### Complete nixd Configuration Example

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/configuration.md

This is a comprehensive example of a nixd configuration file, demonstrating settings for nixpkgs, formatting, options (NixOS, Home Manager), and diagnostics.

```jsonc
{
  "nixpkgs": {
    // For flake.
    // "expr": "import (builtins.getFlake \"/home/lyc/workspace/CS/OS/NixOS/flakes\").inputs.nixpkgs { }   "

    // This expression will be interpreted as "nixpkgs" toplevel
    // Nixd provides package, lib completion/information from it.
    ///
    // Resource Usage: Entries are lazily evaluated, entire nixpkgs takes 200~300MB for just "names".
    ///                Package documentation, versions, are evaluated by-need.
    "expr": "import <nixpkgs> { }"
  },
  "formatting": {
    // Which command you would like to do formatting
    "command": [ "nixfmt" ]
  },
  // Tell the language server your desired option set, for completion
  // This is lazily evaluated.
  "options": { // Map of eval information
      // By default, this entriy will be read from `import <nixpkgs> { }`
      // You can write arbitary nix expression here, to produce valid "options" declaration result.
      //
      // *NOTE*: Replace "<name>" below with your actual configuration name.
      // If you're unsure what to use, you can verify with `nix repl` by evaluating
      // the expression directly.
      //
      "nixos": {
          "expr": "(builtins.getFlake (builtins.toString ./.)).nixosConfigurations.<name>.options"
      },

    // Before configuring Home Manager options, consider your setup:
    // Which command do you use for home-manager switching?
    //
    //  A. home-manager switch --flake .#...
    //  B. nixos-rebuild switch --flake .#...
    //
    // Configuration examples for both approaches are shown below.
    "home-manager": {
      // A:
      "expr": "(builtins.getFlake (builtins.toString ./.)).homeConfigurations.<name>.options"

      // B:
      "expr": "(builtins.getFlake (builtins.toString ./.)).nixosConfigurations.<name>.options.home-manager.users.type.getSubOptions []"
    }
  },
  // Control the diagnostic system
  "diagnostic": {
    "suppress": [
      "sema-extra-with"
    ]
  }
}
```

--------------------------------

### Option Information Output for binfmtMiscRegistrations

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/option-info.md

This is an example output from `nixd-attrset-eval` when querying `boot.binfmtMiscRegistrations`. It shows that the option has no default or example defined, and provides its description and type information.

```text
CHECK:          "Default": null,
CHECK-NEXT:     "Definitions": [],
CHECK-NEXT:     "Description": "Alias of {option}`boot.binfmt.registrations`.",
CHECK-NEXT:     "Example": null,
CHECK-NEXT:     "Type": {
CHECK-NEXT:        "Description": "attribute set of (submodule)",
CHECK-NEXT:        "Name": "attrsOf"
CHECK-NEXT:     }

```

--------------------------------

### Install Project with Ninja

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/dev.md

Install the compiled nixd project using Ninja. This is required before launching an editor for testing.

```bash
ninja -C build install
```

--------------------------------

### Start Neovim Test Environment

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/editors/editors.md

Use this command to launch a Neovim instance with LSP support for testing.

```console
nix develop github:nix-community/nixd#nvim

nvim-lsp .
```

--------------------------------

### Install nixd using nix-env (NixOS)

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/editor-setup.md

Installs the nixd package using legacy nix-env commands on NixOS.

```console
nix-env -iA nixos.nixd
```

--------------------------------

### Basic nixf-tidy Usage Example

Source: https://github.com/nix-community/nixd/blob/main/libnixf/README.md

Shows a simple command to pipe Nix code into `nixf-tidy` for variable lookup analysis.

```bash
cat foo.nix | nixf-tidy --variable-lookup
```

--------------------------------

### Start VSCodium Test Environment

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/editors/editors.md

Use this command to launch a VSCodium instance with the vscode-nix-ide plugin for testing.

```console
nix develop github:nix-community/nixd#vscodium

codium-test .
```

--------------------------------

### Query Option Information for kernelModules

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/option-info.md

This JSON RPC request uses the `attrset/optionInfo` method to get details for the `boot.kernelModules` option. This is useful for understanding how to configure kernel modules, including their default and example values.

```json
{
   "jsonrpc":"2.0",
   "id":2,
   "method":"attrset/optionInfo",
   "params": [ "boot", "kernelModules" ]
}

```

--------------------------------

### Initialize Nixd Language Server

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/extract-to-file/extract-with-free-vars.md

Initializes the nixd language server with workspace capabilities. This is a standard setup for LSP clients.

```json
{
   "jsonrpc":"2.0",
   "id":0,
   "method":"initialize",
   "params":{
      "processId":123,
      "rootPath":"",
      "capabilities":{
         "workspace": {
            "workspaceEdit": {
               "documentChanges": true,
               "resourceOperations": ["create", "rename", "delete"]
            }
         }
      },
      "trace":"off"
   }
}
```

