Make yaml dependency self-contained

powershell-yaml wraps YamlDotNet, but hasn't been updated in a while.  the mechanism it uses for ConvertFrom-Yaml uses Parser which throws duplicate key exceptions.  Deserialize does not throw duplicate key exceptions.

Given it's common to have duplication in gitlab CI yaml, allowing overlap/merging is better than throwing

README.md

@@ -227,5 +227,6 @@ Your application
 ## References / Acknowledgements
 
 * [PSGitLab](https://github.com/ngetchell/PSGitLab)
-* [python-gitlab CLI documentation](https://python-gitlab.readthedocs.io/en/stable/)
-* [GitLab API docs](https://docs.gitlab.com/ee/api/)
+* [python-gitlab CLI documentation](https://python-gitlab.readthedocs.io/en/stable)
+* [GitLab API docs](https://docs.gitlab.com/ee/api)
+* [powershell-yaml](https://github.com/cloudbase/powershell-yaml)

src/GitlabCli/GitlabCli.psd1

@@ -43,13 +43,13 @@
     # ProcessorArchitecture = ''
 
     # Modules that must be imported into the global environment prior to importing this module
-    RequiredModules = @('powershell-yaml')
+    # RequiredModules = @()
 
     # Assemblies that must be loaded prior to importing this module
     # RequiredAssemblies = @()
 
     # Script files (.ps1) that are run in the caller's environment prior to importing this module.
-    # ScriptsToProcess = @()
+    ScriptsToProcess = @('_Init.ps1')
 
     # Type files (.ps1xml) to be loaded when importing this module
     TypesToProcess = @('Types.ps1xml')

src/GitlabCli/RepositoryFiles.psm1

@@ -61,5 +61,11 @@ function Get-GitlabCiYml {
         $WhatIf
     )
 
-    New-Object 'psobject' -Property $(ConvertFrom-Yaml $(Get-GitlabRepositoryFileContent -ProjectId $ProjectId -Ref $Ref -FilePath '.gitlab-ci.yml' -SiteUrl $SiteUrl -WhatIf:$WhatIf))
+    $Yml = $(Get-GitlabRepositoryFileContent -ProjectId $ProjectId -Ref $Ref -FilePath '.gitlab-ci.yml' -SiteUrl $SiteUrl -WhatIf:$WhatIf)
+    $Hash = $([YamlDotNet.Serialization.Deserializer].GetMethods() |
+        Where-Object { $_.Name -eq 'Deserialize' -and $_.ReturnType.Name -eq 'T' -and $_.GetParameters().ParameterType.Name -eq 'String' }). `
+        MakeGenericMethod(
+            [object]). `
+        Invoke($(New-Object 'YamlDotNet.Serialization.Deserializer'), $Yml)
+    New-Object 'psobject' -Property $Hash
 }

src/GitlabCli/_Init.ps1

@@ -0,0 +1,33 @@
+# Adapted from
+# https://github.com/cloudbase/powershell-yaml/blob/master/Load-Assemblies.ps1
+
+$Here = Split-Path -Parent $MyInvocation.MyCommand.Path
+
+function Initialize-Assembly {
+    $LibDir = Join-Path $Here "lib"
+
+    return [Reflection.Assembly]::LoadFrom($(Join-Path $libDir "YamlDotNet.dll"))
+}
+
+function Initialize-Assemblies {
+    $RequiredTypes = @(
+        "Parser", "MergingParser", "YamlStream",
+        "YamlMappingNode", "YamlSequenceNode",
+        "YamlScalarNode", "ChainedEventEmitter",
+        "Serializer", "Deserializer", "SerializerBuilder",
+        "StaticTypeResolver"
+    )
+
+    $YamlDotNet = [System.AppDomain]::CurrentDomain.GetAssemblies() | Where-Object Location -Match "YamlDotNet.dll"
+    if (!$YamlDotNet) {
+        return Initialize-Assembly
+    }
+
+    foreach ($i in $RequiredTypes){
+        if ($i -notin $YamlDotNet.DefinedTypes.Name) {
+            throw "YamlDotNet is loaded but missing required types ($i). Older version installed on system?"
+        }
+    }
+}
+
+Initialize-Assemblies | Out-Null