Merge pull request #307 from jdemeyer/none_delaybeforesend

Allow delaybeforesend=None to skip the sleep completely

3 files changed, 31 insertions, 4 deletions

diff --git a/doc/commonissues.rst b/doc/commonissues.rst
index d3aa9d0..f60085e 100644
--- a/doc/commonissues.rst
+++ b/doc/commonissues.rst
@@ -47,7 +47,7 @@ not be an issue for most users. For some applications you might with to turn it
 off::
 
     child = pexpect.spawn ("ssh user@example.com")
-    child.delaybeforesend = 0
+    child.delaybeforesend = None
 
 Truncated output just before child exits
 ----------------------------------------
diff --git a/pexpect/pty_spawn.py b/pexpect/pty_spawn.py
index 299016c..1e9a032 100644
--- a/pexpect/pty_spawn.py
+++ b/pexpect/pty_spawn.py
@@ -144,8 +144,7 @@ class spawn(SpawnBase):
         many users that I decided that the default pexpect behavior should be
         to sleep just before writing to the child application. 1/20th of a
         second (50 ms) seems to be enough to clear up the problem. You can set
-        delaybeforesend to 0 to return to the old behavior. Most Linux machines
-        don't like this to be below 0.03. I don't know why.
+        delaybeforesend to None to return to the old behavior.
 
         Note that spawn is clever about finding commands on your path.
         It uses the same logic that "which" uses to find executables.
@@ -511,7 +510,8 @@ class spawn(SpawnBase):
             >>> bash.sendline('x' * 5000)
         '''
 
-        time.sleep(self.delaybeforesend)
+        if self.delaybeforesend is not None:
+            time.sleep(self.delaybeforesend)
 
         s = self._coerce_send_string(s)
         self._log(s, 'send')
diff --git a/tests/test_delay.py b/tests/test_delay.py
new file mode 100644
index 0000000..8674336
--- /dev/null
+++ b/tests/test_delay.py
@@ -0,0 +1,27 @@
+# -*- coding: utf-8 -*-
+
+from . import PexpectTestCase
+import pexpect
+
+
+class TestCaseDelay(PexpectTestCase.PexpectTestCase):
+    """
+    Tests for various delay attributes.
+    """
+    def test_delaybeforesend(self):
+        """
+        Test various values for delaybeforesend.
+        """
+        p = pexpect.spawn("cat")
+
+        p.delaybeforesend = 1
+        p.sendline("line 1")
+        p.expect("line 1")
+
+        p.delaybeforesend = 0.0
+        p.sendline("line 2")
+        p.expect("line 2")
+
+        p.delaybeforesend = None
+        p.sendline("line 3")
+        p.expect("line 3")