--------------------------------

### Option Information Output for kernelModules

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/option-info.md

This output shows the information for `boot.kernelModules`. Notably, it displays a string representation of the example value, which is preferred over a raw list default to prevent deep recursion issues.

```text
CHECK:          "Default": null,
CHECK-NEXT:     "Definitions": [],
CHECK-NEXT:     "Description": "The set of kernel modules to be loaded in the second stage of the boot process.",
CHECK-NEXT:     "Example": "[ \"kvm-intel\" \"snd_hda_intel\" ]",
CHECK-NEXT:     "Type": {

```

--------------------------------

### Install nixd using nix-env (Non-NixOS)

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/editor-setup.md

Installs the nixd package using legacy nix-env commands on non-NixOS systems.

```console
nix-env -iA nixpkgs.nixd
```

--------------------------------

### Install nixd using nix profile

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/editor-setup.md

Adds the nixd package to your user profile using the nix profile command.

```console
nix profile add github:nixos/nixpkgs#nixd
```

--------------------------------

### Request Option Info for 'boot.tmp.cleanOnBoot'

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/option-info.md

Send a JSON-RPC request to get information about the 'boot.tmp.cleanOnBoot' option. This is used to test how the tool handles options with scalar defaults and no examples.

```json
{
   "jsonrpc":"2.0",
   "id":4,
   "method":"attrset/optionInfo",
   "params": [ "boot", "tmp", "cleanOnBoot" ]
}
```

--------------------------------

### Nixd Completion Response for Option with Example and Default

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/completion/options-default.md

The expected completion response from nixd when an option has both 'example' and 'defaultText'. It shows two distinct items, sorted by 'sortText'.

```json
{
     "id": 1,
     "jsonrpc": "2.0",
     "result": {
       "isIncomplete": false,
       "items": [
         {
           "data": "",
           "detail": "nixos | bool (boolean)",
           "documentation": null,
           "filterText": "bar",
           "insertText": "bar = ${1:true};",
           "insertTextFormat": 2,
           "kind": 4,
           "label": "bar (example)",
           "score": 0,
           "sortText": "0bar",
           "textEdit": {
             "newText": "bar = ${1:true};",
             "range": {
               "end": {
                 "character": 17,
                 "line": 0
               },
               "start": {
                 "character": 15,
                 "line": 0
               }
             }
           }
         },
         {
           "data": "",
           "detail": "nixos | bool (boolean)",
           "documentation": null,
           "filterText": "bar",
           "insertText": "bar = ${1:pkgs.stdenv.hostPlatform.isLinux};
           "insertTextFormat": 2,
           "kind": 4,
           "label": "bar (default)",
           "score": 0,
           "sortText": "1bar",
           "textEdit": {
             "newText": "bar = ${1:pkgs.stdenv.hostPlatform.isLinux};",
             "range": {
               "end": {
                 "character": 17,
                 "line": 0
               }
               "start": {
                 "character": 15,
                 "line": 0
               }
             }
           }
         }
       ]
     }
}
```

--------------------------------

### Configure Project with Meson

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/dev.md

Configure the nixd project using Meson. Use `--buildtype=debug` for development, `--prefix=` for non-privileged installation, `--default-library=static` to avoid RPATH issues, and `-Dwerror=true` to match CI settings.

```bash
meson setup build --buildtype=debug --default-library=static --prefix=$PWD/local/install -Dwarning_level=3 -Dwerror=true
```

--------------------------------

### Neovim nixd LSP Configuration

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/configuration.md

Configure the nixd LSP client in Neovim using vim.lsp.config. This example sets up the command, filetypes, root markers, and specific settings for nixpkgs, formatting, and options.

```lua
local nvim_lsp = vim.lsp
vim_lsp.config("nixd", {
  cmd = { "nixd" },
  filetypes = { "nix" },
  root_markers = { "flake.nix", ".git" },
  settings = {
    nixd = {
      nixpkgs = {
        expr = "import <nixpkgs> { }",
      },
      formatting = {
        command = { "nixfmt" },
      },
      options = {
        nixos = {
          expr = '(builtins.getFlake (toString ./.)).nixosConfigurations.<hostname>.options',
        },
        home_manager = {
          expr = '(builtins.getFlake (toString ./.)).homeConfigurations."<username>@<hostname>".options',
        },
      },
    },
  },
})
vim_lsp.enable("nixd")
```

--------------------------------

### Request Code Action for Noogle Documentation

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/noogle-doc/noogle-lib-simple.md

Requests a code action for a specific range within a Nix file. This example specifically triggers the 'Open Noogle documentation' action.

```json
{
   "jsonrpc":"2.0",
   "id":2,
   "method":"textDocument/codeAction",
   "params":{
      "textDocument":{
         "uri":"file:///noogle-lib-simple.nix"
      },
      "range":{
         "start":{
            "line": 0,
            "character":0
         },
         "end":{
            "line":0,
            "character":18
         }
      },
      "context":{
         "diagnostics":[],
         "triggerKind":2
      }
   }
}
```

