fix module manifest update logic

src/Build/Update-ModuleMeta.Tests.ps1

@@ -18,4 +18,40 @@ Describe 'Update-ModuleMeta' {
             $foo.Description[0].Text.Length | Should -BeGreaterThan 5
         }
     }
+
+    Context 'Unit Tests' -Tag 'Unit' {
+        BeforeAll {
+            # Mock Drone env if its not present
+            if (!$Env:DRONE) {
+                $Env:DRONE = $true
+                $Env:DRONE_BUILD_EVENT = 'tag'
+                $Env:DRONE_SEMVER = '9.9.9-dev9'
+                $Env:DRONE_SEMVER_SHORT = '9.9.9'
+                $Env:DRONE_SEMVER_PRERELEASE = 'dev9'
+            }
+            Mock 'Get-RepoPath' -ModuleName 'DroneHelper' {
+                return @{
+                    Src = @{
+                        Manifest = @{
+                            Item = @{
+                                FullName = './resources/MyModule.psd1'
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        It 'Update test module manifest' {
+            { Update-ModuleMeta } | Should -Not -Throw
+        }
+
+        It 'Updated manifest is valid' {
+            { Test-ModuleManifest -Path './resources/MyModule.psd1' } | Should -Not -Throw
+        }
+
+        It 'External dependencies prop is untouched' {
+            $d = Test-ModuleManifest -Path './resources/MyModule.psd1'
+            $d.PrivateData.PSData.ExternalModuleDependencies.Count | Should -Be '2'
+        }
+    }
 }

src/Build/Update-ModuleMeta.ps1

@@ -39,22 +39,53 @@ function Update-ModuleMeta {
                     if ($null -ne $Env:DRONE_SEMVER_PRERELEASE) {
                         $nPreRelease = $Env:DRONE_SEMVER_PRERELEASE
                     }
-                    $ModManifestParams = @{
+                    $DataParams = @{
                         Path        = $Repo.Src.Manifest.Item.FullName
-                        ModuleVersion = $nVersion
                         ErrorAction = 'Stop'
                     }
+                    # Getting the module manifest as imported object
+                    try {
+                        $ModManifestData = Import-PowerShellDataFile @DataParams
+                    }
+                    catch {
+                        $_.Exception.Message | Write-Debug
+                        $ErrorParams = @{
+                            Message     = "Could not import the module manifest file."
+                            ErrorAction = 'Stop'
+                        }
+                        Write-Error @ErrorParams
+                    }
+                    # Updating the new module version
+                    $ModManifestData.ModuleVersion = $nVersion
+
+                    # Updating the prerelease property if there is one
                     if ($nPreRelease) {
-                        $ModManifestParams.PreRelease = $nPreRelease
+                        $ModManifestData.PrivateData.PSData.Prerelease = $nPreRelease
                     }
 
                     $ManifestData = Test-ModuleManifest -Path $Repo.Src.Manifest.Item.FullName
 
                     if (
                         ($nVersion -ne $ManifestData.Version) -or
-                        ($nVersion -ne $ManifestData.PrivateData.PSData.Prerelease)
+                        ($nPreRelease -ne $ManifestData.PrivateData.PSData.Prerelease)
                     ) {
-                        Update-ModuleManifest @ModManifestParams
+                        $OutputFileParams = @{
+                            Path     = $Repo.Src.Manifest.Item.FullName
+                            PassThru = $true
+                            Encoding = 'utf8NoBom'
+                            Force    = $true
+                        }
+                        try {
+                            $ModManifestData | ConvertTo-Psd | Set-Content @OutputFileParams
+                        }
+                        catch {
+                            $_.Exception.Message | Write-Debug
+                            $ErrorParams = @{
+                                Message     = "Failed to update the module manifest file"
+                                ErrorAction = 'Stop'
+                            }
+                            Write-Error @ErrorParams
+                        }
                     }
                     else {
                         Write-Verbose -Message 'Identical version given. Skipping update.'