{"id":2121,"date":"2017-01-20T02:00:00","date_gmt":"2017-01-20T02:00:00","guid":{"rendered":"https:\/\/www.microsoft.com\/reallifecode\/index.php\/2017\/01\/20\/unit-testing-for-bot-applications\/"},"modified":"2020-03-15T05:55:28","modified_gmt":"2020-03-15T12:55:28","slug":"unit-testing-for-bot-applications","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/ise\/unit-testing-for-bot-applications\/","title":{"rendered":"Unit Testing for Bot Applications"},"content":{"rendered":"

Image: Mr Robot has some RAM<\/a> by Chris Isherwood<\/a>, used by CC BY 2.0<\/a><\/em><\/p>\n

First Things First<\/h2>\n

Writing code using ad-hoc technologies like Microsoft Bot Framework<\/a> (MBF) is fun and exciting.\nBut before rushing to code bots that can make coffee and send spaceships to the moon, you need to think about unit testing your code.<\/p>\n

Recently, we worked with Moed.ai<\/a> on a bot that schedules tasks and manages resources\u2019 time slots.\nIn order to ensure the quality of their bot Moed.ai<\/strong> wanted the ability to unit-test their bot logic.<\/p>\n

This code story outlines the way we tackled the challenge of adding unit test support in Microsoft Bot Framework.<\/p>\n

What Should We Test?<\/h3>\n

The first question we tried answering was \u201cWhat are we trying to test?\u201d<\/p>\n

Bots built using MBF dialogs<\/a> and intents<\/a> usually consist of code intertwined with framework code.\nMoreover, major parts of the framework require external connectivity for saving session states or querying LUIS<\/a> models.<\/p>\n

In most projects, when we think about unit testing, we think about segregated sections of logic that receive input and are expected to return specific output.\nIn case this logic has external dependencies, we need to search for ways to abstract those dependencies and provide stubs during testing.<\/p>\n

This means we can take one of the following approaches:<\/p>\n

    \n
  1. Move the project\u2019s code to a separate module or directory and remove any dependencies on MBF<\/li>\n
  2. Find a way to test the conversational logic of the bot without external dependencies<\/li>\n<\/ol>\n

    Code Separation Difficulty<\/h3>\n

    Writing code for bots is a little different than writing code for other web-based applications.<\/p>\n

    Writing code for bot applications looks a lot like describing the way a conversational flow may evolve.\nFor example, just like in a customer service conversation, the bot application waits for a request that it can understand from the user to start a meaningful conversation. Then, during a series of questions and answers, it collects more data while trying to understand and provide the user with the best service.\nTaking maintainability and readability into account, it is important that such conversations represented by your code are understandable.<\/p>\n

    Moreover, in bot scenarios, many actions and decisions require a high level of dependency on MBF.<\/p>\n

    Here are some examples of code that are dependent on MBF:<\/p>\n

    \n
    \/\/ Prompting the user for input<\/span>\r\nbuilder<\/span>.<\/span>Prompts<\/span>.<\/span>choice<\/span>(<\/span>session<\/span>,<\/span> 'What would you like to do?'<\/span>,<\/span> [<\/span> \"Play Games\"<\/span>,<\/span> \"Do serious work\"<\/span>,<\/span> \"Other\"<\/span> ]);<\/span>\r\n\r\n\/\/ Saving data in session variable<\/span>\r\nsession<\/span>.<\/span>conversationData<\/span>.<\/span>userChoice<\/span> =<\/span> \"Play games while appearing to work seriously\"<\/span>;<\/span>\r\n\r\n\/\/ Beginning new dialogs or sending a \"typing\" status<\/span>\r\nsession<\/span>.<\/span>send<\/span>(<\/span>\"Give a raise to smart worker\"<\/span>);<\/span>\r\nsession<\/span>.<\/span>sendTyping<\/span>();<\/span>\r\n\r\n\/\/ Ending a conversation<\/span>\r\nsession<\/span>.<\/span>endDialog<\/span>(<\/span>\"Good Bye\"<\/span>);<\/span>\r\n<\/code><\/pre>\n<\/div>\n
    A conversational flow consists of multiple REST calls and replies between the user and the web server. Trying to separate our logic from the conversational flow in many cases left us with almost no code to test. Moreover, that separation left the conversational flow logic untested.<\/p>\n
    When we thought about unit testing in the world of bots, we realized that conversational flow logic is intertwined with the core logic of our application. This realization led us to develop a unique approach to testing the bot.<\/p>\n
    How Do We Test Conversational Flow Logic?<\/h2>\n
    For the purpose of this case study, we create a sample Alarm Clock Bot<\/strong>. A working copy of this bot application is available in this GitHub repo<\/a>.<\/p>\n
    Let\u2019s look at the following breakdown of a request to the bot application:<\/p>\n