cliutil: Add bytes_output() and text_output() functions.

conservancy_beancount/cliutil.py

@@ -19,6 +19,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>."""
 import argparse
 import enum
 import inspect
+import io
 import logging
 import operator
 import os
@@ -36,8 +37,11 @@ from . import filters
 from . import rtutil
 
 from typing import (
+    cast,
     Any,
+    BinaryIO,
     Callable,
+    IO,
     Iterable,
     NamedTuple,
     NoReturn,
@@ -51,6 +55,9 @@ from .beancount_types import (
     MetaKey,
 )
 
+OutputFile = Union[int, IO]
+
+STDSTREAM_PATH = Path('-')
 VERSION = pkg_resources.require(PKGNAME)[0].version
 
 class ExceptHook:
@@ -247,3 +254,51 @@ def setup_logger(logger: Union[str, logging.Logger]='',
     logger.addHandler(handler)
     logger.setLevel(loglevel)
     return logger
+
+def bytes_output(path: Optional[Path]=None,
+                 default: OutputFile=sys.stdout,
+                 mode: str='w',
+) -> BinaryIO:
+    """Get a file-like object suitable for binary output
+
+    If ``path`` is ``None`` or ``-``, returns a file-like object backed by
+    ``default``. If ``default`` is a file descriptor or text IO object, this
+    method returns a file-like object that writes to the same place.
+
+    Otherwise, returns ``path.open(mode)``.
+    """
+    mode = f'{mode}b'
+    if path is None or path == STDSTREAM_PATH:
+        if isinstance(default, int):
+            retval = open(default, mode)
+        elif isinstance(default, TextIO):
+            retval = default.buffer
+        else:
+            retval = default
+    else:
+        retval = path.open(mode)
+    return cast(BinaryIO, retval)
+
+def text_output(path: Optional[Path]=None,
+                default: OutputFile=sys.stdout,
+                mode: str='w',
+                encoding: Optional[str]=None,
+) -> TextIO:
+    """Get a file-like object suitable for text output
+
+    If ``path`` is ``None`` or ``-``, returns a file-like object backed by
+    ``default``. If ``default`` is a file descriptor or binary IO object, this
+    method returns a file-like object that writes to the same place.
+
+    Otherwise, returns ``path.open(mode)``.
+    """
+    if path is None or path == STDSTREAM_PATH:
+        if isinstance(default, int):
+            retval = open(default, mode, encoding=encoding)
+        elif isinstance(default, BinaryIO):
+            retval = io.TextIOWrapper(default, encoding=encoding)
+        else:
+            retval = default
+    else:
+        retval = path.open(mode, encoding=encoding)
+    return cast(TextIO, retval)

conservancy_beancount/reports/accrual.py

@@ -120,7 +120,6 @@ from .. import filters
 from .. import rtutil
 
 PROGNAME = 'accrual-report'
-STANDARD_PATH = Path('-')
 
 CompoundAmount = TypeVar('CompoundAmount', data.Amount, core.Balance)
 PostGroups = Mapping[Optional[MetaValue], 'AccrualPostings']
@@ -677,28 +676,6 @@ metadata to match. A single ticket number is a shortcut for
         args.report_type = ReportType.AGING
     return args
 