--------------------------------

### Evaluate Nix Expression with Documentation

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/attrs-info-doc.md

Send a JSON-RPC request to evaluate a Nix expression. This example includes an attribute with embedded markdown documentation.

```json
{
   "jsonrpc":"2.0",
   "id":0,
   "method":"attrset/evalExpr",
   "params": "{ hello = /** some markdown docs */x: y: x; }"
}
```

--------------------------------

### Request References for 'foo'

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/references/with.md

Requests references for the identifier 'foo' within the 'basic.nix' file. The position is set to the start of 'foo'.

```json
{
   "jsonrpc":"2.0",
   "id":2,
   "method":"textDocument/references",
   "params":{
      "textDocument":{
         "uri":"file:///basic.nix"
      },
      "position":{
        "line": 0,
        "character":3
      }
   }
}
```

--------------------------------

### Configuring Home Manager Options (Standalone) in nixd

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/configuration.md

For users with a standalone Home Manager setup not integrated with NixOS, use this configuration to provide Home Manager options to nixd. Ensure the paths to your Home Manager configuration and nixpkgs are correct.

```jsonc
{
  "options": {
    "home-manager": {
      "expr": "(import <home-manager/modules> { configuration = ~/.config/home-manager/home.nix; pkgs = import <nixpkgs> {}; }).options"
    }
  }
}
```

--------------------------------

### Open Nix file with nested with statements

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/with-to-let/with-to-let-indirect-lambda.md

Opens a Nix file containing nested 'with' statements, one of which is within a lambda. This setup is used to test code action behavior.

```nix
with outer; x: with inner; baz
```

--------------------------------

### Query Option Information for binfmtMiscRegistrations

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/option-info.md

This JSON RPC request targets the `attrset/optionInfo` method to retrieve detailed information about the `boot.binfmtMiscRegistrations` option. It's used to inspect an option's description, type, default value, and examples.

```json
{
   "jsonrpc":"2.0",
   "id":1,
   "method":"attrset/optionInfo",
   "params": [ "boot", "binfmtMiscRegistrations" ]
}

```

--------------------------------

### Retrieve Home-Manager Options in NixOS Module

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/configuration.md

Use this expression to get home-manager options when your home-manager is installed as part of a NixOS module. Replace `<name>` with your actual configuration name.

```nix
(builtins.getFlake (builtins.toString ./.)).nixosConfigurations.<name>.options.home-manager.users.type.getSubOptions []
```

--------------------------------

### Open Nix File for Hover Test

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/hover/value-docs.md

Simulates opening a Nix file named 'basic.nix' containing a reference to 'pkgs.myFunc'. This prepares the environment for the hover request.

```nix
pkgs.myFunc
```

--------------------------------

### Initialize Nixd Language Server

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs-shallow-bulk.md

Initializes the nixd language server with basic parameters.

```json
{
   "jsonrpc":"2.0",
   "id":0,
   "method":"initialize",
   "params":{
      "processId":123,
      "rootPath":"",
      "capabilities":{},
      "trace":"off"
   }
}
```

--------------------------------

### Option Information Output for kernelPackages

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/option-info.md

This output for `boot.kernelPackages` illustrates that when both `default` and `defaultText` are present, `defaultText` is prioritized. This ensures that a user-friendly representation is shown instead of a placeholder.

```text
CHECK:          "Default": "pkgs.linuxPackages",
CHECK-NEXT:     "Definitions": [],
CHECK-NEXT:     "Description": "The kernel packages set.",
CHECK-NEXT:     "Example": null,

```

--------------------------------

### Open Nix File with Package Selection

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/definition/select-package.md

This section demonstrates opening a Nix file containing a package selection expression (`pkgs.x`) for definition lookup.

```nix
pkgs.x
```

--------------------------------

### Install nixd on NixOS

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/editor-setup.md

Add the nixd package to your system's environment for use on NixOS.

```nix
{
  pkgs, ...
}: {
  environment.systemPackages = with pkgs;
  [ nixd ];
}
```

--------------------------------

### Nix Indented String Example

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/rewrite-string/to-dquote-newline.md

A Nix code snippet demonstrating an indented string with a newline character.

```nix
{ x = ''hello
world''; }
```

--------------------------------

### nixf-tidy CLI Options

Source: https://github.com/nix-community/nixd/blob/main/libnixf/README.md

Lists the available command-line options for the `nixf-tidy` tool, used for linting Nix projects.

```text
nixf-tidy

--pretty-print  Pretty print the JSON data
--variable-lookup  Peform Variable Lookup Analysis on the source code, including detecting dead code, and unused variables.

