https://github.com/willlillis/lspresso-shot
A concentrated dose of LSP testing power!
https://github.com/willlillis/lspresso-shot
lsp testing
Last synced: 9 months ago
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A concentrated dose of LSP testing power!
- Host: GitHub
- URL: https://github.com/willlillis/lspresso-shot
- Owner: WillLillis
- License: mit
- Created: 2025-01-14T06:01:14.000Z (over 1 year ago)
- Default Branch: master
- Last Pushed: 2025-06-24T03:29:37.000Z (about 1 year ago)
- Last Synced: 2025-10-04T05:55:33.710Z (9 months ago)
- Topics: lsp, testing
- Language: Rust
- Homepage:
- Size: 532 KB
- Stars: 2
- Watchers: 1
- Forks: 1
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# LSPresso-Shot
A concentrated dose of LSP testing power!
## Goal
Provide an easy way to perform integration tests on language servers implemented in Rust.
## Usage
First, add lspresso-shot as a dependency to your Rust project:
```shell
cargo add --dev lspresso-shot
```
Write a test:
```rust
#[test]
fn it_does_the_hover_thing() {
let hover_test_case = TestCase::new(
"Path to server",
TestFile::new("Source file name", "Contents")
)
.other_file( // Optional
TestFile::new("Other file name", "Other contents")
);
let cursor_pos = Position::new(1, 2);
lspresso_shot!(test_hover(
hover_test_case,
cursor_pos,
Some(&Hover {
range: Some(Range {
start: lsp_types::Position {
line: 1,
character: 2,
},
end: lsp_types::Position {
line: 3,
character: 4,
},
}),
contents: lsp_types::HoverContents::Markup(MarkupContent {
kind: lsp_types::MarkupKind::Markdown,
value: "Hover window contents here".to_string(),
})
})
));
}
```
Or a benchmark:
```rust
fn blazingly_fast() {
let references_test_case = TestCase::new(
"Path to server",
TestFile::new("Source file name", "Contents")
);
let cursor_pos = Position::new(1, 2);
let include_declaration = true;
let measurements: Vec = benchmark_references(
&test_case,
BenchmarkConfig::default(),
cursor_pos,
include_declaration,
);
}
```
That's it!
## Dependencies:
Neovim must be available on your `$PATH`. See the project's [documentation][nvim-install-docs]
for installation instructions. Versions at or later than [`517ecb8`][nvim-min-commit]
are necessary.
## Examples:
- The library's test corpus uses [rust-analyzer][rust-analyzer]. See [`test-suite/src/*`][repo-tests]
for examples of how to use the library.
- TODO: Add asm-lsp/other LSPs here once it's being used.
## Gotchas/Known Issues
- If your server undergoes some sort of indexing process at startup before it's ready
to service a given request, you need to account for this by specifying `ServerStartType::Progress(NonZeroU32, String)`
to the test case. The `NonZeroU32` specifies *which* `end` message to issue the request
after (in case there are multiple). The `String` provides the relevant [progress token][progress-token].
- **String comparison of results**: Many LSP client implementations do some post processing
of responses returned by a given language server before displaying it to the user. Your expected
response may need to be minimally altered from what you see in your editor in order for tests
to pass.
- **Uri fields**: If a response contains a Uri field with an absolute path, this field
will be sanitizd to a relative path up to the test case's root directory. Your test case's
expected results may need to be adjusted to reflect this.
- **Variance in LSP client implementation**: The [LSP Spec][lsp-spec] is somewhat loosely defined,
leaving plenty of room for client implementations to behave differently from one another. This
project utilizes [neovim][nvim-repo]'s, meaning that unexpected behavior may occur when your server
is used with other editors' clients.
- **Ambiguous Deserialization of Response Types**: Several response types specified in the
[LSP Spec][lsp-spec] are ambiguously deserialized to multiple types from their JSON representations.
Because the LSP specification is defined over JSON RPC, this means that the value received by the
LSP client may not match the value sent by your server. Any request affected by ambiguity will treat
such values as equal in using the default comparison logic. Error messages may still display incorrect
or misleading types, however.
## Contributing
- In addition to [neovim][nvim-repo], working on this project also requires having having
[rust-analyzer][rust-analyzer] rust-analyzer 1.87.0 (17067e9 2025-05-09) on your `$PATH`, as it is used in the project's test suite.
[lsp-spec]: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/
[progress-token]: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#progress
[nvim-repo]: https://github.com/neovim/neovim
[nvim-install-docs]: https://github.com/neovim/neovim#install-from-source
[nvim-min-commit]: https://github.com/neovim/neovim/commit/517ecb85f58ed6ac8b4d5443931612e75e7c7dc2
[rust-analyzer]: https://github.com/rust-lang/rust-analyzer
[repo-tests]: https://github.com/WillLillis/lspresso-shot/tree/master/test-suite/src