fix(lsp): prevent infinite loop on EOF (#15)

* fix(lsp): prevent infinite loop on EOF in header reading

When stdin reaches EOF, read_line returns an empty string. The loop
only checked for "\r\n" or "\n" to break, causing infinite warnings
when running mcpls manually without proper MCP input.

Now returns ServerTerminated error on EOF, breaking the loop cleanly.

* docs: add rust-analyzer installation prerequisites

* chore(release): prepare v0.2.1

- Bump version to 0.2.1
- Update CHANGELOG with bug fix and docs improvements

Author: bug-ops

CHANGELOG.md

@@ -7,6 +7,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.2.1] - 2025-12-27
+
+Patch release with bug fix and documentation improvements.
+
+### Fixed
+
+- **Infinite loop on EOF** — Fixed infinite warning loop when LSP server terminates or stdin reaches EOF. Now returns `ServerTerminated` error cleanly instead of flooding logs with "Malformed header" warnings.
+
+### Added
+
+- **Prerequisites section in README** — Added rust-analyzer installation instructions with multiple methods (rustup, Homebrew, package managers). Includes important note about "LSP server process terminated unexpectedly" error when language server is missing.
+
 ## [0.2.0] - 2025-12-27
 
 Enhanced LSP features release with 5 new MCP tools for advanced code intelligence.
@@ -276,6 +288,7 @@ Add to `~/.claude/mcp.json`:
 - Workspace auto-discovery
 - LSP server auto-detection and installation
 
-[Unreleased]: https://github.com/bug-ops/mcpls/compare/v0.2.0...HEAD
+[Unreleased]: https://github.com/bug-ops/mcpls/compare/v0.2.1...HEAD
+[0.2.1]: https://github.com/bug-ops/mcpls/compare/v0.2.0...v0.2.1
 [0.2.0]: https://github.com/bug-ops/mcpls/compare/v0.1.0...v0.2.0
 [0.1.0]: https://github.com/bug-ops/mcpls/releases/tag/v0.1.0

Cargo.lock

@@ -3,7 +3,7 @@ members = ["crates/*"]
 resolver = "2"
 
 [workspace.package]
-version = "0.2.0"
+version = "0.2.1"
 edition = "2024"
 rust-version = "1.85"
 authors = ["Andrei G. <k05h31@gmail.com>"]
@@ -23,7 +23,7 @@ clap = "4.5"
 dirs = "6.0"
 futures = "0.3"
 lsp-types = "0.97"
-mcpls-core = { path = "crates/mcpls-core", version = "0.2.0" }
+mcpls-core = { path = "crates/mcpls-core", version = "0.2.1" }
 predicates = "3.1"
 rmcp = "0.12"
 rstest = "0.26"

Cargo.toml

@@ -24,7 +24,26 @@ AI coding assistants are remarkably capable, but they're working blind. They see
 - **Safe refactoring** — Rename symbols with confidence, workspace-wide
 
 > [!TIP]
-> Zero configuration for Rust projects. Just install and go — rust-analyzer works out of the box.
+> Zero configuration for Rust projects. Just install mcpls and a language server — ready to go.
+
+## Prerequisites
+
+For Rust projects, install rust-analyzer:
+
+```bash
+# Via rustup (recommended)
+rustup component add rust-analyzer
+
+# Or via Homebrew (macOS)
+brew install rust-analyzer
+
+# Or via package manager (Linux)
+# Ubuntu/Debian: sudo apt install rust-analyzer
+# Arch: sudo pacman -S rust-analyzer
+```
+
+> [!IMPORTANT]
+> mcpls requires a language server to be installed. Without rust-analyzer, you'll see "LSP server process terminated unexpectedly" errors.
 
 ## Installation
 

README.md

@@ -118,6 +118,11 @@ impl LspTransport {
             line.clear();
             self.stdout.read_line(&mut line).await?;
 
+            // EOF - stream closed
+            if line.is_empty() {
+                return Err(Error::ServerTerminated);
+            }
+
             if line == "\r\n" || line == "\n" {
                 break;
             }