```

--------------------------------

### Configure Coc.nvim for nixd

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/editor-setup.md

Set up coc-settings.json to use nixd as the language server for Nix files.

```jsonc
{
  "languageserver": {
    "nix": {
      "command": "nixd",
      "filetypes": ["nix"]
    }
  }
}
```

--------------------------------

### TextDocument DidOpen Notification

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/hover/empty-payload.md

Sent to the language server when a text document is opened by the client. This example opens a Nix file.

```nix
pkgs.undocumented
```

--------------------------------

### Request Inlay Hints

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/inlay-hint.md

Requests inlay hints for a specific range in a Nix file. The response will contain hints like package versions.

```json
{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "textDocument/inlayHint",
    "params": {
        "textDocument":{
            "uri":"file:///basic.nix"
        },
        "range": {
          "start":{
            "line": 0,
            "character":0
          },
          "end":{
            "line":0,
            "character":20
          }
        }
    }
}
```

--------------------------------

### Request Document Highlights

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/document-highlight/fail.md

Requests document highlights for a specific position in a Nix file. This example demonstrates a scenario where no highlights are expected.

```json
{
   "jsonrpc":"2.0",
   "id":2,
   "method":"textDocument/documentHighlight",
   "params":{
      "textDocument":{
         "uri":"file:///basic.nix"
      },
      "position":{
        "line": 0,
        "character":1
      }
   }
}
```

--------------------------------

### Open Nix File

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/definition/let-in.md

Simulates opening a Nix file with a simple let-in expression. This is a prerequisite for requesting definitions.

```nix
let x = 1; in x
```

--------------------------------

### Configure Kakoune-lsp for nixd

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/editor-setup.md

Set up Kakoune-lsp hooks to enable nixd for Nix filetypes, specifying root globs.

```kakscript
remove-hooks global lsp-filetype-nix
hook -group lsp-filetype-nix global BufSetOption filetype=nix %{
    set-option buffer lsp_servers %{
        [nixd]
        root_globs = ["flake.nix", "shell.nix", ".git", ".hg"]
    }
}
```

--------------------------------

### DidOpen Notification for Nix File

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/rename/issue-255-1.md

Notifies the language server that a Nix file has been opened. This allows the server to start analyzing the file.

```nix
{a ? 1}: { x = a; }
```

--------------------------------

### Open Nix File for Code Action

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/rewrite-string/to-indented.md

Opens a Nix file with a simple string assignment to trigger code actions. The file content is `{ x = "hello"; }`.

```nix
{ x = "hello"; }
```

--------------------------------

### DidOpen TextDocument Notification

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/completion/select.md

A notification sent to the language server when a text document is opened. This example shows a Nix file with partial input.

```nix
pkgs.hel
```

--------------------------------

### Query Option Information for kernelPackages

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/option-info.md

This JSON RPC request queries the `attrset/optionInfo` method for the `boot.kernelPackages` option. It demonstrates how the tool handles options that have both a raw default and a `defaultText` field.

```json
{
   "jsonrpc":"2.0",
   "id":3,
   "method":"attrset/optionInfo",
   "params": [ "boot", "kernelPackages" ]
}

```

--------------------------------

### Verify Definition Response

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/definition/inherit.md

Uses FileCheck to verify that the definition response from nixd correctly identifies the start and end range of the 'x' symbol.

```shell
     CHECK:  "id": 2,
CHECK-NEXT:  "jsonrpc": "2.0",
CHECK-NEXT:  "result": {
CHECK-NEXT:    "range": {
CHECK-NEXT:      "end": {
CHECK-NEXT:        "character": 5,
CHECK-NEXT:        "line": 0
CHECK-NEXT:      },
CHECK-NEXT:      "start": {
CHECK-NEXT:        "character": 4,
CHECK-NEXT:        "line": 0
CHECK-NEXT:      }
CHECK-NEXT:    },

```

--------------------------------

### Open Nix File for Hover

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/hover/package-select.md

Opens a Nix file containing a package reference. This action makes the file content available to the language server for analysis.

```nix
pkgs.foo
```

--------------------------------

### Request Hover Information for Nix Function

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/hover/value-docs.md

Requests hover information for the 'myFunc' symbol in 'basic.nix'. The position is set to the start of the symbol to ensure accurate retrieval.

```json
{
   "jsonrpc":"2.0",
   "id":2,
   "method":"textDocument/hover",
   "params":{
      "textDocument":{
         "uri":"file:///basic.nix"
      },
      "position":{
         "line":0,
         "character":5
      }
   }
}
```

--------------------------------

### Open Nix File for Code Action

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/attr-name/quote-let.md

Opens a Nix file with a simple let-in expression. This prepares the file for subsequent code action requests.

```nix
let foo = 1; in foo
```

--------------------------------

### Open Nix File for Code Action Test

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/add-to-formals/already-defined-negative.md

Opens a Nix file named 'already-defined.nix' with the content '{x}: x'. This sets up the context for testing code actions.

```nix
{x}: x
```

--------------------------------

### Complete Attribute Set Keys

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/attrs-completion.md

Send a JSON-RPC request to get completion suggestions for attribute set keys. Provide a scope and a prefix to filter the suggestions.

```json
{
   "jsonrpc":"2.0",
   "id":1,
   "method":"attrset/attrpathComplete",
   "params": {
        "Scope": [ ],
        "Prefix": "py"
   }
}
```

--------------------------------

### TextDocument Completion Request

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/completion/select.md

A request to the language server for completion suggestions at a specific position in a text document. This example targets the partial input 'hel' in a Nix file.

```json
{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "textDocument/completion",
    "params": {
        "textDocument": {
            "uri": "file:///completion.nix"
        },
        "position": {
            "line": 0,
            "character": 7
        },
        "context": {
            "triggerKind": 1
        }
    }
}
```

