ci: nix

Problem: no nix dev shell existed, making it harder to get local
tooling for formatting, linting, and type checking.

Solution: add a flake with a devShell providing prettier, stylua,
selene, and lua-language-server.

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -0,0 +1,78 @@
+name: Bug Report
+description: Report a bug
+title: 'bug: '
+labels: [bug]
+body:
+  - type: checkboxes
+    attributes:
+      label: Prerequisites
+      options:
+        - label:
+            I have searched [existing
+            issues](https://github.com/barrettruth/midnight.nvim/issues)
+          required: true
+        - label: I have updated to the latest version
+          required: true
+
+  - type: textarea
+    attributes:
+      label: 'Neovim version'
+      description: 'Output of `nvim --version`'
+      render: text
+    validations:
+      required: true
+
+  - type: input
+    attributes:
+      label: 'Operating system'
+      placeholder: 'e.g. Arch Linux, macOS 15, Ubuntu 24.04'
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Description
+      description: What happened? What did you expect?
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Steps to reproduce
+      description: Minimal steps to trigger the bug
+      value: |
+        1.
+        2.
+        3.
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: 'Health check'
+      description: 'Output of `:checkhealth midnight`'
+      render: text
+
+  - type: textarea
+    attributes:
+      label: Minimal reproduction
+      description: |
+        Save the script below as `repro.lua`, edit if needed, and run:
+        ```
+        nvim -u repro.lua
+        ```
+        Confirm the bug reproduces with this config before submitting.
+      render: lua
+      value: |
+        vim.env.LAZY_STDPATH = '.repro'
+        load(vim.fn.system('curl -s https://raw.githubusercontent.com/folke/lazy.nvim/main/bootstrap.lua'))()
+        require('lazy.nvim').setup({
+          spec = {
+            {
+              'barrett-ruth/midnight.nvim',
+              opts = {},
+            },
+          },
+        })
+    validations:
+      required: true

.github/ISSUE_TEMPLATE/config.yaml

@@ -0,0 +1,5 @@
+blank_issues_enabled: false
+contact_links:
+  - name: Questions
+    url: https://github.com/barrettruth/midnight.nvim/discussions
+    about: Ask questions and discuss ideas

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -0,0 +1,30 @@
+name: Feature Request
+description: Suggest a feature
+title: 'feat: '
+labels: [enhancement]
+body:
+  - type: checkboxes
+    attributes:
+      label: Prerequisites
+      options:
+        - label:
+            I have searched [existing
+            issues](https://github.com/barrettruth/midnight.nvim/issues)
+          required: true
+
+  - type: textarea
+    attributes:
+      label: Problem
+      description: What problem does this solve?
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Proposed solution
+    validations:
+      required: true
+
+  - type: textarea
+    attributes:
+      label: Alternatives considered

.github/workflows/quality.yaml

@@ -11,7 +11,6 @@ jobs:
     runs-on: ubuntu-latest
     outputs:
       lua: ${{ steps.changes.outputs.lua }}
-      python: ${{ steps.changes.outputs.python }}
       markdown: ${{ steps.changes.outputs.markdown }}
     steps:
       - uses: actions/checkout@v4
@@ -25,10 +24,7 @@ jobs:
               - '*.lua'
               - '.luarc.json'
               - '*.toml'
-            python:
-              - 'scripts/**/*.py'
-              - 'pyproject.toml'
-              - 'uv.lock'
+              - 'vim.yaml'
             markdown:
               - '*.md'
 
@@ -39,11 +35,8 @@ jobs:
     if: ${{ needs.changes.outputs.lua == 'true' }}
     steps:
       - uses: actions/checkout@v4
-      - uses: JohnnyMorganz/stylua-action@v4
-        with:
-          token: ${{ secrets.GITHUB_TOKEN }}
-          version: 2.1.0
-          args: --check .
+      - uses: cachix/install-nix-action@v31
+      - run: nix develop --command stylua --check .
 
   lua-lint:
     name: Lua Lint Check
@@ -52,11 +45,8 @@ jobs:
     if: ${{ needs.changes.outputs.lua == 'true' }}
     steps:
       - uses: actions/checkout@v4
-      - name: Lint with Selene
-        uses: NTBBloodbath/selene-action@v1.0.0
-        with:
-          token: ${{ secrets.GITHUB_TOKEN }}
-          args: --display-style quiet .
+      - uses: cachix/install-nix-action@v31
+      - run: nix develop --command selene --display-style quiet .
 
