1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2023 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 the list of Swift project authors
//
//===----------------------------------------------------------------------===//
/// Defines the location at which the a test failure should be anchored. This is typically the location where the
/// assertion function is called.
public struct TestFailureLocation {
public let fileID: StaticString
public let filePath: StaticString
public let line: UInt
public let column: UInt
public init(
fileID: StaticString,
filePath: StaticString,
line: UInt,
column: UInt
) {
self.fileID = fileID
self.filePath = filePath
self.line = line
self.column = column
}
}
/// Defines the details of a test failure, consisting of a message and the location at which the test failure should be
/// shown.
public struct TestFailureSpec {
public let message: String
public let location: TestFailureLocation
}
/// Asserts that the two strings are equal, providing Unix `diff`-style output if they are not.
///
/// - Parameters:
/// - actual: The actual string.
/// - expected: The expected string.
/// - message: An optional description of the failure.
/// - additionalInfo: Additional information about the failed test case that will be printed after the diff
/// - file: The file in which failure occurred. Defaults to the file name of the test case in
/// which this function was called.
/// - line: The line number on which failure occurred. Defaults to the line number on which this
/// function was called.
public func assertStringsEqualWithDiff(
_ actual: String,
_ expected: String,
_ message: String = "",
additionalInfo: @autoclosure () -> String? = nil,
location: TestFailureLocation,
failureHandler: (TestFailureSpec) -> Void
) {
if actual == expected {
return
}
failStringsEqualWithDiff(
actual,
expected,
message,
additionalInfo: additionalInfo(),
location: location,
failureHandler: failureHandler
)
}
/// `XCTFail` with `diff`-style output.
public func failStringsEqualWithDiff(
_ actual: String,
_ expected: String,
_ message: String = "",
additionalInfo: @autoclosure () -> String? = nil,
location: TestFailureLocation,
failureHandler: (TestFailureSpec) -> Void
) {
let stringComparison: String
// Use `CollectionDifference` on supported platforms to get `diff`-like line-based output. On
// older platforms, fall back to simple string comparison.
let actualLines = actual.split(separator: "\n")
let expectedLines = expected.split(separator: "\n")
let difference = actualLines.difference(from: expectedLines)
var result = ""
var insertions = [Int: Substring]()
var removals = [Int: Substring]()
for change in difference {
switch change {
case .insert(let offset, let element, _):
insertions[offset] = element
case .remove(let offset, let element, _):
removals[offset] = element
}
}
var expectedLine = 0
var actualLine = 0
while expectedLine < expectedLines.count || actualLine < actualLines.count {
if let removal = removals[expectedLine] {
result += "–\(removal)\n"
expectedLine += 1
} else if let insertion = insertions[actualLine] {
result += "+\(insertion)\n"
actualLine += 1
} else {
result += " \(expectedLines[expectedLine])\n"
expectedLine += 1
actualLine += 1
}
}
stringComparison = result
var fullMessage = """
\(message.isEmpty ? "Actual output does not match the expected" : message)
\(stringComparison)
"""
if let additional = additionalInfo() {
fullMessage = """
\(fullMessage)
\(additional)
"""
}
failureHandler(TestFailureSpec(message: fullMessage, location: location))
}
|