--------------------------------

### Configure KDE Kate LSP Client for nixd

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/editor-setup.md

Configure the LSP Client plugin in KDE Kate to use nixd for Nix files.

```jsonc
{
  "servers": {
    "nix": {
      "command": ["nixd"],
      "url": "https://github.com/nix-community/nixd",
      "highlightingModeRegex": "^Nix$"
    }
  }
}
```

--------------------------------

### Nixd Code Action Response (Quick Fix)

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/quick-fix/quick-fix.md

The expected response from nixd when a code action, specifically a quick fix, is requested. This example shows the 'insert */' quick fix.

```json
{
     "id": 2,
     "jsonrpc": "2.0",
     "result": [
       {
         "edit": {
           "changes": {
             "file:///basic.nix": [
               {
                 "newText": "*/",
                 "range": {
                   "end": {
                     "character": 2,
                     "line": 0
                   },
                   "start": {
                     "character": 2,
                     "line": 0
                   }
                 }
               }
             ]
           }
         },
         "kind": "quickfix",
         "title": "insert */"
       }
     ]
   }
```

--------------------------------

### Initialize Request

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/initialize.md

Sends an 'initialize' request to the nixd server. This is the first step in establishing a connection and should include process ID, root path, client capabilities, and trace level.

```json
{
   "jsonrpc":"2.0",
   "id":0,
   "method":"initialize",
   "params":{
      "processId":123,
      "rootPath":"",
      "capabilities":{ },
      "trace":"off"
   }
}
```

--------------------------------

### Diagnose Nix Expression Issues in Nix REPL

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/configuration.md

Test your Nix expressions in `nix repl` to diagnose evaluation issues. This example shows how to inspect NixOS configuration options.

```nix
nix-repl> (builtins.getFlake (builtins.toString ./.)).nixosConfigurations.<name>.options
error: syntax error, unexpected SPATH, expecting ID or OR_KW or DOLLAR_CURLY or '"'
  at «string»:1:65:
       1| (builtins.getFlake (builtins.toString ./.)).nixosConfigurations.<name>.options
        |                                                                 ^
```

```nix
nix-repl> (builtins.getFlake (builtins.toString ./.)).nixosConfigurations.adrastea.options
{
  _module = { ... };
  appstream = { ... };
  assertions = { ... };
  boot = { ... };
  # ... more options ..., this is expected.
}
```

--------------------------------

### Nix Syntax Error Example (Missing Semicolon)

Source: https://github.com/nix-community/nixd/blob/main/libnixf/README.md

Illustrates a common Nix syntax error where a missing semicolon after a value can lead to unexpected parsing behavior in the official parser.

```nix
{
    a = 1
    b = 2
}
```

--------------------------------

### Initialize Nixd Language Server

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/add-to-formals/already-defined-negative.md

Sends an initialize request to the nixd language server. This is a standard first step in LSP communication.

```json
{
   "jsonrpc":"2.0",
   "id":0,
   "method":"initialize",
   "params":{
      "processId":123,
      "rootPath":"",
      "capabilities":{
      },
      "trace":"off"
   }
}
```

--------------------------------

### Open Nix File with Quoted Underscore Attribute

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/attr-name/unquote-underscore.md

Opens a Nix file containing an attribute name enclosed in quotes that starts with an underscore. This sets up the scenario for the code action.

```nix
{ "_private" = 1; }
```

--------------------------------

### Initialize Nixd Language Server

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/convert-to-inherit/convert-to-inherit-with-default.md

Sends an initialize request to the Nixd language server. This is a standard first step in LSP communication.

```json
{
   "jsonrpc":"2.0",
   "id":0,
   "method":"initialize",
   "params":{
      "processId":123,
      "rootPath":"",
      "capabilities":{ 
      },
      "trace":"off"
   }
}
```

--------------------------------

### Open Nix File for Code Actions

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs-multiple-prefixes-foo.md

Opens a Nix file containing multiple attribute sets ('foo' and 'bar') for analysis. This sets up the context for testing code actions.

```nix
{ foo.a = 1; foo.b = 2; bar.c = 3; bar.d = 4; }
```

--------------------------------

### Compile Project with Meson

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/dev.md

Compile the nixd project after configuration using Meson.

```bash
meson compile -C build
```

--------------------------------

### Open Nix File with Sibling Inherit

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs-sibling-inherit.md

Opens a Nix file containing an attribute set with a dotted path and an `inherit` binding for a sibling. This setup is used to test the 'pack-attrs' code action.

```nix
{ foo.bar = 1; inherit baz; }
```

--------------------------------

### Open Nix File with Inherit Conflict

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs-inherit-conflict.md

Opens a Nix file that contains a conflicting 'inherit' statement and a dotted path assignment. This setup is used to test the 'Pack' code action behavior.

```nix
{ inherit foo; foo.bar = 1; }
```

--------------------------------

### Open Nix File for Definition Test

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/definition/builtin.md

Opens a Nix file named 'basic.nix' containing the keyword 'builtins' to prepare for a definition request.

```nix
builtins
```

