Allow configuring exec args (e.g. --max-old-space-size) for ESLint LSP

[reekystive]

The Issue

Currently, the Node.js argument --max-old-space-size=8192 is hardcoded in crates/languages/src/typescript.rs for launching the ESLint language server.

For large repositories, 8 GB of memory may not be sufficient, and there is no existing way for users to adjust Node.js arguments used by the ESLint LSP process.

Zed already supports a global Node configuration at the top level:

"node": {
  "path": "/path/to/node"
}

This applies to all Node-based LSP servers such as ESLint and vtsls.

For vtsls, users can further configure Node.js-related settings via:

"vtsls": {
  "settings": {
    "typescript": {
      "tsserver": {
        "maxTsServerMemory": 80000,
        "nodePath": "/another/path/to/node"
      }
    }
  }
}

This allows users to fine-tune the TypeScript server’s memory usage and runtime path, with the specified runtime path taking precedence over the global node.path setting.

However, there is currently no equivalent configuration for the ESLint LSP, making it impossible to adjust its Node.js memory limit. While the global runtime can be changed via the node.path setting, there is no way to modify the memory limit — either globally or locally.

---

Proposal

Add support for per-server Node.js configuration for ESLint (and potentially other Node-based LSPs), for example:

"lsp": {
  "eslint": {
    "settings": {
      "execArgv": ["--max-old-space-size=80000"],
      "runtime": "/path/to/node"
    }
  }
}

Proposed keys

• execArgv: Allows specifying arbitrary Node.js arguments (e.g. memory limits or debug flags).
• runtime: Allows specifying the Node.js executable path (useful for environments managed by nvm, Volta, etc.).

Benefits

• Enables using different Node.js versions for specific LSP servers if needed.
• Allows allocating more memory for ESLint in large projects, without affecting other tools.
• Provides granular control similar to what’s already supported for vtsls.

---

Motivation

• Large or complex repositories often require increasing Node.js memory limits beyond 8 GB.
• Many development environments manage multiple Node.js versions (nvm, Volta, asdf) and need flexibility in runtime selection.
• Aligning ESLint’s configuration capabilities with vtsls improves consistency and user control across Node-based language servers.

---

Relevant code location:

zed/crates/languages/src/typescript.rs

Lines 592 to 598 in 35f5eb1

	fn eslint_server_binary_arguments(server_path: &Path) -> Vec<OsString> {
	vec![
	"--max-old-space-size=8192".into(),
	server_path.into(),
	"--stdio".into(),
	]
	}