updated: elixir language server, replaced with expert (#783)

Author: norbu09

.github/workflows/pytest.yml

@@ -90,8 +90,8 @@ jobs:
         if: runner.os != 'Windows'
         uses: erlef/setup-beam@v1
         with:
-          elixir-version: "1.18.4"
-          otp-version: "26.1"
+          elixir-version: "1.19.3"
+          otp-version: "28"
 #      Erlang currently not tested in CI, random hangings on macos, always hangs on ubuntu
 #      In local tests, erlang seems to work though
 #      - name: Install Erlang Language Server

docs/01-about/020_programming-languages.md

@@ -20,7 +20,7 @@ With Serena, we provide direct, out-of-the-box support for:
 * **Clojure**
 * **Dart**
 * **Elixir**  
-  (requires installation of NextLS and Elixir; Windows not supported)
+  (requires Elixir installation; Expert language server is downloaded automatically)
 * **Elm**  
   (requires Elm compiler)
 * **Erlang**  

pyproject.toml

@@ -301,6 +301,7 @@ markers = [
   "fortran: language server running for Fortran",
   "haskell: Haskell language server tests",
   "yaml: language server running for YAML",
+  "slow: tests that require additional Expert instances and have long startup times (~60-90s each)",
 ]
 
 [tool.codespell]

src/solidlsp/language_servers/elixir_tools/README.md

@@ -1,18 +1,6 @@
 # Elixir Language Server Integration
 
-This directory contains the integration for Elixir language support using [Next LS](https://github.com/elixir-tools/next-ls) from the elixir-tools project.
-
-> **⚠️ Windows Not Supported**: Next LS does not provide Windows binaries, so Elixir language server integration is only available on Linux and macOS.
-
-## Known Issues
-
-### Next LS v0.23.3 Timeout Enumeration Bug
-There is a known intermittent bug in Next LS v0.23.3 where `textDocument/definition` requests can fail with:
-```
-Protocol.UndefinedError: protocol Enumerable not implemented for :timeout of type Atom
-```
-
-This bug is tracked in [Next LS Issue #543](https://github.com/elixir-tools/next-ls/issues/543) and primarily occurs in CI environments. The affected test (`test_request_defining_symbol_none`) is marked as expected to fail until this upstream bug is resolved.
+This directory contains the integration for Elixir language support using [Expert](https://github.com/elixir-lang/expert), the official Elixir language server.
 
 ## Prerequisites
 
@@ -22,9 +10,10 @@ Before using the Elixir language server integration, you need to have:
    - Install from: https://elixir-lang.org/install.html
    - Verify with: `elixir --version`
 
-2. **Next LS** installed and available in your PATH
-   - Install from: https://github.com/elixir-tools/next-ls#installation
-   - Verify with: `nextls --version`
+2. **Expert** (optional - will be downloaded automatically if not found)
+   - Expert binaries are automatically downloaded from GitHub releases
+   - Manual installation: https://github.com/elixir-lang/expert#installation
+   - If installed manually, ensure `expert` is in your PATH
 
 ## Features
 
@@ -42,13 +31,20 @@ The Elixir integration provides:
 
 ## Configuration
 
-The integration uses the default Next LS configuration with:
+The integration uses the default Expert configuration with:
 
 - **MIX_ENV**: `dev`
 - **MIX_TARGET**: `host`
 - **Experimental completions**: Disabled by default
 - **Credo extension**: Enabled by default
 
+### Version Management (asdf)
+
+Expert automatically respects project-specific Elixir versions when using asdf:
+- If a `.tool-versions` file exists in the project root, Expert will use the specified Elixir version
+- Expert is launched from the project directory, allowing it to pick up project configuration
+- No additional configuration needed - just ensure asdf is installed and the project has a `.tool-versions` file
+
 ## Usage
 
 The Elixir language server is automatically selected when working with Elixir projects. It will be used for:
@@ -63,14 +59,14 @@ The Elixir language server is automatically selected when working with Elixir pr
 
 ### Important: Project Compilation
 
-Next LS requires your Elixir project to be **compiled** for optimal performance, especially for:
+Expert requires your Elixir project to be **compiled** for optimal performance, especially for:
 - Cross-file reference resolution
 - Complete symbol information
 - Accurate go-to-definition
 
 **For production use**: Ensure your project is compiled with `mix compile` before using the language server.
 
-**For testing**: The test suite automatically compiles the test repositories before running tests to ensure optimal Next LS performance.
+**For testing**: The test suite automatically compiles the test repositories before running tests to ensure optimal Expert performance.
 
 ## Testing
 
@@ -83,8 +79,9 @@ pytest test/solidlsp/elixir/ -m elixir
 ## Implementation Details
 
 - **Main class**: `ElixirTools` in `elixir_tools.py`
-- **Initialization parameters**: Defined in `initialize_params.json`
 - **Language identifier**: `"elixir"`
-- **Command**: `nextls --stdio`
+- **Command**: `expert --stdio`
+- **Supported platforms**: Linux (x64, arm64), macOS (x64, arm64), Windows (x64, arm64)
+- **Binary distribution**: Downloaded from [GitHub releases](https://github.com/elixir-lang/expert/releases)
 
-The implementation follows the same patterns as other language servers in this project, inheriting from `SolidLanguageServer` and providing Elixir-specific configuration and behavior. 
+The implementation follows the same patterns as other language servers in this project, inheriting from `SolidLanguageServer` and providing Elixir-specific configuration and behavior.