--------------------------------

### Request Code Action for Dotted Path

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs.md

Requests code actions for a specific range within a Nix file. This example targets the dotted path 'foo.bar' to trigger the 'Pack dotted path' action.

```json
{
   "jsonrpc":"2.0",
   "id":2,
   "method":"textDocument/codeAction",
   "params":{
      "textDocument":{
         "uri":"file:///pack-attrs.nix"
      },
      "range":{
         "start":{
            "line": 0,
            "character":2
         },
         "end":{
            "line":0,
            "character":9
         }
      },
      "context":{
         "diagnostics":[],
         "triggerKind":2
      }
   }
}
```

--------------------------------

### Open Nix File for Diagnostics

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/diagnostic/liveness.md

Opens a Nix file with the URI 'file:///basic.nix' to trigger diagnostics. The expected output checks for an empty diagnostics list and the file's URI and version.

```nix
x: y: x + 1
```

```text
     CHECK: "diagnostics": [],
CHECK-NEXT: "uri": "file:///basic.nix",
CHECK-NEXT: "version": 1
```

--------------------------------

### Open Nix File for Definition Test

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/definition/path.md

Opens a Nix file in the language server to prepare for definition requests. The file URI includes a placeholder for the test directory.

```nix
file://TEST_DIR/main.nix
./target.nix
```

--------------------------------

### Open Nix File with Invalid Let Binding

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/attr-name/unquote-let-invalid.md

Opens a Nix file containing a let binding with an invalid identifier (quoted string starting with a digit). This is used to test code action behavior.

```nix
let "123" = 1; in x

```

--------------------------------

### Open Nix File with Conflicting Bindings

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs-conflict.md

Opens a Nix file containing a conflict: a simple binding 'foo' and a dotted path 'foo.bar'. This setup is used to test the 'Pack' code action behavior.

```nix
{ foo = 1; foo.bar = 2; }
```

--------------------------------

### Open Nix File for Analysis

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/with-to-let/with-to-let-indirect-attrset.md

Opens a Nix file for the language server to analyze. This file contains nested `with` statements.

```nix
with outer; { y = with inner; bar; }
```

--------------------------------

### Open Nix File for Testing

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/noogle-doc/noogle-not-lib.md

Opens a Nix file named 'noogle-not-lib.nix' for the language server. This prepares the environment for subsequent code action requests.

```nix
pkgs.hello
```

--------------------------------

### JSON RPC Request for Option Completion

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/option-complete.md

A JSON RPC request to get completion suggestions for options within a specified scope. The 'Scope' parameter filters the search, and 'Prefix' can be used for partial matching.

```json
{
   "jsonrpc":"2.0",
   "id":1,
   "method":"attrset/optionComplete",
   "params": { "Scope": [ "boot" ], "Prefix": "" }
}

```

--------------------------------

### Open Nix File

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/hover/1.md

Opens a basic Nix file named 'basic.nix' with content '{ a = 1; }' in the language server. This prepares the server to process requests related to this file.

```nix
{ a = 1; }
```

--------------------------------

### Send JSON-RPC Request for Attribute Path Info

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd-attrset-eval/test/attrs-info.md

Send a JSON-RPC request to the `attrset/attrpathInfo` method to get information about a specific attribute path within an attribute set. The attribute path is provided as a string.

```json
{
   "jsonrpc":"2.0",
   "id":1,
   "method":"attrset/attrpathInfo",
   "params": [ "hello" ]
}
```

--------------------------------

### Open Nix File for Testing

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/convert-to-inherit/convert-to-inherit-selector-mismatch.md

Opens a Nix file in the language server to enable code analysis. The content is a simple attribute set.

```nix
{ foo = lib.bar; }
```

--------------------------------

### Open Nix File for Hover Test

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/hover/options.md

This code block represents opening a Nix file named 'basic.nix' with content `{ foo.bar = 1 }`. This is a prerequisite for testing hover functionality.

```nix
{ foo.bar = 1 }
```

--------------------------------

### Nix Code for Pack Attributes Test

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs-bulk-quoted.md

This Nix code defines attributes where one key, "1foo", starts with a digit and thus requires quoting. This serves as input for testing the pack attributes code actions.

```nix
{ "1foo".a = 1; "1foo".b = 2; }
```

--------------------------------

### Initialize LSP Client

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/completion/options-in-config.md

Sends an initialize request to the Language Server Protocol client.

```json
{
   "jsonrpc":"2.0",
   "id":0,
   "method":"initialize",
   "params":{
      "processId":123,
      "rootPath":"",
      "capabilities":{
      },
      "trace":"off"
   }
}
```

--------------------------------

### Open Nix File for Folding Range Analysis

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/folding-range/basic.md

Opens a Nix file with sample attribute sets and lists for testing folding range functionality. This snippet defines the content that will be analyzed.

```nix
{
  # Multi-line attribute set
  attrs = {
    x = 1;
    y = 2;
  };

  # Multi-line list
  list = [
    1
    2
  ];
}
```

