haskell-language-server/test/README.md
fendor 168976d6f5
Cleanup func-test suite (#3828)
* Cleanup func-test suite

This test-suite is vastly legacy from Haskell IDE Engine.
It was originally written before we had a plugin-based architecture
where each plugin tests its feature in isolation.
Over time, this test-suite bitrotted, where a lot of testcases were
either redundant or out-of-date and consequentially disabled.

We clean up the test-suite, delete old tests and remove unused testdata.

* Remove unused config change

* Move qualified import tests to hls-refactor-plugin

* Add README for `func-test`

Provides guidance when to add a test to `func-test` and some historical
context.

* Add fendor as CODEOWNER for `func-test` and `hls-test-utils`

---------

Co-authored-by: Michael Peyton Jones <me@michaelpj.com>
2023-10-09 13:04:34 +00:00

2.0 KiB

The func-test test suite.

This is the integration test suite for cross-plugin and cross-package features.

Add integration tests to func-test only if they satisfy one or more of the following conditions:

  • It tests the interaction between more than one plugin.
    • For example, plugin A provides a Diagnostic that plugin B requires to provide a CodeAction.
    • However, it is also valid, and often preferable, to depend on the required plugin directly in plugin B's test suite.
  • It tests HLS specific LSP code.
    • For example, we test that config changes are appropriately propagated.
      • Note, this is slightly debatable, since the test could also be part of ghcide.
    • Non HLS specific LSP code may exist in HLS temporarily, but any LSP extensions should be upstreamed to lsp.
  • It tests features of the haskell-language-server-wrapper executable.
    • For example, argument parsing.
  • It tests features of the haskell-language-server executable.
    • For example, argument parsing.
  • It tests features provided by hls-plugin-api that require an integration test (i.e. a unit test doesn't suffice).
    • Example: Testing the Logger setup.

If you think that a test that currently lives in func-test does not meet the conditions above, open a ticket for discussion or try to move the test to a better location.

Note: func-test is a historical test suite. It was originally written for Haskell IDE Engine, which was merged with the ghcide project. The integration test-suite func-test (back then unit-test existed as well) was used to test all kinds of features provided by Haskell IDE Engine (HIE). When ghcide and HIE merged together, the integration test suite was vastly copied. HLS moved to a plugin-based architecture, which mainly entails that plugin tests are isolated in the respective plugin's test suite. Over time, func-test started to bit rot and wasn't maintained properly any more, since all new tests were added to the plugin or ghcide test suites.