Ensure null-coalescing LHS is evaluated only once (#12667)

2026-06-08 12:12:50 +00:00 · 2020-05-16 21:36:15 +05:00
parent 270eabc6c4
commit 3dfd95a09f
2 changed files with 26 additions and 10 deletions
@@ -172,6 +172,18 @@ Describe 'NullCoalesceOperations' -Tags 'CI' {
        It 'Lhs is $?' {
            {$???$false} | Should -BeTrue
        }
+
+        It 'Should only evaluate LHS once when it IS null' {
+            $testState = [pscustomobject]@{ Value = 0 }
+            (& { [void]$testState.Value++ }) ?? 'Nothing' | Should -BeExactly 'Nothing'
+            $testState.Value | Should -Be 1
+        }
+
+        It 'Should only evaluate LHS once when it is NOT null' {
+            $testState = [pscustomobject]@{ Value = 0 }
+            (& { 'Test'; [void]$testState.Value++ }) ?? 'Nothing' | Should -BeExactly 'Test'
+            $testState.Value | Should -Be 1
+        }
    }

    Context 'Null Coalesce ?? operator precedence' {