--------------------------------

### Attribute name coloring for nested attributes

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/features.md

This example demonstrates how semantic tokens can differentiate between attribute paths that create nested attribute sets (like `foo.bar`) and those that create new entries within an existing set (like `foo.x`). The goal is to visually distinguish these structures.

```nix
{
    foo.bar = 1;
#   ~~~ ~~~ <----- these two tokens should be colored as same
    foo.x = 2;
#   ~~~     <----- this token, however will not be colored as same as "foo.bar"
}
```

```nix
{
    foo = {
#   ^~~  <-------- new !
        bar = 1;
        #  <------- new !
    };
}
```

```nix
{
    foo = {
        bar = 1;
        x = 2;
        # <----  new !
    };
}
```

--------------------------------

### Open Nix File for Code Actions

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs-bulk-multiline.md

Opens a Nix file containing attribute sets to enable code actions. The content defines multiple bindings within the 'foo' attribute.

```nix
{ 
  foo.bar = 1;
  foo.baz = 2;
  foo.qux = 3;
}
```

--------------------------------

### Inlay hints for package versions

Source: https://github.com/nix-community/nixd/blob/main/nixd/docs/features.md

Inlay hints display package versions directly in your system configuration, making it easier to track versions. The version strings are evaluated using the `name.version` attrpath and should align with your configured `nixpkgs`.

```nix
with pkgs;
[
    nix: 2.19.0
#       ~~~~~~~~~~~~~~ <-- the version, floating.
]
```

--------------------------------

### Open Nix File for Code Action

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/unused-def/multiple-bindings.md

Opens a Nix file with multiple bindings to demonstrate the unused binding removal code action. Ensure the file content is correctly provided.

```nix
let x = 1; y = 2; in y
```

--------------------------------

### Open Nix File for Code Action

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/add-to-formals/multiple-formals.md

Opens a Nix file with existing formals to trigger code actions. The file content is `{a, b, c}: d`.

```nix
{a, b, c}: d
```

--------------------------------

### Open Nix File and Request Hover

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/hover/options-in-config.md

Opens a Nix file containing a configuration and then requests hover information for a specific position within that file. This tests nixd's ability to provide details about Nix options.

```nix
{ config = { foo }; }
```

```json
{
   "jsonrpc": "2.0",
   "id": 2,
   "method": "textDocument/hover",
   "params":{
      "textDocument":{
         "uri": "file:///test.nix"
      },
      "position":{
         "line": 0,
         "character": 15
      }
   }
}
```

--------------------------------

### Open Nix File for Code Action

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/add-to-formals/basic.md

Opens a Nix file with a simple function definition to test the 'add to formals' code action. The file content is `{x}: y`.

```nix
{x}: y
```

--------------------------------

### Open Nix File with JSON Array

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/json-to-nix/json-to-nix-array.md

Simulates opening a Nix file containing a JSON array. This sets up the context for the code action.

```nix
[1, 2, 3]
```

--------------------------------

### Open Nix File for Testing

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/rewrite-string/not-string.md

Opens a Nix file named 'not-string.nix' for the language server to process.

```nix
{ x = 42; y = ./path; z = true; }
```

--------------------------------

### DidOpen Nix File

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/hover/2.md

Opens a basic Nix file named 'basic.nix' with the content '{ a = 1; }'. This prepares the language server for subsequent requests on this file.

```nix
{ a  = 1; }
```

--------------------------------

### Initialize Request

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/completion/comment.md

Sends an initialize request to the nixd server. This is typically the first message exchanged.

```json
{
   "jsonrpc":"2.0",
   "id":0,
   "method":"initialize",
   "params":{
      "processId":123,
      "rootPath":"",
      "capabilities": {
      },
      "trace":"off"
   }
}
```

--------------------------------

### Verify Definition Result for Package Selection

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/definition/select-package.md

This section uses FileCheck to verify that the definition provider correctly returns the URI and range for the selected package.

```text
CHECK: "id": 2,
CHECK-NEXT: "jsonrpc": "2.0",
CHECK-NEXT: "result": {
CHECK-NEXT:     "range": {
CHECK-NEXT:       "end": {
CHECK-NEXT:         "character": 0,
CHECK-NEXT:         "line": 33
CHECK-NEXT:       },
CHECK-NEXT:       "start": {
CHECK-NEXT:         "character": 0,
CHECK-NEXT:         "line": 33
CHECK-NEXT:       }
CHECK-NEXT:     },
CHECK-NEXT:     "uri": "file:///foo"
CHECK-NEXT:   }
```

--------------------------------

### Open Nix File for Analysis

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/with-to-let/with-to-let-shadowing.md

Opens a Nix file to enable analysis and code action suggestions.

```nix
with lib;
let foo = 1;
in foo + optionalString true "x"
```

--------------------------------

### Open Nix File for Code Actions

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs-bulk-non-contiguous.md

Opens a Nix file to enable code analysis and action suggestions.

```nix
{ foo.a = 1; bar = 2; foo.b = 3; }
```

--------------------------------

### Open Nix File

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs-sibling-different-prefix.md

