This subfolder builds a private command line binary used by the plugin to power a few functionalities such as jump to definition, hover and autocomplete.

The binary reads the .cmt and .cmti files and analyses them.

For installation & build instructions, see the main CONTRIBUTING.md.

See main CONTRIBUTING.md's repo structure. Additionally, examples/ is a convenience debugging repo. Check out test.sh (invoked through make test) to see the snapshots testing workflow stored in tests/.

dune exec -- rescript-editor-analysis --help

Add verbose logging via:

dune exec -- rescript-editor-analysis debug-dump verbose test

This project is based on a fork of Reason Language Server.

• Ensure the compiler is built (make build in the repository root).
• Ensure the library is built (make lib in the repository root).

Run make test in tests/analysis_tests/tests.

The tests in the tests/analysis_tests/tests folder are based on the dune exec -- rescript-editor-analysis test command. This special subcommand processes a file and executes specific editor analysis functionality based on special syntax found in code comments.

Consider the following code:

let a = 5
// a.
//   ^com

After building the ReScript project (⚠️ this is a requirement), you can execute dune exec -- rescript-editor-analysis test Sample.res, and completion will be performed for the cursor position indicated by ^. The com directive requests completion. To see other commands, check out the pattern match in the test function in Commands.ml.

Here’s how it works: once a command is found in a comment, a copy of the source file is created inside a temporary directory, where the line above ^com is uncommented. The corresponding analysis functionality is then processed, typically with ~debug:true. With debug enabled, code paths like

if Debug.verbose () then
      print_endline "[complete_typed_value]--> Tfunction #other";

will print to stdout. This is helpful for observing what happens during the analysis.

When you run make test (from the tests/analysis_tests folder), dune exec -- rescript-editor-analysis test <file> will be executed for each *.res file in analysis/tests/src. The stdout will be compared to the corresponding analysis/tests/src/expected file. If git diff indicates changes, make test will fail, as these differences might be unintentional.

To use a local version of rescript-editor-analysis, the targeted project needs to be compiled with the local compiler.

Install your local ReScript with npm i /path/to/your-local-rescript-repo. Reinstall the dependencies and run npx rescript in your project. This ensures the project is compiled with the same compiler version that the rescript-editor-analysis will process.

It is possible to debug analysis via ocamlearlybird.

1. Install opam install earlybird.
2. Install the earlybird extension.
3. Create a launch configuration (.vscode/launch.json):

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Debug analysis",
            "type": "ocaml.earlybird",
            "request": "launch",
            "program": "${workspaceFolder}/_build/default/analysis/bin/main.bc",
            "stopOnEntry": true,
            "cwd": "/projects/your-project",
            "env": {
                "CAML_LD_LIBRARY_PATH": "${workspaceFolder}/_build/default/compiler/ext"
            },
            "arguments": [
                "test",
                "src/Main.res"
            ]
        }
    ]
}

The CAML_LD_LIBRARY_PATH environment variable is required to tell OCaml where dllext_stubs.so can be loaded from.