(b)
 
-- 
cgit v1.2.1