swc-installation-test-2.py: Add CommandDependency.paths fallbacks

The old CommandDependency implementation assumed that commands would
exist in one of the directories listed in PATH.  This assumption is,
unfortunately, often not satisfied on MS Windows or OS X.  In order to
work around this problem, you can now store a list of fallback paths
that will be tried if there is an error extracting the version stream
from the bare CommandDependency.command.

I've added fallback paths for Notepad++, Firefox, and Google Chrome,
as reported by Ethan White for Windows 7.

setup/README.md

@@ -61,8 +61,8 @@ Before your boot camp, you should go through
 `swc-installation-test-2.py` and comment any dependencies you don't
 need out of the `CHECKS` list.  You might also want to skim through
 the minimum version numbers listed where particular dependencies are
-defined (e.g. `('git', 'Git', (1, 7, 0))`).  For the most part, fairly
-conservative values have been selected, so students with modern
+defined (e.g. `('git', 'Git', (1, 7, 0), None)`).  For the most part,
+fairly conservative values have been selected, so students with modern
 machines should be fine.  If your boot camp has stricter version
 requirements, feel free to bump them accordingly.
 

setup/swc-installation-test-2.py

@@ -394,12 +394,14 @@ def _get_parsed_version(self):
 class CommandDependency (Dependency):
     exe_extension = _distutils_ccompiler.new_compiler().exe_extension
 
-    def __init__(self, command, version_options=('--version',), stdin=None,
-                 version_regexp=None, version_stream='stdout', **kwargs):
+    def __init__(self, command, paths=None, version_options=('--version',),
+                 stdin=None, version_regexp=None, version_stream='stdout',
+                 **kwargs):
         if 'name' not in kwargs:
             kwargs['name'] = command
         super(CommandDependency, self).__init__(**kwargs)
         self.command = command
+        self.paths = paths
         self.version_options = version_options
         self.stdin = None
         if not version_regexp:
@@ -408,14 +410,16 @@ def __init__(self, command, version_options=('--version',), stdin=None,
         self.version_regexp = version_regexp
         self.version_stream = version_stream
 
-    def _get_version_stream(self, stdin=None, expect=(0,)):
+    def _get_command_version_stream(self, command=None, stdin=None,
+                                    expect=(0,)):
+        if command is None:
+            command = self.command + (self.exe_extension or '')
         if not stdin:
             stdin = self.stdin
         if stdin:
             popen_stdin = _subprocess.PIPE
         else:
             popen_stdin = None
-        command = self.command + (self.exe_extension or '')
         try:
             p = _subprocess.Popen(
                 [command] + list(self.version_options), stdin=popen_stdin,
@@ -450,6 +454,27 @@ def _get_version_stream(self, stdin=None, expect=(0,)):
                 return string
         raise NotImplementedError(self.version_stream)
 
+    def _get_version_stream(self, **kwargs):
+        try:
+            return self._get_command_version_stream(**kwargs)
+        except DependencyError as e:
+            if self.paths:
+                or_errors = [e]
+                for path in self.paths:
+                    try:
+                        return self._get_command_version_stream(
+                            command=path, **kwargs)
+                    except DependencyError as e:
+                        print('a')
+                        or_errors.append(e)
+                raise DependencyError(
+                    checker=self,
+                    message='errors finding {0} version'.format(
+                        self.full_name()),
+                    causes=or_errors)
+            else:
+                raise
+
     def _get_version(self):
         version_stream = self._get_version_stream()
         match = self.version_regexp.search(version_stream)
@@ -461,39 +486,50 @@ def _get_version(self):
         return match.group(1)
 
