Fix bash completion for COMP_WORDBREAKS characters like colon

Rebuild COMP_WORDS from COMP_LINE before dispatching to Typer and strip the wordbreak prefix from candidates so values like alpine:latest complete correctly instead of returning empty or duplicating alpine:.

Author: yoshibase

tests/test_completion/test_completion_bash_wordbreaks.py

@@ -0,0 +1,92 @@
+import os
+import shutil
+import stat
+import subprocess
+import sys
+import tempfile
+from pathlib import Path
+
+from . import colon_example as mod
+
+from ..utils import needs_bash
+
+
+def _bash_completion_reply(
+  script: str,
+  *,
+  wrapper_dir: Path,
+  comp_line: str,
+  comp_words: str,
+  comp_cword: str,
+) -> str:
+  bash = shutil.which("bash")
+  if bash is None:
+    raise RuntimeError("bash not found")
+  with tempfile.NamedTemporaryFile("w", suffix=".sh", delete=False) as handle:
+    handle.write(
+      f"""
+set -euo pipefail
+export PATH={wrapper_dir}:{os.environ.get("PATH", "")}
+{script}
+COMP_LINE={comp_line!r}
+COMP_POINT=${{#COMP_LINE}}
+COMP_WORDS=({comp_words})
+COMP_CWORD={comp_cword}
+_colon_examplepy_completion colon_example.py
+printf '%s\\n' "${{COMPREPLY[@]}}"
+"""
+    )
+    path = handle.name
+  try:
+    result = subprocess.run(
+      [bash, "--norc", path],
+      capture_output=True,
+      encoding="utf-8",
+      env={**os.environ, "PYTHONPATH": os.pathsep.join(sys.path)},
+    )
+  finally:
+    Path(path).unlink(missing_ok=True)
+  assert result.returncode == 0, result.stderr
+  return result.stdout
+
+
+@needs_bash
+def test_bash_completion_script_handles_comp_wordbreaks_colon() -> None:
+  show = subprocess.run(
+    [
+      sys.executable,
+      "-m",
+      "coverage",
+      "run",
+      mod.__file__,
+      "--show-completion",
+      "bash",
+    ],
+    capture_output=True,
+    encoding="utf-8",
+    env={
+      **os.environ,
+      "_TYPER_COMPLETE_TEST_DISABLE_SHELL_DETECTION": "True",
+    },
+  )
+  assert show.returncode == 0
+  assert "COMP_LINE" in show.stdout
+  assert "COMP_WORDBREAKS" in show.stdout
+
+  with tempfile.TemporaryDirectory() as tmp:
+    wrapper_dir = Path(tmp)
+    wrapper = wrapper_dir / "colon_example.py"
+    wrapper.write_text(
+      f"#!/bin/sh\nexec {sys.executable} -m coverage run {mod.__file__} \"$@\"\n"
+    )
+    wrapper.chmod(wrapper.stat().st_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH)
+
+    reply = _bash_completion_reply(
+      show.stdout,
+      wrapper_dir=wrapper_dir,
+      comp_line="colon_example.py --name alpine:l",
+      comp_words="colon_example.py --name : l",
+      comp_cword="3",
+    )
+  assert "latest" in reply.splitlines()
+  assert "alpine:latest" not in reply

typer/_completion_shared.py

@@ -20,10 +20,26 @@ class Shells(str, Enum):
 
 COMPLETION_SCRIPT_BASH = """
 %(complete_func)s() {
+    local __line=${COMP_LINE:0:COMP_POINT}
+    local -a __words
+    read -ra __words <<< "$__line"
+    local __cword=${#__words[@]}
+    [[ $__line != *[[:space:]] ]] && __cword=$((__cword - 1))
+    local __full=${__words[__cword]-}
+
     local IFS=$'\n'
-    COMPREPLY=( $( env COMP_WORDS="${COMP_WORDS[*]}" \\
-                   COMP_CWORD=$COMP_CWORD \\
+    local -a __raw
+    __raw=( $( env COMP_WORDS="${__words[*]}" \\
+                   COMP_CWORD=$__cword \\
                    %(autocomplete_var)s=complete_bash $1 ) )
+
+    local __cur=${__full##*[$COMP_WORDBREAKS]}
+    local __strip=$(( ${#__full} - ${#__cur} ))
+    COMPREPLY=()
+    local __c
+    for __c in "${__raw[@]}"; do
+        COMPREPLY+=( "${__c:__strip}" )
+    done
     return 0
 }