   lua-typecheck:
     name: Lua Type Check
@@ -72,48 +62,6 @@ jobs:
           directories: lua
           configpath: .luarc.json
 
-  python-format:
-    name: Python Format Check
-    runs-on: ubuntu-latest
-    needs: changes
-    if: ${{ needs.changes.outputs.python == 'true' }}
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install uv
-        uses: astral-sh/setup-uv@v4
-      - name: Install ruff
-        run: uv tool install ruff
-      - name: Check Python formatting with ruff
-        run: ruff format --check .
-
-  python-lint:
-    name: Python Lint Check
-    runs-on: ubuntu-latest
-    needs: changes
-    if: ${{ needs.changes.outputs.python == 'true' }}
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install uv
-        uses: astral-sh/setup-uv@v4
-      - name: Install ruff
-        run: uv tool install ruff
-      - name: Lint Python files with ruff
-        run: ruff check .
-
-  python-typecheck:
-    name: Python Type Check
-    runs-on: ubuntu-latest
-    needs: changes
-    if: ${{ needs.changes.outputs.python == 'true' }}
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install uv
-        uses: astral-sh/setup-uv@v4
-      - name: Install dependencies with mypy
-        run: uv sync --dev
-      - name: Type check Python files with mypy
-        run: uv run mypy .
-
   markdown-format:
     name: Markdown Format Check
     runs-on: ubuntu-latest
@@ -121,15 +69,5 @@ jobs:
     if: ${{ needs.changes.outputs.markdown == 'true' }}
     steps:
       - uses: actions/checkout@v4
-      - name: Setup pnpm
-        uses: pnpm/action-setup@v4
-        with:
-          version: 8
-      - name: Setup Node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: '20'
-      - name: Install prettier
-        run: pnpm add -g prettier@3.1.0
-      - name: Check markdown formatting with prettier
-        run: prettier --check .
+      - uses: cachix/install-nix-action@v31
+      - run: nix develop --command prettier --check .

.gitignore

@@ -8,3 +8,6 @@ venv/
 CLAUDE.md
 __pycache__
 node_modules/
+
+.direnv/
+.envrc

.luarc.json

@@ -1,8 +1,9 @@
 {
-  "runtime.version": "Lua 5.1",
+  "runtime.version": "LuaJIT",
   "runtime.path": ["lua/?.lua", "lua/?/init.lua"],
   "diagnostics.globals": ["vim"],
   "workspace.library": ["$VIMRUNTIME/lua", "${3rd}/luv/library"],
   "workspace.checkThirdParty": false,
+  "workspace.ignoreDir": [".direnv"],
   "completion.callSnippet": "Replace"
 }

.pre-commit-config.yaml

@@ -9,26 +9,6 @@ repos:
         files: \.lua$
         pass_filenames: true
 
-  - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.14.3
-    hooks:
-      - id: ruff-format
-        name: ruff (format)
-        files: \.py$
-      - id: ruff
-        name: ruff (lint imports)
-        args: ['--fix', '--select=I']
-        files: \.py$
-
-  - repo: local
-    hooks:
-      - id: mypy
-        name: mypy (type check)
-        entry: uv run mypy
-        language: system
-        args: ['.']
-        pass_filenames: false
-
   - repo: https://github.com/pre-commit/mirrors-prettier
     rev: v4.0.0-alpha.8
     hooks:

.styluaignore

@@ -0,0 +1 @@
+.direnv/

README.md

@@ -1,24 +1,25 @@
 # midnight.nvim
 
-neovim theme for code, not colors.
+Neovim theme for code, not colors.
 
 ![Image](https://github.com/user-attachments/assets/9abb5126-15d7-4de4-ad6d-ec35975fec03)
 
 ## Installation
 
-Install with any package manager of your choice. For example, with
-[lazy.nvim](https://github.com/folke/lazy.nvim):
+Install using your package manager of choice or via
+[luarocks](https://luarocks.org/modules/barrettruth/midnight.nvim):
 