 
-for command,long_name,minimum_version in [
-        ('sh', 'Bourne Shell', None),
-        ('ash', 'Almquist Shell', None),
-        ('bash', 'Bourne Again Shell', None),
-        ('csh', 'C Shell', None),
-        ('ksh', 'KornShell', None),
-        ('dash', 'Debian Almquist Shell', None),
-        ('tcsh', 'TENEX C Shell', None),
-        ('zsh', 'Z Shell', None),
-        ('git', 'Git', (1, 7, 0)),
-        ('hg', 'Mercurial', (2, 0, 0)),
-        ('EasyMercurial', None, (1, 3)),
-        ('pip', None, None),
-        ('sqlite3', 'SQLite 3', None),
-        ('nosetests', 'Nose', (1, 0, 0)),
-        ('ipython', 'IPython script', (0, 13)),
-        ('emacs', 'Emacs', None),
-        ('xemacs', 'XEmacs', None),
-        ('vim', 'Vim', None),
-        ('vi', None, None),
-        ('nano', 'Nano', None),
-        ('gedit', None, None),
-        ('kate', 'Kate', None),
-        ('notepad++', 'Notepad++', None),
-        ('firefox', 'Firefox', None),
-        ('google-chrome', 'Google Chrome', None),
-        ('chromium', 'Chromium', None),
+for command,long_name,minimum_version,paths in [
+        ('sh', 'Bourne Shell', None, None),
+        ('ash', 'Almquist Shell', None, None),
+        ('bash', 'Bourne Again Shell', None, None),
+        ('csh', 'C Shell', None, None),
+        ('ksh', 'KornShell', None, None),
+        ('dash', 'Debian Almquist Shell', None, None),
+        ('tcsh', 'TENEX C Shell', None, None),
+        ('zsh', 'Z Shell', None, None),
+        ('git', 'Git', (1, 7, 0), None),
+        ('hg', 'Mercurial', (2, 0, 0), None),
+        ('EasyMercurial', None, (1, 3), None),
+        ('pip', None, None, None),
+        ('sqlite3', 'SQLite 3', None, None),
+        ('nosetests', 'Nose', (1, 0, 0), None),
+        ('ipython', 'IPython script', (0, 13), None),
+        ('emacs', 'Emacs', None, None),
+        ('xemacs', 'XEmacs', None, None),
+        ('vim', 'Vim', None, None),
+        ('vi', None, None, None),
+        ('nano', 'Nano', None, None),
+        ('gedit', None, None, None),
+        ('kate', 'Kate', None, None),
+        ('notepad++', 'Notepad++', None, [
+            _os.path.join(
+                _ROOT_PATH, 'Program Files', 'Notepad++', 'notepad++.exe'),
+            ]),
+        ('firefox', 'Firefox', None, [
+            _os.path.join(
+                _ROOT_PATH, 'Program Files', 'Mozilla Firefox', 'firefox.exe'),
+            ]),
+        ('google-chrome', 'Google Chrome', None, [
+            _os.path.join(
+                _ROOT_PATH, 'Program Files', 'Google', 'Chrome', 'Application',
+                'chrome.exe'),
+            ]),
+        ('chromium', 'Chromium', None, None),
         ]:
     if not long_name:
         long_name = command
     CHECKER[command] = CommandDependency(
-        command=command, long_name=long_name, minimum_version=minimum_version)
-del command, long_name, minimum_version  # cleanup namespace
+        command=command, paths=paths, long_name=long_name,
+        minimum_version=minimum_version)
+del command, long_name, minimum_version, paths  # cleanup namespace
 
 
 class MakeDependency (CommandDependency):
@@ -561,9 +597,8 @@ class PathCommandDependency (CommandDependency):
     installed version, etc., take a list of paths, and succeed if any
     of them exists.
     """
-    def __init__(self, paths, **kwargs):
-        super(PathCommandDependency, self).__init__(self, **kwargs)
-        self.paths = paths
+    def _get_command_version_stream(self, *args, **kwargs):
+        raise NotImplementedError()
 
     def _get_version_stream(self, *args, **kwargs):
         raise NotImplementedError()
@@ -599,7 +634,7 @@ def _get_version(self):
     if not long_name:
         long_name = name
     CHECKER[name] = PathCommandDependency(
-        paths=paths, name=name, long_name=long_name)
+        command=None, paths=paths, name=name, long_name=long_name)
 del paths, name, long_name  # cleanup namespace