add setup tests

.travis.yml

@@ -81,17 +81,21 @@ install:
     - python${PYTHON} --version
     - apt-cache search python3-pyqt
     - apt-cache search python3-pyside
-
+    
 
 before_script:
     # We need to create a (fake) display on Travis, let's use a funny resolution
     - export DISPLAY=:99.0
     - /sbin/start-stop-daemon --start --quiet --pidfile /tmp/custom_xvfb_99.pid --make-pidfile --background --exec /usr/bin/Xvfb -- :99 -screen 0 1400x900x24 -ac +extension GLX +render
+    
+    # Make sure everyone uses the correct python
+    - mkdir ~/bin && ln -s `which python${PYTHON}` ~/bin
+    - export PATH=~/bin:$PATH
 
 
 script:
     # Run unit tests
-    - python${PYTHON} setup.py test
+    - python setup.py test
     
     # check line endings
     - if [ "${TEST}" == "extra" ]; then
@@ -104,7 +108,13 @@ script:
 
     # Check for style issues
     - if [ "${TEST}" == "extra" ]; then
-        python${PYTHON} setup.py style;
+        python setup.py style;
       fi;
     
+    # Check install works
+    - CWD=`pwd`
+    - python setup.py install && cd .. && echo "import pyqtgraph.examples" | python
+    
+    # Check double-install fails
+    - cd pyqtgraph && python setup.py install && if [ $? == 0 ]; then false; fi;
 

setup.py

@@ -93,11 +93,25 @@ class Build(distutils.command.build.build):
             sys.excepthook(*sys.exc_info())
         return ret
         
+import distutils.command.install
 
+class Install(distutils.command.install.install):
+    """
+    * Check for previously-installed version before installing
+    """
+    def run(self):
+        name = self.config_vars['dist_name']
+        if name in os.listdir(self.install_libbase):
+            raise Exception("It appears another version of %s is already "
+                            "installed at %s; remove this before installing." 
+                            % (name, self.install_libbase))
+        print("Installing to %s" % self.install_libbase)
+        return distutils.command.install.install.run(self)
         
 setup(
     version=version,
     cmdclass={'build': Build, 
+              'install': Install,
               'deb': helpers.DebCommand, 
               'test': helpers.TestCommand,
               'debug': helpers.DebugCommand,