JSON内の特定の値をマスクする

目的

APIリクエスト・レスポンスをログに吐きだす際など用のメモ書き

例

javascript

const MASK_KEYS = ['email', 'password']

const maskJson = obj =>
  MASK_KEYS.reduce(
    (memo, key) =>
      memo.replace(new RegExp(`"${key}":"[^,}]*"`), `"${key}":"XXXXXX"`),
    JSON.stringify(obj)
  )

console

maskJson({ email: '[e-mail]', password: 'password' })
=> "{"email":"XXXXXX","password":"XXXXXX"}"

ruby

MASK_KEYS = %w[email password].freeze

def mask_json(hash)
  MASK_KEYS.inject(JSON.generate(hash)) { |memo, key| memo.gsub(/("#{key}":"[^,}]*")/, "\"#{key}\":\"XXXXXX\"") }
end

console

mask_json({ email: '[e-mail]', password: 'password' })
=> "{\"email\":\"XXXXXX\",\"password\":\"XXXXXX\"}"