Automate with Scripts in YAML#

In most cases, developers write automation just to perform some smoke tests, like checking the appearance of some content, or verifying that the key user path is accessible. Maintaining a large test project is unnecessary in this situation.

⁠Midscene offers a way to do this kind of automation with .yaml files, which helps you to focus on the script itself instead of the test infrastructure. Any team member can write an automation script without learning any API.

Here is an example of .yaml script, you may have already understood how it works by reading its content.

target:
  url: https://www.bing.com

tasks:
  - name: search weather
    flow:
      - ai: search for 'weather today'
      - sleep: 3000

  - name: check result
    flow:
      - aiAssert: the result shows the weather info

Preparation#

Config the OpenAI API key in the environment variable

# replace with your own
export OPENAI_API_KEY="sk-abcdefghijklmnopqrstuvwxyz"

or you can use a .env file to store the configuration, Midscene command line tool will automatically load it when running yaml scripts.

OPENAI_API_KEY="sk-abcdefghijklmnopqrstuvwxyz"

For more details about model and provider, see config model and provider

Start#

Install @midscene/cli globally

npm i -g @midscene/cli
# or if you prefer a project-wide installation
npm i @midscene/cli --save-dev

Write a yaml file to bing-search.yaml

target:
  url: https://www.bing.com

tasks:
  - name: search weather
    flow:
      - ai: search for 'weather today'
      - sleep: 3000
      - aiAssert: the result shows the weather info

Run this script

midscene ./bing-search.yaml
# or if you installed midscene inside the project
npx midscene ./bing-search.yaml

You should see that the output shows the progress of the running process and the report file.

Usage in-depth#

Run single .yaml file#

midscene /path/to/yaml

Run all .yaml files under a folder#

midscene /dir/of/yaml/

# glob is also supported
midscene /dir/**/yaml/

Debug in headed mode#

'headed mode' means the browser will be visible. The default behavior is to run in headless mode.

To turn on headed mode, you can use --headed option. Besides, if you want to keep the browser window open after the script finishes, you can use --keep-window option. --keep-window implies --headed.

When running in headed mode, it will consume more resources, so we recommend you to use it locally only when needed.

# run in headed mode
midscene /path/to/yaml --headed

# run in headed mode and keep the browser window open after the script finishes
midscene /path/to/yaml --keep-window

.yaml file schema#

There are two parts in a .yaml file, the target and the tasks.

The target part defines the basic of a task

target:
  # The URL to visit, required. If `serve` is provided, provide the path to the file to visit
  url: <url>

  # Serve the local path as a static server, optional
  serve: <root-directory>

  # The user agent to use, optional
  userAgent: <ua>

  # number, the viewport width, default is 1280, optional
  viewportWidth: <width>

  # number, the viewport height, default is 960, optional
  viewportHeight: <height>

  # number, the device scale factor (dpr), default is 1, optional
  deviceScaleFactor: <scale>

  # string, the path to the json format cookie file, optional
  cookie: <path-to-cookie-file>
  
  # object, the strategy to wait for network idle, optional
  waitForNetworkIdle:
    # number, the timeout in milliseconds, 10000ms for default, optional
    timeout: <ms>
    # boolean, continue on network idle error, true for default
    continueOnNetworkIdleError: <boolean>
  
  # string, the path to save the aiQuery result, optional
  output: <path-to-output-file>

  # boolean, if limit the popup to the current page, true for default in yaml script
  forceSameTabNavigation: <boolean>

  # string, the bridge mode to use, optional, default is false, can be 'newTabWithUrl' or 'currentTab'. More details see the following section
  bridgeMode: false | 'newTabWithUrl' | 'currentTab'

  # boolean, if close the new tabs after the bridge is disconnected, optional, default is false
  closeNewTabsAfterDisconnect: <boolean>

The tasks part is an array indicates the tasks to do. Remember to write a - before each item which means an array item.

tasks:
  - name: <name>
    continueOnError: <boolean> # optional, default is false
    flow:
      # perform an action, this is the shortcut for aiAction
      - ai: <prompt>

      # perform an action
      - aiAction: <prompt>

      # perform an assertion
      - aiAssert: <prompt>

      # perform a query, return a json object
      - aiQuery: <prompt> # remember to describe the format of the result in the prompt
        name: <name> # the name of the result, will be used as the key in the output json

      # wait for a condition to be met with a timeout (ms, optional, default 30000)
      - aiWaitFor: <prompt>
        timeout: <ms>

      # sleep for a number of milliseconds
      - sleep: <ms>

  - name: <name>
    flow:
      # ...

Use environment variables in .yaml file#

You can use environment variables in .yaml file by ${variable-name}.

For example, if you have a .env file with the following content:

topic=weather today

You can use the environment variable in the .yaml file like this:

#...
 - ai: type ${topic} in input box
#...

Use bridge mode#

By using bridge mode, you can utilize YAML scripts to automate the web browser on your desktop. This is particularly useful if you want to reuse cookies, plugins, and page states, or if you want to manually interact with automation scripts.

To use bridge mode, you should install the Chrome extension first, and use this configuration in the target section:

target:
  url: https://www.bing.com
+ bridgeMode: newTabWithUrl

See Bridge Mode by Chrome Extension for more details.

Run yaml script with javascript#

You can also run a yaml script with javascript by using the runYaml method of the Midscene agent. Only the tasks part of the yaml script will be executed.

FAQ#

How to get cookies in JSON format from Chrome?

You can use this chrome extension to export cookies in JSON format.

More#

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