diff tests/test-wireproto-serverreactor.py @ 37058:c5e9c3b47366

wireproto: support for receiving multiple requests

Now that we have request IDs on each frame and a specification
that allows multiple requests to be issued simultaneously,
possibly interleaved, let's teach the server to deal with that.

Instead of tracking the state for *the* active command request,
we instead track the state of each receiving command by its
request ID. The multiple states in our state machine for processing
each command's state has been collapsed into a single state for
"receiving commands."

Tests have been added so our branch coverage covers all meaningful
branches.

However, we did lose some logical coverage. The implementation
of this new feature opens up the door to a server having partial
command requests when end of input is reached. We will probably
want a mechanism to deal with partial requests. For now, I've
tracked that as a known issue in the class docstring. I've
also noted an abuse vector that becomes a little bit easier to
exploit with this feature.

Differential Revision: https://phab.mercurial-scm.org/D2870

--- a/tests/test-wireproto-serverreactor.py	Wed Mar 14 16:51:34 2018 -0700
+++ b/tests/test-wireproto-serverreactor.py	Wed Mar 14 16:53:30 2018 -0700
@@ -196,6 +196,19 @@
             'message': b'expected command frame; got 2',
         })
 
+    def testunexpectedcommandargumentreceiving(self):
+        """Same as above but the command is receiving."""
+        results = list(sendframes(makereactor(), [
+            ffs(b'1 command-name have-data command'),
+            ffs(b'1 command-argument eoa ignored'),
+        ]))
+
+        self.assertaction(results[1], 'error')
+        self.assertEqual(results[1][1], {
+            'message': b'received command argument frame for request that is '
+                       b'not expecting arguments: 1',
+        })
+
     def testunexpectedcommanddata(self):
         """Command argument frame when not running a command is an error."""
         result = self._sendsingleframe(makereactor(),
@@ -205,6 +218,19 @@
             'message': b'expected command frame; got 3',
         })
 
+    def testunexpectedcommanddatareceiving(self):
+        """Same as above except the command is receiving."""
+        results = list(sendframes(makereactor(), [
+            ffs(b'1 command-name have-args command'),
+            ffs(b'1 command-data eos ignored'),
+        ]))
+
+        self.assertaction(results[1], 'error')
+        self.assertEqual(results[1][1], {
+            'message': b'received command data frame for request that is not '
+                       b'expecting data: 1',
+        })
+
     def testmissingcommandframeflags(self):
         """Command name frame must have flags set."""
         result = self._sendsingleframe(makereactor(),
@@ -214,19 +240,77 @@
             'message': b'missing frame flags on command frame',
         })
 
+    def testconflictingrequestid(self):
+        """Multiple fully serviced commands with same request ID is allowed."""
+        results = list(sendframes(makereactor(), [
+            ffs(b'1 command-name eos command'),
+            ffs(b'1 command-name eos command'),
+            ffs(b'1 command-name eos command'),
+        ]))
+        for i in range(3):
+            self.assertaction(results[i], 'runcommand')
+            self.assertEqual(results[i][1], {
+                'requestid': 1,
+                'command': b'command',
+                'args': {},
+                'data': None,
+            })
+
+    def testconflictingrequestid(self):
+        """Request ID for new command matching in-flight command is illegal."""
+        results = list(sendframes(makereactor(), [
+            ffs(b'1 command-name have-args command'),
+            ffs(b'1 command-name eos command'),
+        ]))
+
+        self.assertaction(results[0], 'wantframe')
+        self.assertaction(results[1], 'error')
+        self.assertEqual(results[1][1], {
+            'message': b'request with ID 1 already received',
+        })
+
+    def testinterleavedcommands(self):
+        results = list(sendframes(makereactor(), [
+            ffs(b'1 command-name have-args command1'),
+            ffs(b'3 command-name have-args command3'),
+            ffs(br'1 command-argument 0 \x03\x00\x03\x00foobar'),
+            ffs(br'3 command-argument 0 \x03\x00\x03\x00bizbaz'),
+            ffs(br'3 command-argument eoa \x03\x00\x03\x00keyval'),
+            ffs(br'1 command-argument eoa \x04\x00\x03\x00key1val'),
+        ]))
+
+        self.assertEqual([t[0] for t in results], [
+            'wantframe',
+            'wantframe',
+            'wantframe',
+            'wantframe',
+            'runcommand',
+            'runcommand',
+        ])
+
+        self.assertEqual(results[4][1], {
+            'requestid': 3,
+            'command': 'command3',
+            'args': {b'biz': b'baz', b'key': b'val'},
+            'data': None,
+        })
+        self.assertEqual(results[5][1], {
+            'requestid': 1,
+            'command': 'command1',
+            'args': {b'foo': b'bar', b'key1': b'val'},
+            'data': None,
+        })
+
     def testmissingargumentframe(self):
+        # This test attempts to test behavior when reactor has an incomplete
+        # command request waiting on argument data. But it doesn't handle that
+        # scenario yet. So this test does nothing of value.
         frames = [
             ffs(b'1 command-name have-args command'),
-            ffs(b'1 command-name 0 ignored'),
         ]
 
         results = list(sendframes(makereactor(), frames))
-        self.assertEqual(len(results), 2)
         self.assertaction(results[0], 'wantframe')
-        self.assertaction(results[1], 'error')
-        self.assertEqual(results[1][1], {
-            'message': b'expected command argument frame; got 1',
-        })
 
     def testincompleteargumentname(self):
         """Argument frame with incomplete name."""
@@ -259,17 +343,16 @@
         })
 
     def testmissingcommanddataframe(self):
+        # The reactor doesn't currently handle partially received commands.
+        # So this test is failing to do anything with request 1.
         frames = [
             ffs(b'1 command-name have-data command1'),
-            ffs(b'1 command-name eos command2'),
+            ffs(b'3 command-name eos command2'),
         ]
         results = list(sendframes(makereactor(), frames))
         self.assertEqual(len(results), 2)
         self.assertaction(results[0], 'wantframe')
-        self.assertaction(results[1], 'error')
-        self.assertEqual(results[1][1], {
-            'message': b'expected command data frame; got 1',
-        })
+        self.assertaction(results[1], 'runcommand')
 
     def testmissingcommanddataframeflags(self):
         frames = [
@@ -284,6 +367,18 @@
             'message': b'command data frame without flags',
         })
 
+    def testframefornonreceivingrequest(self):
+        """Receiving a frame for a command that is not receiving is illegal."""
+        results = list(sendframes(makereactor(), [
+            ffs(b'1 command-name eos command1'),
+            ffs(b'3 command-name have-data command3'),
+            ffs(b'1 command-argument eoa ignored'),
+        ]))
+        self.assertaction(results[2], 'error')
+        self.assertEqual(results[2][1], {
+            'message': b'received frame for request that is not receiving: 1',
+        })
+
     def testsimpleresponse(self):
         """Bytes response to command sends result frames."""
         reactor = makereactor()