[sans-io] add Layer tests

mitmproxy/proxy2/layer.py

@@ -52,7 +52,7 @@ class Layer:
                         log.log_tier(context.options.console_eventlog_verbosity) >= log.log_tier("debug")
                 )
         )
-        if show_debug_output:
+        if show_debug_output:  # pragma: no cover
             self.debug = "  " * len(context.layers)
 
     def __repr__(self):

test/mitmproxy/proxy2/test_layer.py

@@ -4,13 +4,63 @@ from mitmproxy.proxy2 import commands, events, layer
 from test.mitmproxy.proxy2 import tutils
 
 
+class TestLayer:
+    def test_debug_messages(self, tctx):
+        tctx.server.id = "serverid"
+
+        class TLayer(layer.Layer):
+            debug = " "
+
+            def _handle_event(self, event: events.Event) -> layer.CommandGenerator[None]:
+                yield from self.state(event)
+
+            def state_foo(self, event: events.Event) -> layer.CommandGenerator[None]:
+                assert isinstance(event, events.Start)
+                yield commands.OpenConnection(self.context.server)
+                self.state = self.state_bar
+
+            state = state_foo
+
+            def state_bar(self, event: events.Event) -> layer.CommandGenerator[None]:
+                assert isinstance(event, events.DataReceived)
+                yield commands.Log("baz", "info")
+
+        tlayer = TLayer(tctx)
+        assert (
+                tutils.Playbook(tlayer, hooks=True, logs=True)
+                << commands.Log(" >> Start({})", "debug")
+                << commands.Log(" << OpenConnection({'connection': Server({'id': 'serverid', 'address': None})})",
+                                "debug")
+                << commands.OpenConnection(tctx.server)
+                >> events.DataReceived(tctx.client, b"foo")
+                << commands.Log(" >! DataReceived(client, b'foo')", "debug")
+                >> tutils.reply(None, to=-3)
+                << commands.Log(" >> Reply(OpenConnection({'connection': Server("
+                                "{'id': 'serverid', 'address': None, 'state': <ConnectionState.OPEN: 3>})}))", "debug")
+                << commands.Log(" !> DataReceived(client, b'foo')", "debug")
+
+                << commands.Log("baz", "info")
+        )
+        assert repr(tlayer) == "TLayer(state: bar)"
+
+    def test_debug_shorten(self, tctx):
+        t = layer.Layer(tctx)
+        t.debug = "  "
+        assert t._Layer__debug("x" * 600).message == "  " + "x" * 512 + "…"
+        assert t._Layer__debug("x" * 600).message == "  " + "x" * 256 + "…"
+        assert t._Layer__debug("foo").message == "  foo"
+
+
 class TestNextLayer:
     def test_simple(self, tctx):
-        nl = layer.NextLayer(tctx)
+        nl = layer.NextLayer(tctx, ask_on_start=True)
+        nl.debug = "  "
         playbook = tutils.Playbook(nl, hooks=True)
 
         assert (
                 playbook
+                << layer.NextLayerHook(nl)
+                >> tutils.reply()
                 >> events.DataReceived(tctx.client, b"foo")
                 << layer.NextLayerHook(nl)
                 >> tutils.reply()