PowerShell WTF

json-array-gotcha.ps1

echo '[1, 2, 3]' | ConvertFrom-Json | measure
# Count: 1

(echo '[1, 2, 3]' | ConvertFrom-Json) | measure
# Count: 3

echo '[1, 2, 3]' | ConvertFrom-Json | ConvertTo-Json
#{
#    "value":  [
#                  1,
#                  2,
#                  3
#              ],
#    "Count":  3
#}

null-test.ps1

PS > [bool] ($null -eq $null)
True                                      # Makes sense
PS > [bool] (@($null) -eq $null)
False                                     # As expected, but not for the reason you think
PS > [bool] (@($null, $null) -eq $null)
True                                      # What?!?
PS > [bool] (-null -eq @($null, $null))
False                 # Hence, "$null should be on the left side of equality comparisons"