Add support for CLI tab completions

README.md

@@ -252,6 +252,33 @@ WSL-based installation.
 See [here](INSTALL_FROM_SOURCE.md).
 
 
+## Shell Tab Completion
+
+Tab completion is available for the following shells: Bash, Zsh, and Tcsh.
+
+To enable tab completion, run the following command to generate the appropriate script:
+
+```bash
+fairseq2 --print-completion {bash|zsh|tcsh}
+```
+
+You can either save the output to the shell's completion directory for permanent use or apply it directly to your current session.
+
+For example, to enable Bash completion for the current session, use:
+```bash
+eval "$(fairseq2 --print-completion bash)"
+```
+
+For a permanent setup, run the following command to store the completion script:
+```bash
+echo "eval $(fairseq2 --print-completion bash)" >> "$BASH_COMPLETION_COMPAT_DIR/shtab"
+```
+
+Here, `BASH_COMPLETION_COMPAT_DIR` is the path to your system's shell completion directory.
+
+This ensures that tab completion will be enabled every time you start a new shell session.
+
+
 ## Contributing
 We always welcome contributions to fairseq2! Please refer to
 [Contribution Guidelines](CONTRIBUTING.md) to learn how to format, test, and

setup.py

@@ -62,6 +62,7 @@
         "torcheval~=0.0.6",
         "tqdm~=4.62",
         "typing_extensions~=4.12",
+        "shtab~=1.7",
     ],
     extras_require={
         "arrow": ["pyarrow>=13.0.0", "pandas~=2.0.0"],

src/fairseq2/recipes/cli.py

@@ -16,6 +16,7 @@
 from types import FrameType
 from typing import Generic, Protocol, TypeVar, final, runtime_checkable
 
+import shtab
 import yaml
 from rich.console import Console
 from typing_extensions import override
@@ -139,6 +140,7 @@ def __call__(self) -> None:
 
     def _run_command(self) -> None:
         parser = ArgumentParser(self._name, description=self._description)
+        shtab.add_argument_to(parser, ["-s", "--print-completion"])
 
         self.init_parser(parser)
 
@@ -484,7 +486,7 @@ def init_parser(self, parser: ArgumentParser) -> None:
             type=Path,
             nargs="*",
             help="yaml configuration file(s)",
-        )
+        ).complete = shtab.FILE  # type: ignore[attr-defined]
 
         parser.add_argument(
             "--config",
@@ -527,7 +529,7 @@ def init_parser(self, parser: ArgumentParser) -> None:
             type=Path,
             nargs=OPTIONAL,
             help="directory to store recipe artifacts",
-        )
+        ).complete = shtab.DIRECTORY  # type: ignore[attr-defined]
 
     @override
     def __call__(self, args: Namespace) -> None:

src/fairseq2/recipes/llama/convert_checkpoint.py

@@ -15,6 +15,7 @@
 from typing import final
 from warnings import catch_warnings
 
+import shtab
 from typing_extensions import override
 
 from fairseq2.console import get_error_console
@@ -43,13 +44,13 @@ def init_parser(self, parser: ArgumentParser) -> None:
             "input_dir",
             type=Path,
             help="checkpoint directory",
-        )
+        ).complete = shtab.DIRECTORY  # type: ignore[attr-defined]
 
         parser.add_argument(
             "output_dir",
             type=Path,
             help="output directory to store reference checkpoint",
-        )
+        ).complete = shtab.DIRECTORY  # type: ignore[attr-defined]
 
     @override
     def __call__(self, args: Namespace) -> None: