### What changes were proposed in this pull request?
Update the scalafmt plugin to 1.0.3 and use its new onlyChangedFiles feature rather than --diff
### Why are the changes needed?
Older versions of the plugin either didn't work with scala 2.13, or got rid of the --diff argument and didn't allow for formatting only changed files
### Does this PR introduce any user-facing change?
The /dev/scalafmt script no longer passes through arbitrary args, instead using the arg to select scala version. The issue here is the plugin name literally contains the scala version, and doesn't appear to have a shorter way to refer to it. If srowen or someone else with better maven-fu has an idea I'm all ears.
### How was this patch tested?
Manually, e.g. edited a file and ran
dev/scalafmt
or
dev/scalafmt 2.13
Closes#27279 from koeninger/SPARK-30570.
Authored-by: cody koeninger <cody@koeninger.org>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
### What changes were proposed in this pull request?
Move scalafmt to Scala 2.12 profile; bump to 0.12.
### Why are the changes needed?
To facilitate a future Scala 2.13 build.
### Does this PR introduce any user-facing change?
None.
### How was this patch tested?
This isn't covered by tests, it's a convenience for contributors.
Closes#26655 from srowen/SPARK-29293.
Authored-by: Sean Owen <sean.owen@databricks.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
## What changes were proposed in this pull request?
Add a maven plugin and wrapper script to use scalafmt to format files that differ from git master.
Intention is for contributors to be able to use this to automate fixing code style, not to include it in build pipeline yet.
If this PR is accepted, I'd make a different PR to update the code style section of https://spark.apache.org/contributing.html to mention the script
## How was this patch tested?
Manually tested by modifying a few files and running ./dev/scalafmt then checking that ./dev/scalastyle still passed.
Closes#23148 from koeninger/scalafmt.
Authored-by: cody koeninger <cody@koeninger.org>
Signed-off-by: Sean Owen <sean.owen@databricks.com>
