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spin out of #9215

@scala-jenkins scala-jenkins added this to the 2.12.13 milestone Sep 20, 2020
@lrytz lrytz merged commit 19f0d97 into scala:2.12.x Sep 21, 2020
@SethTisue SethTisue added library:collections PRs involving changes to the standard collection library performance the need for speed. usually compiler performance, sometimes runtime performance. labels Oct 1, 2020
finaglehelper pushed a commit to twitter/finatra that referenced this pull request Mar 11, 2021
Problem
=======

Upgrade source to https://github.com/scala/scala/releases/tag/v2.12.13 from https://github.com/scala/scala/releases/tag/v2.12.12. This upgrade includes a highlighted feature of configurable warnings and errors (https://www.scala-lang.org/2021/01/12/configuring-and-suppressing-warnings.html / scala/scala#9248).

Other noticable changes our code based will experience

* Exhaustivity warnings for patterns involving tuples
* Better type checking for `CharSequence` arguments scala/scala#9292
* Simplified Reporters scala/scala#8338
* Promotion of `-deprecation` to `-Xlint:deprecation` scala/scala#7714
* Improves performance of building `immutable.{TreeMap,TreeSet}` by using mutation within the builder scala/scala#8794

Full list of changes can be found at https://github.com/scala/scala/pulls?q=is%3Amerged+milestone%3A2.12.13+

Solution
========

* Bump `BUILD` file `SCALA_REV` && `SCALAC_REV_FOR_DEPS`.
* Depdnencies which are not built for scala 2.12.13 needed to be bumped `SEMANTICDB_PLUGIN_REV` && `SEMANTICDB_REV` && `SCALAFIX_REV`.
* Include `-S-Xlint:-deprecation` to `pants.ini` preventing build failures on deprecated annotations (existing behavior)
* Bump `cache_key_gen_version` in `pants.ini` for newly built artifacts on different scala version.
* Removed scalafix plugin (`scalac-profiling`) which is not built for 2.12.13. `scalac-profiling` code looks abandoned by ~3 years.
* Updated all failing tests that could have depended or expected ordered sequences when the sequence was generated from non ordered collections.

Notes
=====

It seems a few tests and golden files in source have depended or tested against a stable sort order when sorted order is not guaranteed. This has been seen in a few places such as output json objects (map key fields), code that uses `groupBy` for rekeying results to the user and transforming into sequences, strings built from sequences or maps that are not guaranteed to be ordered.

The following PR are related to this change in expectations

scala/scala#8794
scala/scala#8948
scala/scala#9218
scala/scala#9376
scala/scala#9091
scala/scala#9216

We took the liberty updating tests with what the current map order would be or updating the test in a way that wouldn't depend on order. Since we may not fully understand all the context of the tests we are hoping this either signals to the owners that there might be some issue with assumed order or signal that upgrading might break implementations due to bug in scala 2.12.13. {D611202} will improve the files changed for workflow builder outside of this change.

Please feel to reach out directly and discuss the changes here or bring up issues with this upgrade. Slack [[https://app.slack.com/client/T86S8GHEG/C01NZAFRLFK|#scala-upgrade-2-12-13]]

JIRA Issues: SCALA-25

Differential Revision: https://phabricator.twitter.biz/D607826
hamzaremmal pushed a commit to hamzaremmal/scala3 that referenced this pull request May 2, 2025
…dRight

ListMap is reverse oriented, so use that for foldRight
hamzaremmal pushed a commit to scala/scala3 that referenced this pull request May 7, 2025
…dRight

ListMap is reverse oriented, so use that for foldRight
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4 participants