Instead of just resetting the temp dir, let's reset all environment
variables.
Environment variables are a pain for testing. A more reliable solution
would be to refactor all functions that read from the environment to
take the environment as an explicit argument, and then provide a
consistent environment during testing. But that would be a significantly
larger change than this one.
Related to #1105.
In some windows setups, os.TempDir() will return something like
"C:\WINDOWS" if none of the expected environment variables (TMP, TEMP,
USERPROFILE) are set, and then functions that try to create temporary
files or directories will fail since this is not writable.
Several tests in flag_test.go clear the environment and then set a small
number of specific environment variables for the test, triggering the
following error in TestFlagFromFile when I run `go test ./...` on a new
windows machine:
flag_test.go:1667: open C:\WINDOWS\urfave_cli_test851254863: Access is denied.
To work around this, we can check the temp directory before calling
os.Clearenv() and use that directory explcitly in functions that
take the temp directory.
This fixes part of #1105.
Prior to this change, this test was failing for me on a new windows
machine, with mismatching drive letters:
helpers_test.go:20: (C:/Users/Foo Bar/cli/altsrc/flag_test.go:195) Expected C:\path\to\source\hello (type string) - Got D:\path\to\source\hello (type string)
Rather than hard-coding the drive letter in the expected path, we can
expect the filepath.Abs'ed version.
This should fix part of #1105.
Mostyn Bramley-Moore