Triage test failures with XCTIssue

9:52 - Implement a custom test assertion using XCTIssue

func assertSomething(about data: Data,
                         file: StaticString = #filePath,
                         line: UInt = #line) {

        // Call out to custom validation function.
        if !isValid(data) {

            // Create issue, declare with var for mutability.
            var issue = XCTIssue(type: .assertionFailure, compactDescription: "Invalid data")

            // Attach the invalid data.
            issue.add(XCTAttachment(data: data))

            // Capture the call site location as the point of failure.
            let location = XCTSourceCodeLocation(filePath: file, lineNumber: line)
            issue.sourceCodeContext = XCTSourceCodeContext(location: location)

            // Record the issue.
            self.record(issue)
        }
    }

11:12 - Override record(_ issue:) for observation

override func record(_ issue: XCTIssue) {
        
    // Observe, introspect, log, etc.:
    if shouldLog(issue) {
        print("I just observed an issue!")
    }

    // Don't forget to call super!
    super.record(issue)
}

11:30 - Override record(_ issue:) to suppress failures

override func record(_ issue: XCTIssue) {

    // If you don't want to record it, just return.
    if shouldSuppress(issue) {
        return
    }

    // Otherwise pass it to super.
    super.record(issue)
}

11:39 - Override record(_ issue:) to add an attachment

override func record(_ issue: XCTIssue) {
    
    // Redeclare using var to enable mutation.
    var issue = issue

    // Add a simple attachment.
    issue.add(XCTAttachment(string: "hello"))
    
    // Pass it to super.
    super.record(issue)
}