-```lua
-{
-  'barrett-ruth/midnight.nvim',
-  config = function()
-    vim.cmd.colorscheme('midnight')
-  end,
-}
+```
+luarocks install midnight.nvim
 ```
 
-## Plugin Integration
+Then set the colorscheme:
+
+```lua
+vim.cmd.colorscheme('midnight')
+```
+
+## Plugin Integrations
 
 - [treesitter](https://github.com/nvim-treesitter/nvim-treesitter)
 - [fzf-lua](https://github.com/ibhagwan/fzf-lua)
@@ -29,7 +30,7 @@ Install with any package manager of your choice. For example, with
 ## Motivation
 
 I find existing colorschemes to generally be excessively colorful and
-distracting, rather than informative. I wrote midnight.nvim to focus on code
+distracting rather than informative. I wrote midnight.nvim to focus on code
 structure, specifically for competitive programming and workplace software
 development environments. I included highlighting of constants (e.g. strings,
 numbers, booleans) and language keywords to emphasize the maximally important

colors/daylight.lua

@@ -1,2 +1 @@
-vim.o.background = 'light'
 require('midnight').load()

colors/midnight.lua

@@ -1,2 +1 @@
-vim.o.background = 'dark'
 require('midnight').load()

doc/midnight.nvim.txt

@@ -16,7 +16,7 @@ INSTALLATION                                           *midnight-installation*
 
 >lua
     {
-      'barrett-ruth/midnight.nvim',
+      'barrettruth/midnight.nvim',
       config = function()
         vim.cmd.colorscheme('midnight')
       end,

flake.lock

@@ -0,0 +1,43 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1771423170,
+        "narHash": "sha256-K7Dg9TQ0mOcAtWTO/FX/FaprtWQ8BmEXTpLIaNRhEwU=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "bcc4a9d9533c033d806a46b37dc444f9b0da49dd",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs",
+        "systems": "systems"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,33 @@
+{
+  description = "midnight.nvim — a dark colorscheme for Neovim";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    systems.url = "github:nix-systems/default";
+  };
+
+  outputs =
+    {
+      nixpkgs,
+      systems,
+      ...
+    }:
+    let
+      forEachSystem =
+        f: nixpkgs.lib.genAttrs (import systems) (system: f nixpkgs.legacyPackages.${system});
+    in
+    {
+      formatter = forEachSystem (pkgs: pkgs.nixfmt-tree);
+
+      devShells = forEachSystem (pkgs: {
+        default = pkgs.mkShell {
+          packages = [
+            pkgs.prettier
+            pkgs.stylua
+            pkgs.selene
+            pkgs.lua-language-server
+          ];
+        };
+      });
+    };
+}

lua/midnight/init.lua

@@ -1,16 +1,14 @@
 local M = {}
 
----@class MidnightConfig
----@field [string] any
-
----@param opts? MidnightConfig
----@return nil
-function M.setup(opts)
-  opts = opts or {}
-end
+local loading = false
 
 ---@return nil
 function M.load()
+  if loading then
+    return
+  end
+  loading = true
+
   if vim.g.colors_name then
     vim.cmd('hi clear')
   end
@@ -24,6 +22,21 @@ function M.load()
 
   local theme = require('midnight.theme')
   theme.apply()
+
+  loading = false
+end
+
+---@deprecated Use `vim.cmd('colorscheme midnight')` instead
+function M.setup(_opts)
+  vim.deprecate(
+    'require("midnight").setup()',
+    'vim.cmd("colorscheme midnight")',
+    'v0.1.0',
+    'midnight.nvim',
+    false
+  )
+
+  M.load()
 end
 
 return M

lua/midnight/palette.lua

@@ -1,5 +1,22 @@
 local M = {}
 
+---@param hex string
+---@param bg_hex string
+---@param alpha number
+---@return string
+function M.blend(hex, bg_hex, alpha)