Opens a Nix file for the language server to process. This file contains multiple dotted path bindings.

```nix
{ foo.bar = 1; baz.qux = 2; }
```

--------------------------------

### Open Nix File for Code Action

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/convert-to-inherit/convert-to-inherit-from-nested.md

Opens a Nix file containing a nested attribute set access. This prepares the file for code analysis and action requests.

```nix
{ x = lib.nested.x; }
```

--------------------------------

### Open Nix File for Code Action Test

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/convert-to-inherit/convert-to-inherit-with-default.md

Opens a Nix file named 'convert-to-inherit-with-default.nix' for analysis. The content includes a simple attribute set with a default value.

```nix
{ foo = lib.foo or null; }
```

--------------------------------

### Open Nix File for Code Action Test

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/with-to-let/with-to-let-cursor-not-on-with.md

Opens a Nix file containing a 'with' statement. This sets up the context for testing code actions.

```nix
with lib; optionalString foo "yes"
```

--------------------------------

### Open Nix File for Analysis

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/extract-to-file/extract-with-scope-vars.md

Opens a Nix file to enable code analysis and actions.

```nix
{ pkgs }: with pkgs; { buildInputs = [ foo bar ]; }
```

--------------------------------

### Nixd Hover Response with Documentation

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/hover/value-docs.md

The expected response from the nixd language server when hovering over 'myFunc'. It includes the documentation string defined in the Nix code.

```text
     CHECK: "id": 2, 
CHECK-NEXT: "jsonrpc": "2.0",
CHECK-NEXT:   "result": { 
CHECK-NEXT:     "contents": { 
CHECK-NEXT:       "kind": "markdown", 
CHECK-NEXT:       "value": "Documentation for myFunc 


" 
CHECK-NEXT:     }, 
CHECK-NEXT:     "range": { 
CHECK-NEXT:       "end": { 
CHECK-NEXT:         "character": 11, 
CHECK-NEXT:         "line": 0 
CHECK-NEXT:       }, 
CHECK-NEXT:       "start": { 
CHECK-NEXT:         "character": 0, 
CHECK-NEXT:         "line": 0 
CHECK-NEXT:       } 
CHECK-NEXT:     } 
CHECK-NEXT:   } 

```

--------------------------------

### Open Nix File for Analysis

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/unused-def/all-unused.md

Opens a Nix file in the LSP client to enable analysis. The file content is provided for the server to process.

```nix
let x = 1; y = 2; in 3
```

--------------------------------

### Open Completion Test File

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/completion/options-mid.md

Opens a Nix file for completion testing. This snippet demonstrates the content of the file being analyzed.

```nix
{ bar = 1; fo. bar = 1; }
```

--------------------------------

### Request Definition for Package Selection

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/definition/select-package.md

This JSON-RPC request asks the nixd language server for the definition of the selected package at a specific position in the Nix file.

```json
{
   "jsonrpc":"2.0",
   "id":2,
   "method":"textDocument/definition",
   "params":{
      "textDocument":{
         "uri":"file:///basic.nix"
      },
      "position":{
        "line": 0,
        "character":5
      }
   }
}
```

--------------------------------

### Open Nix File for Conversion

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/convert-to-inherit/convert-to-inherit-simple.md

Opens the Nix file containing the expression to be refactored. The content `{ foo = foo; }` is provided.

```nix
{ foo = foo; }
```

--------------------------------

### Open Nix File for Completion

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/completion/option-stop.md

Opens a Nix file containing an incomplete option definition to trigger completion. The file content is provided to the language server.

```nix
{ bar = 1; foo.bar. }
```

--------------------------------

### Open Nix File for Code Action

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/pack-attrs/pack-attrs.md

Opens a Nix file in the nixd language server to enable code analysis and action suggestions. The file content is provided directly.

```nix
{ foo.bar = 1; }
```

--------------------------------

### Open Nix File for Code Action

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/flatten-attrs/flatten-attrs-multi.md

Opens a Nix file to enable code analysis and actions. The content defines a nested attribute set.

```nix
{ foo = { bar = 1; baz = 2; }; }
```

--------------------------------

### Open Nix File for Code Action

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/convert-to-inherit/convert-to-inherit-rec.md

Opens a Nix file containing a recursive attribute set for analysis.

```nix
rec {
  foo = foo;
}
```

--------------------------------

### Open Nix File for Completion

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/completion/options-attrs-of-submodule-body.md

Opens a Nix file to enable code completion. The file defines a structure where completion is expected within a submodule.

```nix
{ 
  foo.bar.x = { 
    
  };
}
```

--------------------------------

### Open Empty Nix File

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/json-to-nix/json-to-nix-empty-array.md

Simulates opening an empty Nix file containing only an empty JSON array. This sets up the scenario for testing code actions.

```nix
[]
```

--------------------------------

### Open Nix File for Analysis

Source: https://github.com/nix-community/nixd/blob/main/nixd/tools/nixd/test/code-action/noogle-doc/noogle-lib-simple.md

Opens a Nix file with the language server to enable analysis. This allows subsequent code actions to be performed on the file's content.

```nix
lib.optionalString
```