Add support to update root gradle.properties

[asodja]

This fixes: #28.

Basic idea:

• everyuseLatestVersions task writes variables to build/useLatestVersions/version-variables.json
• we have one "aggregation" task internalRootAggregate that at the end reads all version-variables.json, merges them if possible (there is check that versions match) and writes to gradle.properties
• at the end internalRootAggregate also deletes all version-variables.json files
• all useLatestVersions tasks are finalized by internalRootAggregate task and internalRootAggregate task must run after all useLatestVersions tasks

By default this behavior is disabled, but can be enabled with --updateRootProperties or as:

useLatestVersions {
   updateRootProperties=true  
}

Note: when updateRootProperties=false, subprojects won't make version-variables.json file, but internalRootAggregate task will be run anyway, it just won't be able to read variables of subprojects.

I also included one small change, now variables that are defined multiple times in *.gradle file are also matched (change in Common.getVariablesFromMatches). Previously if you had two same version variables in *.gradle file it was not updated (also no problem was printed).

[patrikerdes]

Hi! Thank you very much for this PR!
The integration tests were not passing on the master branch, I have fixed that now. So if you could rebase on master and push your branch, travis-ci will run your branch and we can see that it is passing the tests.
(Travis builds of PRs: https://travis-ci.org/github/patrikerdes/gradle-use-latest-versions-plugin/pull_requests)

Also, I couldn't see any new tests being added in this PR. I would be really grateful if you could also add tests that verify that the new functionality is working.

[asodja]

Hej @patrikerdes,

sure, I can do that. Oh I see, I updated com.github.ben-manes.versions version in tests due to plugin test failure and this version does not support Gradle < 5.0, sorry for that.

Regarding tests, I can also write some. So probably I should add it to VariableUpdatesFunctionalTest right? Is there any helper code for multiproject tests?

[patrikerdes]

VariableUpdatesFunctionalTest sounds good to me.
I'm not aware of any such helper code, I think you will have to just create a number of different files in the correct folders. testProjectDir is the base directory where you can create files and folders using testProjectDir.newFolder or testProjectDir.newFile, you can find examples of those being used in other tests where more than one file is needed for the test.

[asodja]

Ok, I think I can see how I can handle tests. :)

I will rebase and also add tests, probably not today but in next few days.

Also thanks for a plugin! It comes really handy.

[asodja]

I added tests. I also had to do a workaround for some other tests since Versions plugin from 0.28 supports only Gradle >= 5.0. Mostly tests for useLatestVersionsCheck failed. Simple workaround was to run problematic tests with blacklisted Versions plugin. Maybe on a long run it would be better to just run tests with Gradle >= 5.0.

I also added a few lines in README.md how to apply plugin in case of Multi-projects build.

[patrikerdes]

I upgraded the gradle wrapper to 6.4.1 as part of fixing the broken tests, so the workaround you did for the failing tests should no longer be necessary. (I checked and you have that commit in your branch now after you rebased.)
Could you revert the change to use $CurrentVersions.SUPPORTED_VERSIONS_PLUGIN in tests, and go back to using $CurrentVersions.VERSIONS again?

[asodja]

My bad, added version change before rebase.

Anyway fixed now. Also diff is smaller and easier to review now.

[patrikerdes]

LGTM

[patrikerdes]

Now available in 0.2.14