Move shell completion to the mvt command and generate one script for every MVT command

Setting up shell completion had nothing to do with the acquisition of one
platform, yet it was a command of mvt-ios and mvt-android, each
generating the script of the program it ran under only. Completion now
leaves the platform CLIs for mvt, which emits one script covering mvt,
mvt-ios and mvt-android, installed as a single file loaded when the shell
starts. Click names the completion function of each program after the
program, so the three scripts concatenate without colliding, and fish
takes the file in conf.d rather than one named after a single command.

With one script there is nothing left for the platform commands to
generate, so their completion command goes, and with it the banner
suppression which was keyed on the command name: mvt-ios and mvt-android
now print the banner for every command they have.

The long help line says which commands the completion covers, so a
short_help keeps "mvt --help" from truncating it.

tests/test_completion.py

@@ -6,56 +6,60 @@
 from click.testing import CliRunner
 
 from mvt.android.cli import cli as android_cli
+from mvt.cli import cli as mvt_cli
 from mvt.ios.cli import cli as ios_cli
 
 
 class TestCompletionCommand:
     def test_completion_prints_instructions_by_default(self):
         runner = CliRunner()
-        result = runner.invoke(ios_cli, ["completion"])
+        result = runner.invoke(mvt_cli, ["completion"])
 
         assert result.exit_code == 0
-        assert "Shell completion for mvt-ios" in result.output
-        assert "mvt-ios completion bash > ~/.mvt-ios-complete.bash" in result.output
+        assert "Shell completion for mvt, mvt-ios and mvt-android" in result.output
+        assert "mvt completion bash > ~/.mvt-complete.bash" in result.output
         assert "Mobile Verification Toolkit" not in result.output
 
-    def test_completion_prints_bash_script(self):
+    def test_completion_bash_script_covers_every_cli(self):
         runner = CliRunner()
-        result = runner.invoke(ios_cli, ["completion", "bash"])
+        result = runner.invoke(mvt_cli, ["completion", "bash"])
 
         assert result.exit_code == 0
+        assert "_MVT_COMPLETE=bash_complete" in result.output
         assert "_MVT_IOS_COMPLETE=bash_complete" in result.output
+        assert "_MVT_ANDROID_COMPLETE=bash_complete" in result.output
         assert "complete -o nosort" in result.output
-        assert "mvt-ios" in result.output
         assert "Mobile Verification Toolkit" not in result.output
 
-    def test_completion_prints_fish_script(self):
+    def test_completion_fish_script_covers_every_cli(self):
         runner = CliRunner()
-        result = runner.invoke(android_cli, ["completion", "fish"])
+        result = runner.invoke(mvt_cli, ["completion", "fish"])
 
         assert result.exit_code == 0
-        assert "_MVT_ANDROID_COMPLETE=fish_complete" in result.output
+        assert "complete --no-files --command mvt-ios" in result.output
         assert "complete --no-files --command mvt-android" in result.output
+        assert "complete --no-files --command mvt " in result.output
         assert "Mobile Verification Toolkit" not in result.output
 
     def test_completion_install_updates_bashrc_once(self, tmp_path, monkeypatch):
         monkeypatch.setenv("HOME", str(tmp_path))
         runner = CliRunner()
 
-        result = runner.invoke(ios_cli, ["completion", "bash", "--install"])
+        result = runner.invoke(mvt_cli, ["completion", "bash", "--install"])
         assert result.exit_code == 0
 
-        script_path = tmp_path / ".mvt-ios-complete.bash"
+        script_path = tmp_path / ".mvt-complete.bash"
         bashrc_path = tmp_path / ".bashrc"
         assert script_path.exists()
-        assert "_MVT_IOS_COMPLETE=bash_complete" in script_path.read_text(
-            encoding="utf-8"
-        )
+        script = script_path.read_text(encoding="utf-8")
+        assert "_MVT_COMPLETE=bash_complete" in script
+        assert "_MVT_IOS_COMPLETE=bash_complete" in script
+        assert "_MVT_ANDROID_COMPLETE=bash_complete" in script
         bashrc = bashrc_path.read_text(encoding="utf-8")
         assert "[ -f" in bashrc
-        assert ".mvt-ios-complete.bash" in bashrc
+        assert ".mvt-complete.bash" in bashrc
 
-        result = runner.invoke(ios_cli, ["completion", "bash", "--install"])
+        result = runner.invoke(mvt_cli, ["completion", "bash", "--install"])
         assert result.exit_code == 0
         assert bashrc_path.read_text(encoding="utf-8") == bashrc
 
@@ -65,14 +69,30 @@ class TestCompletionCommand:
         monkeypatch.setenv("HOME", str(tmp_path))
         runner = CliRunner()
 
-        result = runner.invoke(android_cli, ["completion", "fish", "--install"])
+        result = runner.invoke(mvt_cli, ["completion", "fish", "--install"])
 
         assert result.exit_code == 0
-        script_path = (
-            tmp_path / ".config" / "fish" / "completions" / "mvt-android.fish"
-        )
+        script_path = tmp_path / ".config" / "fish" / "conf.d" / "mvt-completion.fish"
         assert script_path.exists()
-        assert "_MVT_ANDROID_COMPLETE=fish_complete" in script_path.read_text(
-            encoding="utf-8"
-        )
+        script = script_path.read_text(encoding="utf-8")
+        assert "_MVT_COMPLETE=fish_complete" in script
+        assert "_MVT_IOS_COMPLETE=fish_complete" in script
+        assert "_MVT_ANDROID_COMPLETE=fish_complete" in script
         assert not (tmp_path / ".fishrc").exists()
+        assert not (tmp_path / ".bashrc").exists()
+        assert not (tmp_path / ".zshrc").exists()
+
+    def test_completion_install_without_shell_is_a_usage_error(self):
+        runner = CliRunner()
+        result = runner.invoke(mvt_cli, ["completion", "--install"])
+
+        assert result.exit_code == 2
+        assert "A shell is required when using --install." in result.output
+
+    def test_completion_is_not_a_command_of_the_platform_clis(self):
+        runner = CliRunner()
+
+        assert "completion" not in ios_cli.commands
+        assert "completion" not in android_cli.commands
+        assert runner.invoke(ios_cli, ["completion"]).exit_code == 2
+        assert runner.invoke(android_cli, ["completion"]).exit_code == 2