1 files changed, 118 insertions, 0 deletions
diff --git a/src/prompt_toolkit/input/posix_pipe.py b/src/prompt_toolkit/input/posix_pipe.py
new file mode 100644
index 0000000..c131fb8
--- /dev/null
+++ b/src/prompt_toolkit/input/posix_pipe.py
@@ -0,0 +1,118 @@
+from __future__ import annotations
+
+import sys
+
+assert sys.platform != "win32"
+
+import os
+from contextlib import contextmanager
+from typing import ContextManager, Iterator, TextIO, cast
+
+from ..utils import DummyContext
+from .base import PipeInput
+from .vt100 import Vt100Input
+
+__all__ = [
+    "PosixPipeInput",
+]
+
+
+class _Pipe:
+    "Wrapper around os.pipe, that ensures we don't double close any end."
+
+    def __init__(self) -> None:
+        self.read_fd, self.write_fd = os.pipe()
+        self._read_closed = False
+        self._write_closed = False
+
+    def close_read(self) -> None:
+        "Close read-end if not yet closed."
+        if self._read_closed:
+            return
+
+        os.close(self.read_fd)
+        self._read_closed = True
+
+    def close_write(self) -> None:
+        "Close write-end if not yet closed."
+        if self._write_closed:
+            return
+
+        os.close(self.write_fd)
+        self._write_closed = True
+
+    def close(self) -> None:
+        "Close both read and write ends."
+        self.close_read()
+        self.close_write()
+
+
+class PosixPipeInput(Vt100Input, PipeInput):
+    """
+    Input that is send through a pipe.
+    This is useful if we want to send the input programmatically into the
+    application. Mostly useful for unit testing.
+
+    Usage::
+
+        with PosixPipeInput.create() as input:
+            input.send_text('inputdata')
+    """
+
+    _id = 0
+
+    def __init__(self, _pipe: _Pipe, _text: str = "") -> None:
+        # Private constructor. Users should use the public `.create()` method.
+        self.pipe = _pipe
+
+        class Stdin:
+            encoding = "utf-8"
+
+            def isatty(stdin) -> bool:
+                return True
+
+            def fileno(stdin) -> int:
+                return self.pipe.read_fd
+
+        super().__init__(cast(TextIO, Stdin()))
+        self.send_text(_text)
+
+        # Identifier for every PipeInput for the hash.
+        self.__class__._id += 1
+        self._id = self.__class__._id
+
+    @classmethod
+    @contextmanager
+    def create(cls, text: str = "") -> Iterator[PosixPipeInput]:
+        pipe = _Pipe()
+        try:
+            yield PosixPipeInput(_pipe=pipe, _text=text)
+        finally:
+            pipe.close()
+
+    def send_bytes(self, data: bytes) -> None:
+        os.write(self.pipe.write_fd, data)
+
+    def send_text(self, data: str) -> None:
+        "Send text to the input."
+        os.write(self.pipe.write_fd, data.encode("utf-8"))
+
+    def raw_mode(self) -> ContextManager[None]:
+        return DummyContext()
+
+    def cooked_mode(self) -> ContextManager[None]:
+        return DummyContext()
+
+    def close(self) -> None:
+        "Close pipe fds."
+        # Only close the write-end of the pipe. This will unblock the reader
+        # callback (in vt100.py > _attached_input), which eventually will raise
+        # `EOFError`. If we'd also close the read-end, then the event loop
+        # won't wake up the corresponding callback because of this.
+        self.pipe.close_write()
+
+    def typeahead_hash(self) -> str:
+        """
+        This needs to be unique for every `PipeInput`.
+        """
+        return f"pipe-input-{self._id}"