feat: handle better unhandled escape seq

Move the unhandled escape sequence check sooner to exec even if the test
fails by timeout (which it is likely if the output contains escape
sequences that makes the prompt or type regexps to fail and not match).

Add also a little of stats for introspection.

Author: eldipa

byexample/runner.py

@@ -1,5 +1,7 @@
 from __future__ import unicode_literals
 import pexpect, pexpect.popen_spawn, time, operator, os, itertools, contextlib
+
+import pprint
 import signal
 import subprocess
 from . import regex as re
@@ -197,6 +199,9 @@ def were_unhandled_escape_sequences(self):
     def reset_unhandled_state(self):
         self._were_unhandled_escape_sequences = False
 
+    def stats(self):
+        return self._screen.stats()
+
 
 class PopenSpawnExt(ReadFilter, pexpect.popen_spawn.PopenSpawn):
     ''' This is a compatibility layer that extends pexpect's PopenSpawn
@@ -584,29 +589,54 @@ def _exec_and_wait(self, source, options, *, from_example=None, **kargs):
             with log_with("sendlines") as clog2:
                 clog2.debug("\n > " + '\n > '.join(lines))
 
-        self._last_num_lines_sent = 0
-        for line in lines[:-1]:
+        try:
+            self._last_num_lines_sent = 0
+            for line in lines[:-1]:
+                with profile_ctx("sendline"):
+                    # turn the echo off (may be)
+                    self._may_turn_echo_off(options)
+
+                    self._sendline(line)
+                    self._last_num_lines_sent += 1
+                self._expect_prompt_or_type(
+                    options, countdown, input_list=input_list
+                )
+
             with profile_ctx("sendline"):
                 # turn the echo off (may be)
                 self._may_turn_echo_off(options)
 
-                self._sendline(line)
+                self._sendline(lines[-1])
                 self._last_num_lines_sent += 1
+
             self._expect_prompt_or_type(
-                options, countdown, input_list=input_list
+                options,
+                countdown,
+                prompt_re=self._PS1_re,
+                input_list=input_list
             )
+            self._expect_delayed_output(options)
+        finally:
+            unh = self._interpreter.were_unhandled_escape_sequences()
+
+            if from_example is not None and unh:
+                from_example.add_note_on_failure(
+                        "Escape/control sequences were detected. If the output looks\n" +\
+                        "scrambled or dirty, you may try a full terminal emulation with '+term=ansi'" +\
+                        ("\nRun byexample with -v to get more debugging details" if not clog().isEnabledFor(INFO) else "")
+                        )
+
+                if clog().isEnabledFor(INFO):
+                    from_example.add_note_on_failure(
+                        "Unhandled sequences: " + pprint.pformat(
+                            list(
+                                self._interpreter._screen.
+                                _unhandled_escape_seq_cnt.keys()
+                            )
+                        )
+                    )
 
-        with profile_ctx("sendline"):
-            # turn the echo off (may be)
-            self._may_turn_echo_off(options)
-
-            self._sendline(lines[-1])
-            self._last_num_lines_sent += 1
-
-        self._expect_prompt_or_type(
-            options, countdown, prompt_re=self._PS1_re, input_list=input_list
-        )
-        self._expect_delayed_output(options)
+            self._interpreter.reset_unhandled_state()
 
         if input_list:
             s = short_string(input_list[0][-1])
@@ -623,14 +653,6 @@ def _exec_and_wait(self, source, options, *, from_example=None, **kargs):
             with log_with("raw-got") as clog2:
                 clog2.debug("\n" + ''.join(self._output_between_prompts))
 
-        unh = self._interpreter.were_unhandled_escape_sequences()
-        self._interpreter.reset_unhandled_state()
-
-        if from_example is not None and unh:
-            from_example.add_note_on_failure(
-                    "Escape/control sequences were detected. If the output looks\n" +\
-                    "scrambled or dirty, you may try a full terminal emulation with '+term=ansi'"
-                    )
         out = self._get_output(options)
         return out