Allow custom messages in expect()

[clayreimann]

• I have read CONTRIBUTING and have done my best to follow them.

What did you do?

for (tag, title) in defaultRows {
    let row = entryForm.row(tag: tag)
    expect(row.exists) == true
    expect(row.staticTexts["title"].label) == title
}

What did you expect to happen?

I would like to be able to provide custom message to expect so that I can see which loop iteration failed.

for (tag, title) in defaultRows {
    let row = entryForm.row(tag: tag)
    expect(row.exists, message: "\(tag) exists") == true
// or maybe more briefly
//    expect(row.exists, "\(tag) exists") == true
    expect(row.staticTexts["title"].label) == title
}

I'd be willing to submit a PR if this feature fits with the project

Environment

List the software versions you're using:

• Quick: Nope
• Nimble: 7.1.3
• Xcode Version: 9.4.1 (9F2000)
• Swift Version: Xcode Default
• Carthage: 0.30.1

[ikesyo]

The functionality is provided by to(_:description:)

Nimble/Tests/NimbleTests/UserDescriptionTest.swift

Line 12 in f52c57e

expect(1).to(MatcherFunc { _, _ in false }, description: "These aren't equal!")

[clayreimann]

Which is incompatible with the infix operators. Chai provides a similar api for their assertions that aren't function calls.

[clayreimann]

@ikesyo Any comment on this? Would such a PR be accepted?

[ikesyo]

It seems that this would be important with regard to #493.

[ikesyo]

I'm now working on this in relation to #369 and #742.