Add color / non-color tests

tests/babi_test.py

@@ -1,4 +1,5 @@
 import contextlib
+import shlex
 import sys
 
 from hecate import Runner
@@ -7,8 +8,11 @@ import babi
 
 
 @contextlib.contextmanager
-def run(*args, **kwargs):
+def run(*args, color=True, **kwargs):
     cmd = (sys.executable, '-mcoverage', 'run', '-m', 'babi', *args)
+    quoted = ' '.join(shlex.quote(p) for p in cmd)
+    term = 'screen-256color' if color else 'screen'
+    cmd = ('bash', '-c', f'export TERM={term}; exec {quoted}')
     with Runner(*cmd, **kwargs) as h:
         h.await_text(babi.VERSION_STR)
         yield h
@@ -24,6 +28,12 @@ def await_text_missing(h, text):
     raise AssertionError(f'Timeout while waiting for text {text!r} to appear')
 
 
+def test_can_start_without_color():
+    with run(color=False) as h:
+        h.press('C-x')
+        h.await_exit()
+
+
 def test_window_bounds(tmpdir):
     f = tmpdir.join('f.txt')
     f.write(f'{"x" * 40}\n' * 40)