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@cpovirk cpovirk released this 02 Feb 19:16
· 38 commits to master since this release

In this release, our assertions on Java 8 types continue to move from the Truth8 class to the main Truth class. This change should not break compatibility for any supported JDK or Android version, even users who test under old versions of Android without API desugaring. Additionally, we will never break binary compatibility, though some users will have to make changes to their source code in order for it to compile against newer versions.

This release is likely to lead to more build failures than 1.3.0 did. However, those failures should be straightforward to fix.

Example build failure error: reference to assertThat is ambiguous
  both method assertThat(@org.checkerframework.checker.nullness.qual.Nullable Path) in Truth8 and method assertThat(@org.checkerframework.checker.nullness.qual.Nullable Path) in Truth match

Simplest upgrade strategy (if you can update all your code atomically in the same commit as the Truth upgrade)

In the same commit:

  1. Upgrade Truth to 1.4.0.
  2. Replace import static; with import static;.
    • If you use Kotlin, replace import with import
  3. Replace import; with import;.
    • again, similarly for Kotlin if needed
  4. Optionally replace remaining references to Truth8 with references to Truth.
    • For example, replace Truth8.assertThat(optional).isPresent() with Truth.assertThat(optional).isPresent().

If you're feeling lucky, you can try this one-liner for the code updates:

git grep -l Truth8 | xargs perl -pi -e 's/import static;/import static;/g; s/import; s/import; s/\bTruth8[.]/Truth./g;'

In most cases, that can be further simplified to:

git grep -l Truth8 | xargs perl -pi -e 's/\bTruth8\b/Truth/g;'

After that process, it is possible that you'll still see build errors from ambiguous usages of assertThat static imports. If so, you can find a workaround in the section about overload ambiguity in the release notes for 1.3.0. Alternatively, you can wait to upgrade until after a future Truth release, which will eliminate the ambiguity by changing the signatures of some Truth.assertThat overloads.

Incremental upgrade strategy

If you have a very large repo or you have other reasons to prefer to upgrade incrementally, you can use the approach that we used inside Google. Roughly, that approach was:

  1. Make the optional changes discussed in the release notes for 1.3.0.
  2. For any remaining calls to Truth8.assertThat, change them to avoid static import.
    • That is, replace assertThat(optional).isPresent() with Truth8.assertThat(optional).isPresent().
  3. Upgrade Truth to 1.4.0.
  4. Optionally replace references to Truth8 with references to Truth (including restoring static imports if desired), as discussed in section about the simple upgrade strategy above.

Optional additional changes

  • If you use assertWithMessage(...).about(intStreams()).that(...), expect.about(optionalLongs()).that(...), or similar, you can remove your call to about. This change will never be necessary; it is just a simplification.
    • This is similar to a previous optional change from 1.3.0, except that 1.3.0 solved this problem for streams and optionals, whereas 1.4.0 solves it for the other Truth8 types.

For help

Please feel welcome to open an issue to report problems or request help.


  • Added the remaining Truth8.assertThat overloads to the main Truth class. (9be8e77, 1f81827)
  • Added more that overloads to make it possible to write type-specific assertions when using the remaining Java 8 types. (7c65fc6)