Document and test postparsing hooks

1 files changed, 179 insertions, 0 deletions

diff --git a/tests/test_plugin.py b/tests/test_plugin.py
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+++ b/tests/test_plugin.py
@@ -0,0 +1,179 @@
+# coding=utf-8
+"""
+Test plugin infrastructure and hooks.
+
+Copyright 2018 Jared Crapo <jared@kotfu.net>
+Released under MIT license, see LICENSE file
+"""
+
+from typing import Tuple
+
+import pytest
+
+import cmd2
+
+from .conftest import StdOut
+
+class Plugin:
+    "A mixin class for testing hook registration and calling"
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.reset_counters()
+
+    def reset_counters(self):
+        self.called_pph = 0
+
+    def pph(self, statement: cmd2.Statement) -> Tuple[bool, cmd2.Statement]:
+        self.called_pph += 1
+        return False, statement
+
+    def pph_stop(self, statement: cmd2.Statement) -> Tuple[bool, cmd2.Statement]:
+        self.called_pph += 1
+        return True, statement
+
+    def pph_emptystatement(self, statement: cmd2.Statement) -> Tuple[bool, cmd2.Statement]:
+        self.called_pph += 1
+        raise cmd2.EmptyStatement
+
+    def pph_exception(self, statement: cmd2.Statement) -> Tuple[bool, cmd2.Statement]:
+        self.called_pph += 1
+        raise ValueError
+
+class PluggedApp(Plugin, cmd2.Cmd):
+    "A sample app with a plugin mixed in"
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+    def do_say(self, statement):
+        """Repeat back the arguments"""
+        self.poutput(statement)
+
+###
+#
+# test hooks
+#
+###
+def test_postparsing_hook(capsys):
+    app = PluggedApp()
+    app.onecmd_plus_hooks('say hello')
+    out, err = capsys.readouterr()
+    assert out == 'hello\n'
+    assert not err
+    assert not app.called_pph
+
+    app.reset_counters()
+    app.register_postparsing_hook(app.pph)
+    app.onecmd_plus_hooks('say hello')
+    out, err = capsys.readouterr()
+    assert out == 'hello\n'
+    assert not err
+    assert app.called_pph == 1
+
+    # register the function again, so it should be called
+    # twice
+    app.reset_counters()
+    app.register_postparsing_hook(app.pph)
+    app.onecmd_plus_hooks('say hello')
+    out, err = capsys.readouterr()
+    assert out == 'hello\n'
+    assert not err
+    assert app.called_pph == 2
+
+def test_postparsing_hook_stop_first(capsys):
+    app = PluggedApp()
+    app.register_postparsing_hook(app.pph_stop)
+    stop = app.onecmd_plus_hooks('say hello')
+    assert app.called_pph == 1
+    assert stop
+
+    # register another function but it shouldn't be called
+    app.reset_counters()
+    app.register_postparsing_hook(app.pph)
+    stop = app.onecmd_plus_hooks('say hello')
+    assert app.called_pph == 1
+    assert stop
+
+def test_postparsing_hook_stop_second(capsys):
+    app = PluggedApp()
+    app.register_postparsing_hook(app.pph)
+    stop = app.onecmd_plus_hooks('say hello')
+    assert app.called_pph == 1
+    assert not stop
+
+    # register another function and make sure it gets called
+    app.reset_counters()
+    app.register_postparsing_hook(app.pph_stop)
+    stop = app.onecmd_plus_hooks('say hello')
+    assert app.called_pph == 2
+    assert stop
+
+    # register a third function which shouldn't be called
+    app.reset_counters()
+    app.register_postparsing_hook(app.pph)
+    stop = app.onecmd_plus_hooks('say hello')
+    assert app.called_pph == 2
+    assert stop
+
+def test_postparsing_hook_emptystatement_first(capsys):
+    app = PluggedApp()
+    app.register_postparsing_hook(app.pph_emptystatement)
+    app.onecmd_plus_hooks('say hello')
+    out, err = capsys.readouterr()
+    assert not out
+    assert not err
+    assert app.called_pph == 1
+
+    # register another function but it shouldn't be called
+    app.reset_counters()
+    app.register_postparsing_hook(app.pph)
+    app.onecmd_plus_hooks('say hello')
+    out, err = capsys.readouterr()
+    assert not out
+    assert not err
+    assert app.called_pph == 1
+
+def test_postparsing_hook_emptystatement_second(capsys):
+    app = PluggedApp()
+    app.register_postparsing_hook(app.pph)
+    app.onecmd_plus_hooks('say hello')
+    out, err = capsys.readouterr()
+    assert out == 'hello\n'
+    assert not err
+    assert app.called_pph == 1
+
+    # register another function and make sure it gets called
+    app.reset_counters()
+    app.register_postparsing_hook(app.pph_emptystatement)
+    app.onecmd_plus_hooks('say hello')
+    out, err = capsys.readouterr()
+    assert not out
+    assert not err
+    assert app.called_pph == 2
+
+    # register a third function which shouldn't be called
+    app.reset_counters()
+    app.register_postparsing_hook(app.pph)
+    stop = app.onecmd_plus_hooks('say hello')
+    out, err = capsys.readouterr()
+    assert not out
+    assert not err
+    assert app.called_pph == 2
+    assert not stop
+
+def test_postparsing_hook_exception(capsys):
+    app = PluggedApp()
+    app.register_postparsing_hook(app.pph_exception)
+    app.onecmd_plus_hooks('say hello')
+    out, err = capsys.readouterr()
+    assert not out
+    assert err
+    assert app.called_pph == 1
+
+    # register another function, but it shouldn't be called
+    app.reset_counters()
+    app.register_postparsing_hook(app.pph)
+    app.onecmd_plus_hooks('say hello')
+    out, err = capsys.readouterr()
+    assert not out
+    assert err
+    assert app.called_pph == 1