Report call site for expect() call. Returns the number of frames that
should be elided if a stack were to be modified to hide the expect call, or
zero if no such call was found.
If the head of the stack trace consists of a failure as a result of calling the test_widgets expect function, this will fill the given StringBuffer with the precise file and line number that called that function.
Source
int reportExpectCall(StackTrace stack, StringBuffer information) {
final RegExp line0 = new RegExp(r'^#0 +fail \(.+\)$');
final RegExp line1 = new RegExp(r'^#1 +expect \(.+\)$');
final RegExp line2 = new RegExp(r'^#2 +expect \(.+\)$');
final RegExp line3 = new RegExp(r'^#3 +[^(]+ \((.+?):([0-9]+)(?::[0-9]+)?\)$');
final List<String> stackLines = stack.toString().split('\n');
if (line0.firstMatch(stackLines[0]) != null &&
line1.firstMatch(stackLines[1]) != null &&
line2.firstMatch(stackLines[2]) != null) {
Match expectMatch = line3.firstMatch(stackLines[3]);
assert(expectMatch != null);
assert(expectMatch.groupCount == 2);
information.writeln('This was caught by the test expectation on the following line:');
information.writeln(' ${expectMatch.group(1)} line ${expectMatch.group(2)}');
return 3;
}
return 0;
}