If checkstyle is configured with custom options that contain "-c" then
the checkstyle config file option is ignored. This PR modifies the
regular expression when creating the checkstyle command to avoid this.
Checkstyle xml configuration is mandatory and not providing one causes
the tool to fail with the following error:
Must specify a config XML file.
Checkstyle itself contains a default configuration as part of its
assests named `/google_checks.xml`. Invoking checkstyle with this config
works even if such file does not exists in the file system:
checkstyle -c /google_checks.xml
This should be the default invocation to allow ALE to use checkstyle
with zero configuration.
Also when a user sets `g:ale_java_checkstyle_config` option, ALE should
use it to invoke checkstyle even such file does not exists in the
filesystem. This is because checkstyle is able to use configuration files
within JAR files defined in the CLASSPATH. The default `/google_checks.xml`
is an example of such configuration available within a JAR resource.
The checkstyle handler is capable of parsing the new and old output
formats. Unfortunately there are some particular output messages that
matched both the new and old regular expressions:
[WARN] whatever:11:7: WhitespaceAround: ''if'' is not followed by whitespace. [WhitespaceAround]
This caused ALE to report extra errors since the message was being
matched twice, once as a warning and another (incorrect) old formatted
error.
This MR fixes this by stopping any parsing using the old format regexp
is any errors of the new format are correcly parsed. There is no reason
to expect checkstyle to output both styles in the same report.
The output format used by older checkstyle versions differs from the one
of new versions. This commit adds a second parsing iteration on the
output lines with a suitable pattern to support both versions in
parallel. Due to the differences in the order of matching groups this is
hard to achieve in a single pass through the output lines.
An appropriate test case is added.
fwy
Horacio Sanson
w0rp
Johannes Wienke
Devon Meunier