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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
|
//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2025 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
//
//===----------------------------------------------------------------------===//
@_spi(Rules) import SwiftFormat
import _SwiftFormatTestSupport
final class UseExplicitNilCheckInConditionsTests: LintOrFormatRuleTestCase {
func testIfExpressions() {
assertFormatting(
UseExplicitNilCheckInConditions.self,
input: """
if 1️⃣let _ = x {}
if let x = y, 2️⃣let _ = x.m {}
if let x = y {} else if 3️⃣let _ = z {}
""",
expected: """
if x != nil {}
if let x = y, x.m != nil {}
if let x = y {} else if z != nil {}
""",
findings: [
FindingSpec("1️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
FindingSpec("2️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
FindingSpec("3️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
]
)
}
func testGuardStatements() {
assertFormatting(
UseExplicitNilCheckInConditions.self,
input: """
guard 1️⃣let _ = x else {}
guard let x = y, 2️⃣let _ = x.m else {}
""",
expected: """
guard x != nil else {}
guard let x = y, x.m != nil else {}
""",
findings: [
FindingSpec("1️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
FindingSpec("2️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
]
)
}
func testWhileStatements() {
assertFormatting(
UseExplicitNilCheckInConditions.self,
input: """
while 1️⃣let _ = x {}
while let x = y, 2️⃣let _ = x.m {}
""",
expected: """
while x != nil {}
while let x = y, x.m != nil {}
""",
findings: [
FindingSpec("1️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
FindingSpec("2️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
]
)
}
func testTriviaPreservation() {
assertFormatting(
UseExplicitNilCheckInConditions.self,
input: """
if /*comment*/ 1️⃣let _ = x /*comment*/ {}
if 2️⃣let _ = x // comment
{}
""",
expected: """
if /*comment*/ x != nil /*comment*/ {}
if x != nil // comment
{}
""",
findings: [
FindingSpec("1️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
FindingSpec("2️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
]
)
}
func testDoNotDropTrailingCommaInConditionList() {
assertFormatting(
UseExplicitNilCheckInConditions.self,
input: """
if 1️⃣let _ = x, 2️⃣let _ = y {}
""",
expected: """
if x != nil, y != nil {}
""",
findings: [
FindingSpec("1️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
FindingSpec("2️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
]
)
}
func testAddNecessaryParenthesesAroundTryExpr() {
assertFormatting(
UseExplicitNilCheckInConditions.self,
input: """
if 1️⃣let _ = try? x {}
if 2️⃣let _ = try x {}
""",
expected: """
if (try? x) != nil {}
if (try x) != nil {}
""",
findings: [
FindingSpec("1️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
FindingSpec("2️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
]
)
}
func testAddNecessaryParenthesesAroundTernaryExpr() {
assertFormatting(
UseExplicitNilCheckInConditions.self,
input: """
if 1️⃣let _ = x ? y : z {}
""",
expected: """
if (x ? y : z) != nil {}
""",
findings: [
FindingSpec("1️⃣", message: "compare this value using `!= nil` instead of binding and discarding it")
]
)
}
func testAddNecessaryParenthesesAroundSameOrLowerPrecedenceOperator() {
// The use of `&&` and `==` are semantically meaningless here because they don't return
// optionals. We just need them to stand in for any potential custom operator with lower or same
// precedence, respectively.
assertFormatting(
UseExplicitNilCheckInConditions.self,
input: """
if 1️⃣let _ = x && y {}
if 2️⃣let _ = x == y {}
""",
expected: """
if (x && y) != nil {}
if (x == y) != nil {}
""",
findings: [
FindingSpec("1️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
FindingSpec("2️⃣", message: "compare this value using `!= nil` instead of binding and discarding it"),
]
)
}
}
|
