René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Using a dynamicparam block in an advanced function causes invocations with the -PipelineVariable common parameter to fail","articleBody":"An (adapted) copy of [this uservoice issue](https://windowsserver.uservoice.com/forums/301869/suggestions/11088336) first reported by @PetSerAl  in 2014:\r\n\r\nUsing a `dynamicparam` block in an advanced function causes invocations with the `-PipelineVariable` common parameter to fail.\r\n\r\nSteps to reproduce\r\n------------------\r\n\r\n```powershell\r\n\r\nfunction foo {\r\n  [CmdletBinding()]\r\n  param()\r\n  dynamicparam { }\r\n  process { 'hi' }\r\n}\r\n\r\nfoo -PipelineVariable bar\r\n```\r\n\r\nExpected behavior\r\n-----------------\r\n\r\n```none\r\nhi\r\n```\r\n\r\nActual behavior\r\n---------------\r\n\r\nThe following error is reported:\r\n\r\n```none\r\nfoo : Cannot retrieve the dynamic parameters for the cmdlet. Object reference not set to an instance of an object.\r\n...\r\n```\r\n\r\nNote that it doesn't make a difference whether the `dynamicparam` block is empty or not.\r\n\r\nEnvironment data\r\n----------------\r\n\r\n```powershell\r\nPowerShell Core v6.0.2 on macOS 10.13.3\r\nPowerShell Core v6.0.2 on Ubuntu 16.04.3 LTS\r\nPowerShell Core v6.0.2 on Microsoft Windows 10 Pro (64-bit; v10.0.15063)\r\nWindows PowerShell v5.1.15063.674 on Microsoft Windows 10 Pro (64-bit; v10.0.15063)\r\n```\r\n","author":{"url":"https://github.com/mklement0","@type":"Person","name":"mklement0"},"datePublished":"2018-03-17T18:44:44.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":3},"url":"https://github.com/6420/PowerShell/issues/6420"}