fix test file detection

lua/test-samurai-jest-runner/init.lua

@@ -38,6 +38,47 @@ local function find_root(path, markers)
   return vim.fs.dirname(found[1])
 end
 
+local function find_nearest_package_root(path)
+  if not path or path == "" then
+    return nil
+  end
+  local dir = vim.fs.dirname(path)
+  local prev = nil
+  while dir and dir ~= prev do
+    local candidate = dir .. "/package.json"
+    if vim.fn.filereadable(candidate) == 1 then
+      return dir
+    end
+    prev = dir
+    dir = vim.fs.dirname(dir)
+  end
+  return nil
+end
+
+local function read_package_json(root)
+  if not root then
+    return nil
+  end
+  local ok, lines = pcall(vim.fn.readfile, root .. "/package.json")
+  if not ok then
+    return nil
+  end
+  local ok_decode, data = pcall(vim.json.decode, table.concat(lines, "\n"))
+  if not ok_decode then
+    return nil
+  end
+  return data
+end
+
+local function has_jest_dependency(pkg)
+  if not pkg or type(pkg) ~= "table" then
+    return false
+  end
+  local deps = pkg.dependencies or {}
+  local dev_deps = pkg.devDependencies or {}
+  return deps.jest ~= nil or dev_deps.jest ~= nil
+end
+
 local function count_char(line, ch)
   local count = 0
   for i = 1, #line do
@@ -346,7 +387,12 @@ end
 
 function runner.is_test_file(bufnr)
   local path = get_buf_path(bufnr)
-  return test_file_path(path)
+  if not test_file_path(path) then
+    return false
+  end
+  local root = find_nearest_package_root(path)
+  local pkg = read_package_json(root)
+  return has_jest_dependency(pkg)
 end
 
 function runner.find_nearest(bufnr, row, _col)
@@ -354,7 +400,7 @@ function runner.find_nearest(bufnr, row, _col)
   if not path or path == "" then
     return nil, "no file name"
   end
-  if not test_file_path(path) then
+  if not runner.is_test_file(bufnr) then
     return nil, "not a jest test file"
   end
   local lines = get_buf_lines(bufnr)