fix(heartbeat): add language fallback detection from file extension

lua/shelltime/heartbeat.lua

@@ -3,6 +3,7 @@
 local config = require('shelltime.config')
 local system = require('shelltime.utils.system')
 local git = require('shelltime.utils.git')
+local lang = require('shelltime.utils.language')
 
 local M = {}
 
@@ -103,7 +104,7 @@ local function create_heartbeat(bufnr, is_write)
     project = system.get_project_name(project_root),
     projectRootPath = project_root,
     branch = git.get_branch(file_path),
-    language = vim.bo[bufnr].filetype or '',
+    language = lang.get_language(vim.bo[bufnr].filetype, file_path),
     lines = vim.api.nvim_buf_line_count(bufnr),
     lineNumber = cursor[1],       -- Already 1-indexed
     cursorPosition = cursor[2],   -- 0-indexed column

lua/shelltime/utils/init.lua

@@ -5,5 +5,6 @@ local M = {}
 M.system = require('shelltime.utils.system')
 M.git = require('shelltime.utils.git')
 M.yaml = require('shelltime.utils.yaml')
+M.language = require('shelltime.utils.language')
 
 return M

lua/shelltime/utils/language.lua

@@ -0,0 +1,85 @@
+-- Language detection utilities for shelltime
+-- Provides fallback language detection from file extension when filetype is empty
+
+local M = {}
+
+-- File extension to language mapping (used only when filetype is empty)
+local extension_map = {
+  lua = 'lua',
+  py = 'python',
+  js = 'javascript',
+  ts = 'typescript',
+  tsx = 'typescriptreact',
+  jsx = 'javascriptreact',
+  rs = 'rust',
+  go = 'go',
+  rb = 'ruby',
+  php = 'php',
+  java = 'java',
+  kt = 'kotlin',
+  swift = 'swift',
+  c = 'c',
+  cpp = 'cpp',
+  cc = 'cpp',
+  cxx = 'cpp',
+  h = 'c',
+  hpp = 'cpp',
+  cs = 'csharp',
+  sh = 'sh',
+  bash = 'bash',
+  zsh = 'zsh',
+  fish = 'fish',
+  html = 'html',
+  css = 'css',
+  scss = 'scss',
+  less = 'less',
+  json = 'json',
+  yaml = 'yaml',
+  yml = 'yaml',
+  xml = 'xml',
+  md = 'markdown',
+  sql = 'sql',
+  vim = 'vim',
+  dockerfile = 'dockerfile',
+  toml = 'toml',
+  ini = 'ini',
+  conf = 'conf',
+}
+
+--- Get language for a file
+---@param filetype string|nil Buffer filetype
+---@param file_path string File path
+---@return string Language identifier
+function M.get_language(filetype, file_path)
+  -- Use filetype if available
+  if filetype and filetype ~= '' then
+    return filetype
+  end
+
+  -- Fallback: detect from file extension
+  local filename = file_path:match('[/\\]?([^/\\]+)$') or ''
+
+  -- Check for hidden files without extension (e.g., .hidden, .gitignore)
+  -- These start with a dot and have no other dots
+  if filename:match('^%.[^%.]+$') then
+    return ''
+  end
+
+  local ext = file_path:match('%.([^%.]+)$')
+  if ext then
+    ext = ext:lower()
+    return extension_map[ext] or ext
+  end
+
+  -- Special case: Dockerfile, Makefile, etc.
+  local basename = filename:lower()
+  if basename == 'dockerfile' then
+    return 'dockerfile'
+  elseif basename == 'makefile' then
+    return 'makefile'
+  end
+
+  return ''
+end
+
+return M

tests/helpers/reset.lua

@@ -20,6 +20,7 @@ function M.reset_all()
     'shelltime.utils.system',
     'shelltime.utils.git',
     'shelltime.utils.yaml',
+    'shelltime.utils.language',
   }
   for _, name in ipairs(modules) do
     package.loaded[name] = nil

