[fix] Issues related to OSInfo.bash_path()

[jgsogo]

Fails when there is no windows_subsytem

Changelog: Bugfix: Fixed OSInfo.bash_path() when there is no windows_subsystem.

[jgsogo]

I need to fix also this test, but I need some advice about it...

conan/conans/test/util/tools_test.py

Line 813 in 860fb81

def run_in_bash_test(self):

It fails when there is no windows_subsystem because of these lines in run_in_windows_bash:

        bash_path = os_info.bash_path()  # <--- Returns None!!!
        bash_path = '"%s"' % bash_path if " " in bash_path else bash_path

We can skip the test if not os_info.detect_windows_subsystem() or run these tests only if cygwin is present...

[memsharded]

What you spotted is indeed a bug in the test, good catch.

The run_in_bash_test() bug, I am not sure, the test seems Mocked, so it shouldn't need a real subsystem to run, what am I missing? How does the test fail in your system?

[jgsogo]

The two lines from function run_in_windows_bash that I copied from the function code:

        bash_path = os_info.bash_path()  # <--- Returns None!!!
        bash_path = '"%s"' % bash_path if " " in bash_path else bash_path

If there is no "bash" in the system, bash_path is None (see comment) and in the next line it is trying to iterate it: if " " in bash_path, so:

======================================================================
ERROR: run_in_bash_test (conans.test.util.tools_test.ToolsTest)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "C:\Javi\dev\conan\conans\test\util\tools_test.py", line 830, in run_in_bash_test
    tools.run_in_windows_bash(conanfile, "a_command.bat", subsystem="cygwin")
  File "C:\Javi\dev\conan\conans\client\tools\win.py", line 481, in run_in_windows_bash
    bash_path = '"%s"' % bash_path if " " in bash_path else bash_path
TypeError: argument of type 'NoneType' is not iterable

To keep the test we need to mock the call to bash_path().

[memsharded]

Yes, I think that mocking OSInfo.bash_path() could be the way to go, specially because in the test, we can see:

   with tools.environment_append({"CONAN_BASH_PATH": "path\\to\\mybash.exe"}):
            tools.run_in_windows_bash(conanfile, "a_command.bat", subsystem="cygwin")
            self.assertIn('path\\to\\mybash.exe --login -c', conanfile._runner.command)

Maybe it is good enough to set CONAN_BASH_PATH, instead of actually mocking.