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/*
This source file is part of the Swift.org open source project
Copyright (c) 2021 Apple Inc. and the Swift project authors
Licensed under Apache License v2.0 with Runtime Library Exception
See https://swift.org/LICENSE.txt for license information
See https://swift.org/CONTRIBUTORS.txt for Swift project authors
*/
import XCTest
@testable import SwiftDocC
class Sequence_MapFirstTests: XCTestCase {
struct Val {
let id: Int
let name: String
}
func testEmpty() {
// Test that the closure is never called for an empty collection.
XCTAssertNil([].mapFirst(where: { "" }))
}
func testNotFound() {
XCTAssertNil([1, 2, 3].mapFirst(where: { _ in nil }))
XCTAssertNil([1, 2, 3].mapFirst(where: { $0 == 100 ? $0 : nil}))
// Should call the closure for each element when no match is found
var values = [Int]()
XCTAssertNil([1, 2, 3].mapFirst(where: { values.append($0); return nil }))
XCTAssertEqual(values, [1, 2, 3])
}
func testFound() {
// Should return a string for the first element
XCTAssertEqual([1, 2, 3].mapFirst(where: { _ in "TEST" }), "TEST")
// Should return a boolean for the first element
XCTAssertEqual([1, 2, 3].mapFirst(where: { $0 == 3 }), false)
// Should return the last element as string
XCTAssertEqual([1, 2, 3].mapFirst(where: { $0 == 3 ? "\($0)" : nil }), "3")
// Should return the name of value with id = 2
let values = [
Val(id: 1, name: "Anna"),
Val(id: 2, name: "Hannah"),
Val(id: 3, name: "Joanna"),
]
XCTAssertEqual(values.mapFirst(where: { value -> String? in
return value.id == 2 ? value.name : nil
}), "Hannah")
// Should call the closure for each element up until the matching one
do {
var values = [Int]()
_ = [1, 2, 3, 4, 5].mapFirst(where: { value -> Bool? in
values.append(value);
return value == 3 ? true : nil
})
XCTAssertEqual(values, [1, 2, 3])
}
}
}
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