+  local function parse(h)
+    h = h:gsub('#', '')
+    return tonumber(h:sub(1, 2), 16), tonumber(h:sub(3, 4), 16), tonumber(h:sub(5, 6), 16)
+  end
+  local r, g, b = parse(hex)
+  local bg_r, bg_g, bg_b = parse(bg_hex)
+  local blend_r = math.floor(r * alpha + bg_r * (1 - alpha))
+  local blend_g = math.floor(g * alpha + bg_g * (1 - alpha))
+  local blend_b = math.floor(b * alpha + bg_b * (1 - alpha))
+  return string.format('#%02x%02x%02x', blend_r, blend_g, blend_b)
+end
+
 ---@class Palette
 ---@field foreground string
 ---@field red string
@@ -31,6 +48,9 @@ local M = {}
 ---@field light_cyan? string
 ---@field light_white? string
 ---@field medium_emphasis? string
+---@field diff_add? string
+---@field diff_delete? string
+---@field diff_change? string
 
 ---@type Palette
 M.midnight = {
@@ -59,6 +79,15 @@ M.midnight = {
   dark_grey = '#222222',
 
   medium_emphasis = '#999999',
+
+  -- Diff backgrounds: base color blended at 40% with visual bg (#121212)
+  -- Generated via: M.blend(base_color, '#121212', 0.4)
+  -- diff_add = M.blend('#98c379', '#121212', 0.4)    -- green
+  -- diff_delete = M.blend('#ff6b6b', '#121212', 0.4) -- red
+  -- diff_change = M.blend('#7aa2f7', '#121212', 0.4) -- blue
+  diff_add = '#0c2f1e',
+  diff_delete = '#291f27',
+  diff_change = '#3a4a6d',
 }
 
 ---@type Palette
@@ -88,6 +117,12 @@ M.daylight = {
   dark_grey = '#ebebeb',
 
   medium_emphasis = '#666666',
+
+  -- Diff backgrounds: base color blended at 40% with visual bg (#f5f5f5)
+  -- Generated via: M.blend(base_color, '#f5f5f5', 0.4)
+  diff_add = '#a5c5ab',
+  diff_delete = '#e2a1b2',
+  diff_change = '#a9b7e5',
 }
 
 ---@return Palette

lua/midnight/theme.lua

@@ -65,7 +65,7 @@ function M.apply()
   hi('NonText', { fg = cs.grey }, { 'SpecialKey' })
 
   hi('LineNr', { fg = cs.light_black }, { 'SignColumn' })
-  hi('CursorLine', { bg = cs.dark_grey }, { 'ColorColumn', 'Folded', 'Visual' })
+  hi('CursorLine', { bg = cs.dark_grey, underline = false }, { 'ColorColumn', 'Folded', 'Visual' })
   hi('CursorLineNr', { fg = cs.medium_emphasis })
 
   hi('Conceal', { fg = cs.light_black, bg = cs.foreground })
@@ -121,9 +121,13 @@ function M.apply()
 
   hi('@variable', { none = true })
 
-  hi('Pmenu', { bg = cs.dark_grey }, { 'PmenuSbar' })
+  hi('Pmenu', { fg = cs.background, bg = cs.foreground }, { 'PmenuSbar' })
   hi('PmenuSel', { bg = cs.med_grey })
   hi('PmenuThumb', { bg = cs.grey })
+  hi('BlinkCmpMenu', { fg = cs.background, bg = cs.foreground })
+  hi('BlinkCmpMenuBorder', { fg = cs.background, bg = cs.foreground })
+  hi('BlinkCmpDoc', { fg = cs.background, bg = cs.foreground })
+  hi('BlinkCmpDocBorder', { fg = cs.background, bg = cs.foreground })
 
   hi('LspInlayHint', { fg = cs.light_black })
   hi('LspSignatureActiveParameter', { underline = true, italic = true })
@@ -145,18 +149,32 @@ function M.apply()
 
   hi('gitCommitSummary', { fg = cs.background })
 
-  hi('@attribute.diff', { fg = cs.background })
-  hi('DiffAdd', { fg = cs.green }, { '@text.diff.add', 'diffAdded' })
-  hi('DiffDelete', { fg = cs.red }, { '@text.diff.delete', 'diffRemoved' })
-  hi('DiffChange', { fg = cs.yellow })
+  hi('@attribute.diff', { fg = cs.blue })
+  hi('@diff.minus', { fg = cs.red })
+  hi('@diff.plus', { fg = cs.green })
+  hi('@diff.delta', { fg = cs.blue })
+  hi('@punctuation.special.diff', { fg = cs.blue })
+
+  link('Normal', { '@string.special.path', '@variable.parameter' })
+  hi('DiffAdd', { bg = cs.diff_add, fg = cs.green }, { '@text.diff.add', 'diffAdded' })