-def get_output_path(output_path: Optional[Path],
-                    default_path: Path=STANDARD_PATH,
-) -> Optional[Path]:
-    if output_path is None:
-        output_path = default_path
-    if output_path == STANDARD_PATH:
-        return None
-    else:
-        return output_path
-
-def get_output_bin(path: Optional[Path], stdout: TextIO) -> BinaryIO:
-    if path is None:
-        return open(stdout.fileno(), 'wb')
-    else:
-        return path.open('wb')
-
-def get_output_text(path: Optional[Path], stdout: TextIO) -> TextIO:
-    if path is None:
-        return stdout
-    else:
-        return path.open('w')
-
 def main(arglist: Optional[Sequence[str]]=None,
          stdout: TextIO=sys.stdout,
          stderr: TextIO=sys.stderr,
@@ -762,29 +739,26 @@ def main(arglist: Optional[Sequence[str]]=None,
             logger.error("unable to generate aging report: RT client is required")
         else:
             now = datetime.datetime.now()
-            default_path = Path(now.strftime('AgingReport_%Y-%m-%d_%H:%M.ods'))
+            if args.output_file is None:
-            output_path = get_output_path(args.output_file, default_path)
+                args.output_file = Path(now.strftime('AgingReport_%Y-%m-%d_%H:%M.ods'))
-            out_bin = get_output_bin(output_path, stdout)
+                logger.info("Writing report to %s", args.output_file)
+            out_bin = cliutil.bytes_output(args.output_file, stdout)
             report = AgingReport(rt_client, out_bin)
     elif args.report_type is ReportType.OUTGOING:
         rt_client = config.rt_client()
         if rt_client is None:
             logger.error("unable to generate outgoing report: RT client is required")
         else:
-            output_path = get_output_path(args.output_file)
+            out_file = cliutil.text_output(args.output_file, stdout)
-            out_file = get_output_text(output_path, stdout)
             report = OutgoingReport(rt_client, out_file)
     else:
-        output_path = get_output_path(args.output_file)
+        out_file = cliutil.text_output(args.output_file, stdout)
-        out_file = get_output_text(output_path, stdout)
         report = args.report_type.value(out_file)
 
     if report is None:
         returncode |= ReturnFlag.REPORT_ERRORS
     else:
         report.run(groups)
-        if args.output_file != output_path:
-            logger.info("Report saved to %s", output_path)
     return 0 if returncode == 0 else 16 + returncode
 
 if __name__ == '__main__':

tests/test_cliutil.py

@@ -21,12 +21,18 @@ import inspect
 import logging
 import os
 import re
+import sys
 import traceback
 
 import pytest
 
+from pathlib import Path
+
 from conservancy_beancount import cliutil
 
+FILE_NAMES = ['-foobar', '-foo.bin']
+STREAM_PATHS = [None, Path('-')]
+
 class AlwaysEqual:
     def __eq__(self, other):
         return True
@@ -57,6 +63,45 @@ def argparser():
     cliutil.add_version_argument(parser)
     return parser
 
+@pytest.mark.parametrize('path_name', FILE_NAMES)
+def test_bytes_output_path(path_name, tmp_path):
+    path = tmp_path / path_name
+    stream = io.BytesIO()
+    actual = cliutil.bytes_output(path, stream)
+    assert actual is not stream
+    assert str(actual.name) == str(path)
+    assert 'w' in actual.mode
+    assert 'b' in actual.mode
+
+@pytest.mark.parametrize('path', STREAM_PATHS)
+def test_bytes_output_stream(path):
+    stream = io.BytesIO()
+    actual = cliutil.bytes_output(path, stream)
+    assert actual is stream
+
+@pytest.mark.parametrize('func_name', [
+    'bytes_output',
+    'text_output',
+])
+def test_default_output(func_name):
+    actual = getattr(cliutil, func_name)()
+    assert actual.fileno() == sys.stdout.fileno()
+
+@pytest.mark.parametrize('path_name', FILE_NAMES)
+def test_text_output_path(path_name, tmp_path):
+    path = tmp_path / path_name
+    stream = io.StringIO()
+    actual = cliutil.text_output(path, stream)
+    assert actual is not stream
+    assert str(actual.name) == str(path)
+    assert 'w' in actual.mode
+
+@pytest.mark.parametrize('path', STREAM_PATHS)
+def test_text_output_stream(path):
+    stream = io.StringIO()
+    actual = cliutil.text_output(path, stream)
+    assert actual is stream
+
 @pytest.mark.parametrize('errnum', [
     errno.EACCES,
     errno.EPERM,