Global

Methods

onSnapDefinitionsFromWindow() → {Promise}

Enables executing code at to compute SnapDefintions at runtime.

Source:
Returns:
Type:
Promise

Type Definitions

onPostSnap()

Run code after a snap has been captured. See onPreSnap.

Source:
See:

onPreSnap(snapDefinition, browserName, browserDriver) → {Promise}

Run arbitrary code before snapDefinition.selector is captured.

WARNING this code must be serializable, or serialized in advanced. This is because this code is run by a different process--a docker processes. Because we execute in a docker context, the docker process is responsible for calling the method. Therefore, make this code as simple as possible, or if you absolutely must have complexity here (please don't), you can bundle your JS into a string and eval it in. PRs welcome if folks want to build in rollup/webpack/etc to do this automatically.

Source:
Parameters:
Name Type Description
snapDefinition SnapDefinition

snap definition for element about to be captured
browserName string

chrome, firefox, etc
browserDriver *

browser adapter used to perform screenshots
Returns:
Type:
Promise

can be async or sync.

Example
// example: run code in the browser context to ready it for snapping
// https://github.com/GoogleChrome/puppeteer/blob/6512ce768ddce790095e2201d8ada3c24407fc57/docs/api.md#pageevaluatepagefunction-args
{
  selector: '#test',
  name: 'test',
  onPreSnap: function revealElement (snapDefinition, browserName, browserDriver) {
    if (browserName.match(/chrome/i)) {
      browserDriver.evaluate(function revealElement (selector) {
        return window.myApp.show(selector)
      }, snapDefinition.selector)
    }
  }
}

SnapDefinition

Properties:
Name Type Attributes Description
selector string

css selector for single element to capture
name string

basename for .png file
onPreSnap onPreSnap <optional>

run code before a capture
onPostSnap onPostSnap <optional>

run code after a capture
Source:

SnapsConfig

Properties:
Name Type Attributes Default Description
staticDirectory string
runId Number <optional>
 Date.now()
url string <optional>
snapDefinitions Array.<SnapDefinition> <optional>
snapDefinitionsFromWindow onSnapDefinitionsFromWindow <optional>
snapRunRoot string <optional>
 `pwd`/snaps/run
snapRefRoot string <optional>
 `pwd`/snaps/ref
report boolean <optional>
 true

generate a static web-application to highlight image changes. report will be placed into snaps/run/-diff
Source: