Expand-MemberInfo.ps1

function Expand-MemberInfo {
    [Alias('emi')]
    [CmdletBinding()]
    param(
        [Parameter(ValueFromPipeline, Mandatory)]
        [Alias('Member')]
        [psobject] $InputObject,

        [Parameter()]
        [ValidateSet('IL', 'CSharp', 'VisualBasic')]
        [string] $Language = 'CSharp',

        [switch] $NoAnonymousMethods,
        [switch] $NoExpressionTrees,
        [switch] $NoYield,
        [switch] $NoAsync,
        [switch] $NoAutomaticProperties,
        [switch] $NoAutomaticEvents,
        [switch] $NoUsingStatements,
        [switch] $NoForEachStatements,
        [switch] $NoLockStatements,
        [switch] $NoSwitchOnString,
        [switch] $NoUsingDeclarations,
        [switch] $NoQueryExpressions,
        [switch] $DontClarifySameNameTypes,
        [switch] $UseFullnamespace,
        [switch] $DontUseVariableNamesFromSymbols,
        [switch] $NoObjectOrCollectionInitializers,
        [switch] $NoInlineXmlDocumentation,
        [switch] $DontRemoveEmptyDefaultConstructors,
        [switch] $DontUseIncrementOperators,
        [switch] $DontUseAssignmentExpressions,
        [switch] $AlwaysCreateExceptionVariables,
        [switch] $SortMembers,
        [switch] $ShowTokens,
        [switch] $ShowBytes,
        [switch] $ShowPdbInfo
    )
    begin {
        $dnSpy = Get-Command -CommandType Application -Name dnSpy.Console.exe -ErrorAction Stop

        $argumentList = & {
            if ($NoAnonymousMethods.IsPresent) {
                '--no-anon-methods'
            }

            if ($NoExpressionTrees.IsPresent) {
                '--no-expr-trees'
            }

            if ($NoYield.IsPresent) {
                '--no-yield'
            }

            if ($NoAsync.IsPresent) {
                '--no-async'
            }

            if ($NoAutomaticProperties.IsPresent) {
                '--no-auto-props'
            }

            if ($NoAutomaticEvents.IsPresent) {
                '--no-auto-events'
            }

            if ($NoUsingStatements.IsPresent) {
                '--no-using-stmt'
            }

            if ($NoForEachStatements.IsPresent) {
                '--no-foreach-stmt'
            }

            if ($NoLockStatements.IsPresent) {
                '--no-lock-stmt'
            }

            if ($NoSwitchOnString.IsPresent) {
                '--no-switch-string'
            }

            if ($NoUsingDeclarations.IsPresent) {
                '--no-using-decl'
            }

            if ($NoQueryExpressions.IsPresent) {
                '--no-query-expr'
            }

            if ($DontClarifySameNameTypes.IsPresent) {
                '--no-ambig-full-names'
            }

            if ($UseFullnamespace.IsPresent) {
                '--full-names'
            }

            if ($DontUseVariableNamesFromSymbols.IsPresent) {
                '--use-debug-syms'
            }

            if ($NoObjectOrCollectionInitializers.IsPresent) {
                '--no-obj-inits'
            }

            if ($NoInlineXmlDocumentation.IsPresent) {
                '--no-xml-doc'
            }

            if ($DontRemoveEmptyDefaultConstructors.IsPresent) {
                '--dont-remove-empty-ctors'
            }

            if ($DontUseIncrementOperators.IsPresent) {
                '--no-inc-dec'
            }

            if ($DontUseAssignmentExpressions.IsPresent) {
                '--dont-make-assign-expr'
            }

            if ($AlwaysCreateExceptionVariables.IsPresent) {
                '--always-create-ex-var'
            }

            if ($SortMembers.IsPresent) {
                '--sort-members'
            }

            if ($ShowBytes.IsPresent) {
                '--bytes'
            }

            if ($ShowPdbInfo.IsPresent) {
                '--pdb-info'
            }

            if ($Language -ne 'CSharp') {
                $languageGuid = switch ($Language) {
                    IL { '{a4f35508-691f-4bd0-b74d-d5d5d1d0e8e6}' }
                    CSharp { '{bba40092-76b2-4184-8e81-0f1e3ed14e72}' }
                    VisualBasic { '{a4f35508-691f-4bd0-b74d-d5d5d1d0e8e6}' }
                }

                "-l ""$languageGuid"""
            }
        }

        if ($argumentList.Count -gt 1) {
            $arguments = $argumentList -join ' '
            return
        }

        $arguments = [string]$argumentList
    }
    process {
        if ($InputObject -is [PSMethod]) {
            $null = $PSBoundParameters.Remove('InputObject')
            return $InputObject.ReflectionInfo | & $MyInvocation.MyCommand @PSBoundParameters
        }

        if ($InputObject -is [type]) {
            $assembly = $InputObject.Assembly
        } else {
            $assembly = $InputObject.DeclaringType.Assembly
        }

        $sb = [StringBuilder]::new($arguments)
        if ($sb.Length -gt 0) {
            $null = $sb.Append(' ')
        }

        if (-not $ShowTokens.IsPresent) {
            $null = $sb.Append('--no-tokens ')
        }

        try {
            # Use the special name accessor as PowerShell ignores property exceptions.
            $metadataToken = $InputObject.get_MetadataToken()
        } catch [InvalidOperationException] {
            $exception = [PSArgumentException]::new(
                ('Unable to get the metadata token of member "{0}". Ensure ' -f $InputObject) +
                'the target is not dynamically generated and then try the command again.',
                $PSItem)

            $PSCmdlet.WriteError(
                [ErrorRecord]::new(
                    <# exception:     #> $exception,
                    <# errorId:       #> 'CannotGetMetadataToken',
                    <# errorCategory: #> [ErrorCategory]::InvalidArgument,
                    <# targetObject:  #> $InputObject))

            return
        }


        $null = $sb.
            AppendFormat('--md {0} ', $metadataToken).
            AppendFormat('"{0}"', $assembly.Location)

        & ([scriptblock]::Create(('& "{0}" {1}' -f $dnSpy.Source, $sb.ToString())))
    }
}