| 1 | // Copyright 2022 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | // This file contains tests that the loopclosure analyzer detects leaked |
| 6 | // references via parallel subtests. |
| 7 | |
| 8 | package subtests |
| 9 | |
| 10 | import ( |
| 11 | "testing" |
| 12 | ) |
| 13 | |
| 14 | // T is used to test that loopclosure only matches T.Run when T is from the |
| 15 | // testing package. |
| 16 | type T struct{} |
| 17 | |
| 18 | // Run should not match testing.T.Run. Note that the second argument is |
| 19 | // intentionally a *testing.T, not a *T, so that we can check both |
| 20 | // testing.T.Parallel inside a T.Run, and a T.Parallel inside a testing.T.Run. |
| 21 | func (t *T) Run(string, func(*testing.T)) { |
| 22 | } |
| 23 | |
| 24 | func (t *T) Parallel() {} |
| 25 | |
| 26 | func _(t *testing.T) { |
| 27 | for i, test := range []int{1, 2, 3} { |
| 28 | // Check that parallel subtests are identified. |
| 29 | t.Run("", func(t *testing.T) { |
| 30 | t.Parallel() |
| 31 | println(i) // want "loop variable i captured by func literal" |
| 32 | println(test) // want "loop variable test captured by func literal" |
| 33 | }) |
| 34 | |
| 35 | // Check that serial tests are OK. |
| 36 | t.Run("", func(t *testing.T) { |
| 37 | println(i) |
| 38 | println(test) |
| 39 | }) |
| 40 | |
| 41 | // Check that the location of t.Parallel matters. |
| 42 | t.Run("", func(t *testing.T) { |
| 43 | println(i) |
| 44 | println(test) |
| 45 | t.Parallel() |
| 46 | println(i) // want "loop variable i captured by func literal" |
| 47 | println(test) // want "loop variable test captured by func literal" |
| 48 | }) |
| 49 | |
| 50 | // Check that *testing.T value matters. |
| 51 | t.Run("", func(t *testing.T) { |
| 52 | var x testing.T |
| 53 | x.Parallel() |
| 54 | println(i) |
| 55 | println(test) |
| 56 | }) |
| 57 | |
| 58 | // Check that shadowing the loop variables within the test literal is OK if |
| 59 | // it occurs before t.Parallel(). |
| 60 | t.Run("", func(t *testing.T) { |
| 61 | i := i |
| 62 | test := test |
| 63 | t.Parallel() |
| 64 | println(i) |
| 65 | println(test) |
| 66 | }) |
| 67 | |
| 68 | // Check that shadowing the loop variables within the test literal is Not |
| 69 | // OK if it occurs after t.Parallel(). |
| 70 | t.Run("", func(t *testing.T) { |
| 71 | t.Parallel() |
| 72 | i := i // want "loop variable i captured by func literal" |
| 73 | test := test // want "loop variable test captured by func literal" |
| 74 | println(i) // OK |
| 75 | println(test) // OK |
| 76 | }) |
| 77 | |
| 78 | // Check uses in nested blocks. |
| 79 | t.Run("", func(t *testing.T) { |
| 80 | t.Parallel() |
| 81 | { |
| 82 | println(i) // want "loop variable i captured by func literal" |
| 83 | println(test) // want "loop variable test captured by func literal" |
| 84 | } |
| 85 | }) |
| 86 | |
| 87 | // Check that we catch uses in nested subtests. |
| 88 | t.Run("", func(t *testing.T) { |
| 89 | t.Parallel() |
| 90 | t.Run("", func(t *testing.T) { |
| 91 | println(i) // want "loop variable i captured by func literal" |
| 92 | println(test) // want "loop variable test captured by func literal" |
| 93 | }) |
| 94 | }) |
| 95 | |
| 96 | // Check that there is no diagnostic if t is not a *testing.T. |
| 97 | t.Run("", func(_ *testing.T) { |
| 98 | t := &T{} |
| 99 | t.Parallel() |
| 100 | println(i) |
| 101 | println(test) |
| 102 | }) |
| 103 | |
| 104 | // Check that there is no diagnostic when a jump to a label may have caused |
| 105 | // the call to t.Parallel to have been skipped. |
| 106 | t.Run("", func(t *testing.T) { |
| 107 | if true { |
| 108 | goto Test |
| 109 | } |
| 110 | t.Parallel() |
| 111 | Test: |
| 112 | println(i) |
| 113 | println(test) |
| 114 | }) |
| 115 | |
| 116 | // Check that there is no diagnostic when a jump to a label may have caused |
| 117 | // the loop variable reference to be skipped, but there is a diagnostic |
| 118 | // when both the call to t.Parallel and the loop variable reference occur |
| 119 | // after the final label in the block. |
| 120 | t.Run("", func(t *testing.T) { |
| 121 | if true { |
| 122 | goto Test |
| 123 | } |
| 124 | t.Parallel() |
| 125 | println(i) // maybe OK |
| 126 | Test: |
| 127 | t.Parallel() |
| 128 | println(test) // want "loop variable test captured by func literal" |
| 129 | }) |
| 130 | |
| 131 | // Check that multiple labels are handled. |
| 132 | t.Run("", func(t *testing.T) { |
| 133 | if true { |
| 134 | goto Test1 |
| 135 | } else { |
| 136 | goto Test2 |
| 137 | } |
| 138 | Test1: |
| 139 | Test2: |
| 140 | t.Parallel() |
| 141 | println(test) // want "loop variable test captured by func literal" |
| 142 | }) |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | // Check that there is no diagnostic when loop variables are shadowed within |
| 147 | // the loop body. |
| 148 | func _(t *testing.T) { |
| 149 | for i, test := range []int{1, 2, 3} { |
| 150 | i := i |
| 151 | test := test |
| 152 | t.Run("", func(t *testing.T) { |
| 153 | t.Parallel() |
| 154 | println(i) |
| 155 | println(test) |
| 156 | }) |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | // Check that t.Run must be *testing.T.Run. |
| 161 | func _(t *T) { |
| 162 | for i, test := range []int{1, 2, 3} { |
| 163 | t.Run("", func(t *testing.T) { |
| 164 | t.Parallel() |
| 165 | println(i) |
| 166 | println(test) |
| 167 | }) |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | // Check that the top-level must be parallel in order to cause a diagnostic. |
| 172 | // |
| 173 | // From https://pkg.go.dev/testing: |
| 174 | // |
| 175 | // "Run does not return until parallel subtests have completed, providing a |
| 176 | // way to clean up after a group of parallel tests" |
| 177 | func _(t *testing.T) { |
| 178 | for _, test := range []int{1, 2, 3} { |
| 179 | // In this subtest, a/b must complete before the synchronous subtest "a" |
| 180 | // completes, so the reference to test does not escape the current loop |
| 181 | // iteration. |
| 182 | t.Run("a", func(s *testing.T) { |
| 183 | s.Run("b", func(u *testing.T) { |
| 184 | u.Parallel() |
| 185 | println(test) |
| 186 | }) |
| 187 | }) |
| 188 | |
| 189 | // In this subtest, c executes concurrently, so the reference to test may |
| 190 | // escape the current loop iteration. |
| 191 | t.Run("c", func(s *testing.T) { |
| 192 | s.Parallel() |
| 193 | s.Run("d", func(u *testing.T) { |
| 194 | println(test) // want "loop variable test captured by func literal" |
| 195 | }) |
| 196 | }) |
| 197 | } |
| 198 | } |
| 199 |
Members