Dependency checking environment (#124)

* Dependency checking environment

Add an tox environment that does static analysis (via pylint) without
install test-requirements.txt; this ensures that the dependencies
specified in setup.py are enough. Previously, the
tests could pass but the package might not build if a necessary
dependency was specified in the test environment but not in the real
package metadata. Remove requirements.txt, which is redundant with
setup.py.

Also, switch to using grpcio-tools to provide protoc
- It is difficult to debug linuxbrew problems on Travis; it's cleaner just
  to install a Python package.
- Note that grpcio-tools does not install properly for pip versions <8.

Also, fix an import for style
- Directly importing the method is inconsistent with the rest
  of this repo.
- The import causes Sphinx to document the method as though it were
  part of `api_callable`, even though it really belongs to a third-
  party library.

.travis.yml

@@ -1,14 +1,9 @@
 sudo: false
-env:
-  - BREW_HOME=$HOME/.linuxbrew PATH=$BREW_HOME/bin:$PATH
 
 # Protobuf is very expensive to install, so we cache it between builds
 before_install:
   - pip install --upgrade pip
-  - ./install-protobuf3.sh
-cache:
-  directories:
-    - $BREW_HOME
+  - pip --version
 
 language: python
 python:

google/gax/api_callable.py

@@ -33,7 +33,7 @@
 import random
 import time
 
-from future.utils import raise_with_traceback
+from future import utils
 
 from . import (BackoffSettings, BundleOptions, bundling, CallSettings, config,
                PageIterator, ResourceIterator, RetryOptions)
@@ -430,7 +430,7 @@ def inner(*args, **kwargs):
             return a_func(*args, **kwargs)
         # pylint: disable=catching-non-exception
         except tuple(errors) as exception:
-            raise_with_traceback(GaxError('RPC failed', cause=exception))
+            utils.raise_with_traceback(GaxError('RPC failed', cause=exception))
 
     return inner
 

test-requirements.txt

@@ -3,3 +3,11 @@ pytest>=2.8.3
 pytest-cov>=1.8.1
 pytest-timeout>=1.0.0
 unittest2>=1.1.0
+
+# TODO: remove this line when grpcio goes to 1.0.0. This is only necessary
+# because pip (running in Travis CI) will not install the release candidate
+# when it gets pulled in as a dependency of grpcio-tools, below, which causes
+# build failure in Python 3 environments
+grpcio>=1.0.0rc1
+
+grpcio-tools>=1.0.0rc2

tox.ini

@@ -1,20 +1,19 @@
 [tox]
-envlist = py27,py34,py35,pep8,pylint-errors,pylint-full
+envlist = py27,py34,py35,pep8,pylint-errors,pylint-full,pylint-no-test-deps
 
 [tox:travis]
-2.7 = py27,pep8,pylint-full,docs
-3.4 = py34,pep8,pylint-full
-3.5 = py35,pep8,pylint-full
+2.7 = py27,pep8,pylint-full,pylint-no-test-deps,docs
+3.4 = py34,pep8,pylint-full,pylint-no-test-deps
+3.5 = py35,pep8,pylint-full,pylint-no-test-deps
 
 [testenv]
 setenv =
-       PYTHONPATH = {toxinidir}:{toxinidir}/src-gen/test
+       PYTHONPATH = {toxinidir}:{toxinidir}/src-gen
 deps = -r{toxinidir}/test-requirements.txt
-       -r{toxinidir}/requirements.txt
 whitelist_externals = mkdir
                       protoc
 commands = -mkdir src-gen
-           -{env:BREW_HOME}/bin/protoc --python_out=src-gen test/fixture.proto
+           -python -m grpc.tools.protoc -Itest --python_out=src-gen test/fixture.proto
            -py.test --timeout=30 --cov-report html --cov-report=term --cov {toxinidir}/google
 
 [testenv:pep8]
@@ -24,17 +23,19 @@ commands = flake8 --max-complexity=10 google test --ignore=E501 --exclude=src-ge
 [testenv:pylint-errors]
 deps = pylint
        -r{toxinidir}/test-requirements.txt
-       -r{toxinidir}/requirements.txt
 commands = pylint -f colorized -E google test --ignore=src-gen
 
 [testenv:pylint-warnings]
 deps = pylint
 commands = pylint -f colorized -d all -e W -r n google test --ignore=src-gen
 
+[testenv:pylint-no-test-deps]
+deps = pylint
+commands = pylint -f colorized -e E,W,R -d fixme,locally-disabled google --ignore=src-gen
+
 [testenv:pylint-full]
 deps = pylint
        -r{toxinidir}/test-requirements.txt
-       -r{toxinidir}/requirements.txt
 commands = pylint -f colorized -e E,W,R -d fixme,locally-disabled google test --ignore=src-gen
 
 [testenv:devenv]
@@ -43,8 +44,6 @@ envdir = {toxworkdir}/develop
 basepython = python2.7
 usedevelop = True
 deps= -r{toxinidir}/test-requirements.txt
-      -r{toxinidir}/requirements.txt
-
 
 [testenv:docs]
 basepython = python2.7
@@ -56,6 +55,5 @@ commands =
   sphinx-build -W -b html -d docs/_build/doctrees docs docs/_build/html
   sphinx-build -b latex -D language=en -d _build/doctrees docs _build/latex
 deps =
-  -r{toxinidir}/requirements.txt
   Sphinx
   sphinx_rtd_theme