Testing in DottyEdit this page on GitHub
Running all tests in Dotty is as simple as:
$ sbt test
There are currently several forms of tests in Dotty. These can be split into two categories:
These tests can be found in
<sub-project>/test and are used to check
functionality of specific parts of the codebase in isolation e.g: parsing,
scanning and message errors.
To run all tests in e.g., for the compiler test-suite you can write:
$ sbt > dotty-compiler/test
To run a single test class you use
testOnly and the fully qualified class name.
> testOnly dotty.tools.dotc.transform.TreeTransformerTest
The test command follows a regular expression-based syntax
testOnly * -- *.
The right-hand side picks a range of names for methods and the left-hand side picks a range of class names and their
Consequently, you can restrict the aforementioned executed test to a subset of methods by appending
The example below picks up all methods with the name
> testOnly dotty.tools.dotc.transform.TreeTransformerTest -- *canOverwrite
Additionally, you can run all tests named
method_name, in any class, without providing a class name:
> testOnly -- *canOverwrite
You can also run all paths of classes of a certain name:
> testOnly *.TreeTransformerTest
These tests are Scala source files expected to compile with Dotty (pos tests), along with their expected output (run tests) or errors (neg tests).
All of these tests are contained in the
./tests/* directories and can be run with the
testCompilation command. Tests in folders named
with-compiler are an exception, see next section.
Currently to run these tests you need to invoke from sbt:
$ sbt > testCompilation
(which is effectively the same with
It is also possible to run tests filtered, again from sbt:
$ sbt > testCompilation companions
This will run both the test
./tests/neg/companions.scala since both of these match the given string.
This also means that you could run
testCompilation with no arguments to run all integration tests.
When complex checkfiles must be updated,
testCompilation can run in a mode where it overrides the checkfiles with the test outputs.
$ sbt > testCompilation --update-checkfiles
testCompilation on a bootstrapped Dotty compiler, use
dotty-compiler-bootstrapped/testCompilation (with the same syntax as above).
Some tests can only be run in bootstrapped compilers; that includes all tests
with-compiler in their name.
testCompilation has a additional mode to run tests that compile code from a
.tasty file, decompile a
.tasty file and recompile the decompiled tasty.
Modify blacklist and whitelists in
compiler/test/dotc to enable or disable tests from
$ sbt > testCompilation --from-tasty
This mode can be combined with
--update-checkfiles to update the
.decompiled files or can be run under
dotty-compiler-bootstrapped/testCompilation to test on a bootstrapped Dotty compiler.