CLI: rephrase command and translate alias fail on every invocation #167

Two commands that the CLI advertises in --help cannot be used at all: both exit with status 1 before any request is sent to the API.

$ python -m deepl --help
...
    text (translate)   translate text(s)
    rephrase           rephrase text(s)

Environment

• deepl-python 1.32.0 (main at 74415f9); the code is unchanged since both were added in v1.21.0 (4107220)
• Python 3.11.15, Linux

Reproduction

No valid key or network access is needed, the failure happens before the HTTP call:

$ python -m deepl --auth-key x translate --to DE "proton beam"
Error: 'action_translate'
$ echo $?
1

$ python -m deepl --auth-key x rephrase --to EN-GB "proton beam"
Error: DeepLClient.rephrase_text() got an unexpected keyword argument 'show_detected_source'
$ echo $?
1

Expected

• translate behaves exactly like text, since it is registered as its alias.
• rephrase prints the improved text, and --show-detected-source additionally prints the detected source language, as it does for text.

Cause

Both are in deepl/__main__.py:

1. The text subparser is created with aliases=["translate"], so argparse stores command="translate". main() then dispatches with globals()[f"action_{command}"], and there is no action_translate function, so a KeyError is raised and printed as Error: 'action_translate'. (main() already special-cases "translate" a few lines above when reading the text from stdin, so the alias is clearly intended to work.)

2. The rephrase subparser defines --show-detected-source (action="store_true"), so show_detected_source is always present in the parsed arguments. action_rephrase() forwards all of them with deepl_client.rephrase_text(**kwargs), but rephrase_text() has no such parameter. action_text() avoids this by consuming show_detected_source itself; action_rephrase() does not, so the command fails whether or not the flag is passed.

tests/test_cli.py has no test for either rephrase or the translate alias, which is probably why this was not noticed.

Proposed fix

I have a small patch ready and can open a PR if you would like one (CONTRIBUTING asks for an issue first):

--- a/deepl/__main__.py
+++ b/deepl/__main__.py
@@ -116,6 +116,7 @@ def action_text(
 
 def action_rephrase(
     deepl_client: deepl.DeepLClient,
+    show_detected_source: bool = False,
     **kwargs,
 ):
     """Action function for the rephrase command."""
@@ -124,6 +125,10 @@ def action_rephrase(
         improvement if isinstance(improvement, List) else [improvement]
     )
     for output in output_list:
+        if show_detected_source:
+            print(
+                f"Detected source language: {output.detected_source_language}"
+            )
         print(output.text)
 
 
@@ -1054,6 +1059,9 @@ def main(args=None, prog_name=None):
         # Call action function corresponding to command with remaining args
         # ("translation-memory" maps to action_translation_memory).
         command = args.pop("command").replace("-", "_")
+        if command == "translate":
+            # "translate" is an alias of the "text" command
+            command = "text"
         globals()[f"action_{command}"](deepl_client, **args)

The patch also adds test_text_translate_alias, test_rephrase and test_rephrase_stdin to tests/test_cli.py. They fail on main and pass with the change when run against a local deepl-mock server; black --check ., flake8 deepl tests and mypy --exclude 'examples/' . are clean.