Handle Abort/Exit during shell completion

tests/test_shell_completion_abort_exit.py

@@ -0,0 +1,65 @@
+import click
+import pytest
+from typer.completion import shell_complete
+
+
+class _FakeCompletion:
+    def __init__(self, cli, ctx_args, prog_name, complete_var):
+        self.cli = cli
+        self.ctx_args = ctx_args
+        self.prog_name = prog_name
+        self.complete_var = complete_var
+
+    def source(self):
+        # This will be overridden per-test via monkeypatch on the class
+        return ""
+
+    def complete(self):
+        # This will be overridden per-test via monkeypatch on the class
+        return ""
+
+
+@pytest.mark.parametrize(
+    "instruction",
+    ["complete_zsh", "source_zsh"],
+)
+@pytest.mark.parametrize(
+    "exc",
+    [click.exceptions.Abort, click.exceptions.Exit],
+)
+def test_shell_complete_handles_abort_and_exit(monkeypatch, capsys, instruction, exc):
+    monkeypatch.setattr(
+        click.shell_completion,
+        "get_completion_class",
+        lambda shell: _FakeCompletion,
+    )
+
+    if instruction.startswith("complete"):
+        monkeypatch.setattr(
+            _FakeCompletion, "complete", lambda self: (_ for _ in ()).throw(exc())
+        )
+    else:
+        monkeypatch.setattr(
+            _FakeCompletion, "source", lambda self: (_ for _ in ()).throw(exc())
+        )
+
+    cli = click.Command("demo")
+
+    code = shell_complete(
+        cli=cli,
+        ctx_args={},
+        prog_name="demo",
+        complete_var="_DEMO_COMPLETE",
+        instruction=instruction,
+    )
+
+    out = capsys.readouterr()
+    assert code == 0
+    assert out.out == ""
+    assert out.err == ""
+
+
+def test_fake_completion_default_methods_are_covered():
+    fc = _FakeCompletion(click.Command("demo"), {}, "demo", "_DEMO_COMPLETE")
+    assert fc.complete() == ""
+    assert fc.source() == ""

typer/completion.py

@@ -134,12 +134,22 @@ def shell_complete(
     comp = comp_cls(cli, ctx_args, prog_name, complete_var)
 
     if instruction == "source":
-        click.echo(comp.source())
+        try:
+            click.echo(comp.source())
+        except (click.exceptions.Abort, click.exceptions.Exit):
+            # During shell completion we should never show a traceback.
+            # If completion callbacks abort/exit, just return no output.
+            return 0
         return 0
 
     # Typer override to print the completion help msg with Rich
     if instruction == "complete":
-        click.echo(comp.complete())
+        try:
+            click.echo(comp.complete())
+        except (click.exceptions.Abort, click.exceptions.Exit):
+            # During shell completion we should never show a traceback.
+            # If completion callbacks abort/exit, just return no output.
+            return 0
         return 0
     # Typer override end