Assert validity of stream parameters.

recipe_engine/stream.py

Index: recipe_engine/stream.py
diff --git a/recipe_engine/stream.py b/recipe_engine/stream.py
index 831e69b0e9bfab75ca31cbae0cfe30f152bf4f26..194ea3aba1c0f2c24ce86d5566b2a736aca3e47c 100644
--- a/recipe_engine/stream.py
+++ b/recipe_engine/stream.py
@@ -93,6 +93,7 @@ class StreamEngine(object):
 
   def make_step_stream(self, name, **kwargs):
     """Shorthand for creating a step stream from a step configuration dict."""
+    assert '\n' not in name, 'Stream name must not contain a newline.'
     kwargs['name'] = name
     return self.new_step_stream(recipe_api.StepConfig.create(**kwargs))
 
@@ -314,7 +315,7 @@ class StreamEngineInvariants(StreamEngine):
       self._status = 'SUCCESS'
 
     def write_line(self, line):
-      assert '\n' not in line
+      assert '\n' not in line, 'Individual line must not contain a newline.'
       assert self._open
 
     def close(self):
@@ -328,19 +329,22 @@ class StreamEngineInvariants(StreamEngine):
       assert self._open
       assert log_name not in self._logs, 'Log %s already exists in step %s' % (
           log_name, self._step_name)
+      assert '\n' not in log_name, 'Log name must not contain a newline.'
       ret = self._engine.LogStream(self, log_name)
       self._logs[log_name] = ret
       return ret
 
     def add_step_text(self, text):
-      pass
+      assert '\n' not in text, 'Step text must not contain a newline.'
 
     def add_step_summary_text(self, text):
-      pass
+      assert '\n' not in text, 'Step summary text must not contain a newline.'
 
     def add_step_link(self, name, url):
       assert isinstance(name, basestring), 'Link name %s is not a string' % name
-      assert isinstance(url, basestring), 'Link url %s is not a string' % url
+      assert '\n' not in name, 'Link name must not contain a newline.'
+      assert isinstance(url, basestring), 'Link URL %s is not a string' % url
+      assert '\n' not in url, 'Link URL must not contain a newline.'

[iannucci, 2017/04/05 02:40:23]

Since these values are user-controlled (i.e. they vary at runtime), it would be
better not to use `assert` for them (since -O removes asserts in cpython:
`python -O -c 'assert False'` exits 0).

Would you mind switching the asserts in this file to a function (maybe
"check()"?) that raises ValueError instead?

[dnj, 2017/04/05 15:08:07]

Done.

 
     def set_step_status(self, status):
       assert status in ('SUCCESS', 'WARNING', 'FAILURE', 'EXCEPTION')
@@ -351,11 +355,13 @@ class StreamEngineInvariants(StreamEngine):
       self._status = status
 
     def set_build_property(self, key, value):
-      pass
+      assert '\n' not in key, 'Property key must not contain a newline.'
+      assert '\n' not in value, 'Property value must not contain a newline.'
+      json.loads(value) # value must be a valud JSON object.

[iannucci, 2017/04/05 02:40:23]

nit: valud

[dnj, 2017/04/05 15:08:07]

Done.

 
     def trigger(self, spec):
-      assert '\n' not in spec # Spec must fit on one line.
-      json.loads(spec) # Spec must be a valid json object.
+      assert '\n' not in spec, 'Spec must not contain a newline.'
+      json.loads(spec) # Spec must be a valid JSON object.
 
   class LogStream(StreamEngine.Stream):
     def __init__(self, step_stream, log_name):
@@ -364,7 +370,7 @@ class StreamEngineInvariants(StreamEngine):
       self._open = True
 
     def write_line(self, line):
-      assert '\n' not in line
+      assert '\n' not in line, 'Inividual line must not contain a newline.'
       assert self._step_stream._open
       assert self._open