This folder contains unit tests of the CPS IR. These tests run the compiler with the cps IR and check for the output of a specific function (typically main).
To make our lives easier, most files here are autogenerated. You should never have to edit a file under expected/ or any file with an AUTOGENERATED header (including the _test.dart files).
See instructions below to add or update tests.
Every test has 3 files: an input file, a test runner file, and an expectation file. The last two are auto-generated. Here is how:
add a file under input/ with a unique name, such as foo_bar.dart. Do not include _test in the name of this file, otherwise the test framework will think this test needs to be run directly in the vm and in a browser, that's not our goal.
generate the corresponding test file, by running the up_to_date_test.dart passing update as an argument:
dart tests/compiler/dart2js/cps_ir/up_to_date_test.dart update
This will generate a file foo_bar_test.dart on this folder.
update as an argument:dart --package-root=out/ReleaseX64/packages tests/compiler/dart2js/cps_ir/foo_bar_test.dart update
This will generate a file expected/foo_bar.js with the expected output.
By default, the test expectations will be generated to contain just the body of the main function. If you wish to check for a different element, include a comment at the top of the input test like this:
// Method to test: function(foo)
The trailing text should match the string representation of a compiler element.
Note: this format will likely change in the future. We would like to have a canonical way to refer to elements that is independent of the internal compiler implementation, we also want a way to specify more than just one element, and a way to specify that an element has been tree-shaken.
To update the expectations of a test, simply regenerate it by running the test file with update as an argument:
dart --package-root=out/ReleaseX64/packages tests/compiler/dart2js/cps_ir/foo_bar_test.dart update
This will override the file expected/foo_bar.js file with the new output.
If a test fails because the expectations are out of date, you'll see this suggestion in the failure message too.
For convenience, we also provide a script to update all expectations at once.
dart --package-root=out/ReleaseX64/packages tests/compiler/dart2js/cps_ir/update_all.dart
It is equivalent to update each test individually. This script can be handy when making cross-cutting changes that affect the output of most tests.