CompleteInput fails when passed an empty string/AST #5743
Description
Steps to reproduce
[System.Management.Automation.CommandCompletion]::CompleteInput('', 0, @{})Or
[System.Management.Automation.CommandCompletion]::CompleteInput(
{}.Ast,
@(),
{}.Ast.Extent.StartScriptPosition,
@{})Expected behavior
CurrentMatchIndex ReplacementIndex ReplacementLength CompletionMatches
----------------- ---------------- ----------------- -----------------
-1 0 0 {}
Alternatively if throwing is a design choice, throw an ArgumentException instead of letting Enumerable.Last fail.
Actual behavior
> [System.Management.Automation.CommandCompletion]::CompleteInput('', 0, @{})
Exception calling "CompleteInput" with "3" argument(s): "Sequence contains no elements"
At line:1 char:1
+ [System.Management.Automation.CommandCompletion]::CompleteInput('', 0 ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : InvalidOperationException
> $Error[0].Exception.InnerException | Format-List * -Force
Message : Sequence contains no elements
Data : {}
InnerException :
TargetSite : TSource Last[TSource](System.Collections.Generic.IEnumerable`1[TSource])
StackTrace : at System.Linq.Enumerable.Last[TSource](IEnumerable`1 source)
at
System.Management.Automation.CompletionAnalysis.InitializeCompletionContext(TypeInferenceContext
typeInferenceContext)
at System.Management.Automation.CompletionAnalysis.GetResults(PowerShell powerShell, Int32&
replacementIndex, Int32& replacementLength)
at System.Management.Automation.CommandCompletion.CompleteInputImpl(Ast ast, Token[] tokens,
IScriptPosition positionOfCursor, Hashtable options)
at System.Management.Automation.CommandCompletion.CompleteInput(String input, Int32 cursorIndex,
Hashtable options)
at CallSite.Target(Closure , CallSite , Type , String , Int32 , Hashtable )
HelpLink :
Source : System.Linq
HResult : -2146233079
Environment data
> $PSVersionTable
Name Value
---- -----
PSVersion 6.0.0-rc.2
PSEdition Core
GitCommitId v6.0.0-rc.2
OS Microsoft Windows 10.0.15063
Platform Win32NT
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0