compare method Null safety

Future<bool> compare(
  1. double width,
  2. double height,
  3. Uri golden

Compares the rendered pixels of size widthxheight that is being rendered on the top left of the screen against the golden file identified by golden.

The returned future completes with a boolean value that indicates whether the pixels rendered on screen match the golden file's pixels.

In the case of comparison mismatch, the comparator may choose to throw a TestFailure if it wants to control the failure message, often in the form of a ComparisonResult that provides detailed information about the mismatch.

The method by which golden is located and by which its bytes are loaded is left up to the implementation class. For instance, some implementations may load files from the local file system, whereas others may load files over the network or from a remote repository.


Future<bool> compare(double width, double height, Uri golden);