tests/language_spec.lua

@@ -0,0 +1,163 @@
+-- Tests for shelltime/utils/language.lua
+describe('shelltime.utils.language', function()
+  local language
+
+  before_each(function()
+    package.loaded['shelltime.utils.language'] = nil
+    language = require('shelltime.utils.language')
+  end)
+
+  describe('get_language', function()
+    describe('when filetype is available', function()
+      it('should return filetype as-is for lua', function()
+        assert.equals('lua', language.get_language('lua', '/path/to/file.lua'))
+      end)
+
+      it('should return filetype as-is for python', function()
+        assert.equals('python', language.get_language('python', '/path/to/file.py'))
+      end)
+
+      it('should return filetype as-is for typescript', function()
+        assert.equals('typescript', language.get_language('typescript', '/path/to/file.ts'))
+      end)
+
+      it('should return filetype as-is for javascript', function()
+        assert.equals('javascript', language.get_language('javascript', '/path/to/file.js'))
+      end)
+
+      it('should return filetype as-is for sh', function()
+        assert.equals('sh', language.get_language('sh', '/path/to/file.sh'))
+      end)
+
+      it('should return filetype as-is for vim', function()
+        assert.equals('vim', language.get_language('vim', '/path/to/file.vim'))
+      end)
+
+      it('should return filetype even if extension differs', function()
+        assert.equals('python', language.get_language('python', '/path/to/file.txt'))
+      end)
+    end)
+
+    describe('when filetype is empty', function()
+      it('should detect lua from extension', function()
+        assert.equals('lua', language.get_language('', '/path/to/file.lua'))
+      end)
+
+      it('should detect python from .py extension', function()
+        assert.equals('python', language.get_language('', '/path/to/file.py'))
+      end)
+
+      it('should detect javascript from .js extension', function()
+        assert.equals('javascript', language.get_language('', '/path/to/file.js'))
+      end)
+
+      it('should detect typescript from .ts extension', function()
+        assert.equals('typescript', language.get_language('', '/path/to/file.ts'))
+      end)
+
+      it('should detect typescriptreact from .tsx extension', function()
+        assert.equals('typescriptreact', language.get_language('', '/path/to/file.tsx'))
+      end)
+
+      it('should detect javascriptreact from .jsx extension', function()
+        assert.equals('javascriptreact', language.get_language('', '/path/to/file.jsx'))
+      end)
+
+      it('should detect rust from .rs extension', function()
+        assert.equals('rust', language.get_language('', '/path/to/file.rs'))
+      end)
+
+      it('should detect go from .go extension', function()
+        assert.equals('go', language.get_language('', '/path/to/file.go'))
+      end)
+
+      it('should detect csharp from .cs extension', function()
+        assert.equals('csharp', language.get_language('', '/path/to/file.cs'))
+      end)
+
+      it('should detect cpp from .cpp extension', function()
+        assert.equals('cpp', language.get_language('', '/path/to/file.cpp'))
+      end)
+
+      it('should detect cpp from .cc extension', function()
+        assert.equals('cpp', language.get_language('', '/path/to/file.cc'))
+      end)
+
+      it('should detect yaml from .yaml extension', function()
+        assert.equals('yaml', language.get_language('', '/path/to/file.yaml'))
+      end)
+
+      it('should detect yaml from .yml extension', function()
+        assert.equals('yaml', language.get_language('', '/path/to/file.yml'))
+      end)
+
+      it('should detect markdown from .md extension', function()
+        assert.equals('markdown', language.get_language('', '/path/to/file.md'))
+      end)
+
+      it('should detect json from .json extension', function()
+        assert.equals('json', language.get_language('', '/path/to/file.json'))
+      end)
+
+      it('should handle uppercase extensions', function()
+        assert.equals('lua', language.get_language('', '/path/to/file.LUA'))
+      end)
+
+      it('should handle mixed case extensions', function()
+        assert.equals('python', language.get_language('', '/path/to/file.Py'))
+      end)
+
+      it('should return unknown extension as-is', function()
+        assert.equals('xyz', language.get_language('', '/path/to/file.xyz'))
+      end)
+    end)
+
+    describe('special filenames', function()
+      it('should detect dockerfile', function()
+        assert.equals('dockerfile', language.get_language('', '/path/to/Dockerfile'))
+      end)
+
+      it('should detect dockerfile case insensitive', function()
+        assert.equals('dockerfile', language.get_language('', '/path/to/dockerfile'))
+      end)
+
+      it('should detect makefile', function()
+        assert.equals('makefile', language.get_language('', '/path/to/Makefile'))
+      end)
+
+      it('should detect makefile case insensitive', function()
+        assert.equals('makefile', language.get_language('', '/path/to/makefile'))
+      end)
+    end)
+
+    describe('edge cases', function()
+      it('should return empty string for nil filetype and no extension', function()
+        assert.equals('', language.get_language(nil, '/path/to/file'))
+      end)
+
+      it('should return empty string for empty filetype and no extension', function()
+        assert.equals('', language.get_language('', '/path/to/file'))
+      end)
+
+      it('should handle file with multiple dots', function()
+        assert.equals('lua', language.get_language('', '/path/to/file.test.lua'))
+      end)
+
+      it('should handle hidden files with extension', function()
+        assert.equals('yaml', language.get_language('', '/path/to/.hidden.yaml'))
+      end)
+
+      it('should return empty for hidden files without extension', function()
+        assert.equals('', language.get_language('', '/path/to/.hidden'))
+      end)
+
+      it('should handle nil filetype', function()
+        assert.equals('lua', language.get_language(nil, '/path/to/file.lua'))
+      end)
+
+      it('should prefer filetype over extension', function()
+        assert.equals('typescriptreact', language.get_language('typescriptreact', '/path/to/file.tsx'))
+      end)
+    end)
+  end)
+end)