+  hi('DiffDelete', { bg = cs.diff_delete, fg = cs.red }, { '@text.diff.delete', 'diffRemoved' })
+  hi('DiffChange', { bg = cs.diff_change, fg = cs.blue })
+  hi('DiffText', { bg = cs.blue, fg = cs.foreground })
+
+  hi('DiffsDiffAdd', { bg = cs.diff_add })
+  hi('DiffsDiffDelete', { bg = cs.diff_delete })
+  hi('DiffsDiffChange', { bg = cs.diff_change })
+  hi('DiffsDiffText', { bg = cs.blue })
 
   hi('@constructor.lua', { fg = cs.background })
   hi('@markup.heading.gitcommit', { none = true })
 
+  hi('@function.latex', { fg = cs.blue })
+
   hi('GitSignsCurrentLineBlame', { italic = true, fg = cs.light_black })
-  link('DiffAdd', 'GitSignsAdd')
-  link('DiffChange', 'GitSignsChange')
-  link('DiffDelete', 'GitSignsDelete')
+  hi('GitSignsAdd', { fg = cs.green })
+  hi('GitSignsChange', { fg = cs.blue })
+  hi('GitSignsDelete', { fg = cs.red })
 
   link('Search', 'HighlightUndo')
 
@@ -165,6 +183,23 @@ function M.apply()
   hi('CmpItemAbbr', { fg = cs.background })
   hi('CmpItemAbbrMatch', { fg = cs.background, bold = true })
   hi('CmpItemAbbrMatchFuzzy', { fg = cs.background, bold = true })
+  hi('BlinkCmpLabelMatch', { fg = cs.green })
+  hi('BlinkCmpGhostText', { fg = cs.light_black })
+  hi('BlinkCmpGitKindMR', { fg = cs.magenta })
+  hi('BlinkCmpGitKindPR', { fg = cs.magenta })
+  hi('BlinkCmpGitKindIssue', { fg = cs.magenta })
+  hi('BlinkCmpGitKindCommit', { fg = cs.magenta })
+  hi('BlinkCmpGitKindMention', { fg = cs.magenta })
+  hi('BlinkCmpGitKindIconMR', { fg = cs.magenta })
+  hi('BlinkCmpGitKindIconPR', { fg = cs.magenta })
+  hi('BlinkCmpGitKindIconIssue', { fg = cs.magenta })
+  hi('BlinkCmpGitKindIconCommit', { fg = cs.magenta })
+  hi('BlinkCmpGitKindIconMention', { fg = cs.magenta })
+  hi('BlinkCmpGitLabelMRId', { fg = cs.magenta })
+  hi('BlinkCmpGitLabelPRId', { fg = cs.magenta })
+  hi('BlinkCmpGitLabelIssueId', { fg = cs.magenta })
+  hi('BlinkCmpGitLabelCommitId', { fg = cs.magenta })
+  hi('BlinkCmpGitLabelMentionId', { fg = cs.magenta })
   hi('CmpItemAbbrDeprecated', { fg = cs.light_black, strikethrough = true })
   hi('CmpItemMenu', { fg = cs.light_black })
 

midnight.nvim-scm-1.rockspec

@@ -2,5 +2,5 @@ rockspec_format = '3.0'
 package = 'midnight.nvim'
 version = 'scm-1'
 
-source = { url = 'git://github.com/barrett-ruth/midnight.nvim' }
+source = { url = 'git://github.com/barrettruth/midnight.nvim' }
 build = { type = 'builtin' }

scripts/ci.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+set -eu
+
+nix develop --command stylua --check .
+git ls-files '*.lua' | xargs nix develop --command selene --display-style quiet
+nix develop --command prettier --check .
+nix fmt
+git diff --exit-code -- '*.nix'
+nix develop --command lua-language-server --check . --checklevel=Warning

selene.toml

@@ -1 +1,4 @@
 std = 'vim'
+
+[lints]
+bad_string_escape = 'allow'

vim.toml

@@ -1,30 +0,0 @@
-[selene]
-base = "lua51"
-name = "vim"
-
-[vim]
-any = true
-
-[jit]
-any = true
-
-[assert]
-any = true
-
-[describe]
-any = true
-
-[it]
-any = true
-
-[before_each]
-any = true
-
-[after_each]
-any = true
-
-[spy]
-any = true
-
-[stub]
-any = true

vim.yaml

@@ -0,0 +1,26 @@
+---
+base: lua51
+name: vim
+lua_versions:
+  - luajit
+globals:
+  vim:
+    any: true
+  jit:
+    any: true
+  assert:
+    any: true
+  describe:
+    any: true
+  it:
+    any: true
+  before_each:
+    any: true
+  after_each:
+    any: true
+  spy:
+    any: true
+  stub:
+    any: true
+  bit:
+    any: true