Fix parsing of empty hashtable when string is provided as settings object

Engine/Settings.cs

@@ -560,11 +560,6 @@ private Hashtable GetHashtableFromHashTableAst(HashtableAst hashTableAst)
                     }
                 }
 
-                if (rhsList.Count == 0)
-                {
-                    ThrowInvalidDataException(kvp.Item2);
-                }
-
                 output[key] = rhsList.ToArray();
             }
 
@@ -629,7 +624,7 @@ private List<string> GetArrayFromArrayExpressionAst(ArrayExpressionAst arrayExp)
                 }
             }
 
-            return null;
+            return result;
         }
 
         private void ThrowInvalidDataException(Ast ast)

Tests/Engine/Settings.tests.ps1

@@ -38,19 +38,23 @@ Describe "Settings Precedence" {
 
 Describe "Settings Class" {
     Context "When an empty hashtable is provided" {
-        BeforeAll {
-            $settings = New-Object -TypeName $settingsTypeName -ArgumentList @{}
-        }
 
         It "Should return empty <name> property" -TestCases @(
             @{ Name = "IncludeRules" }
             @{ Name = "ExcludeRules" }
             @{ Name = "Severity" }
             @{ Name = "RuleArguments" }
-        ) {
-            Param($Name)
+            ) {
+                Param($Name)
 
-            ${settings}.${Name}.Count | Should -Be 0
+                $settings = New-Object -TypeName $settingsTypeName -ArgumentList @{}
+                ${settings}.${Name}.Count | Should -Be 0
+        }
+
+        It "Should be able to parse empty settings hashtable from settings file" {
+            $testPSSASettingsFilePath = "TestDrive:\PSSASettings.psd1"
+            Set-Content $testPSSASettingsFilePath -Value '@{ExcludeRules = @()}'
+            Invoke-ScriptAnalyzer -ScriptDefinition 'gci' -Settings $testPSSASettingsFilePath | Should -Not -BeNullOrEmpty
         }
     }
 
@@ -104,7 +108,7 @@ Describe "Settings Class" {
         It "Should return $expectedNumberOfIncludeRules IncludeRules" {
             $settings.IncludeRules.Count | Should -Be $expectedNumberOfIncludeRules
         }
-        
+
         $expectedNumberOfExcludeRules = 3
         It "Should return $expectedNumberOfExcludeRules ExcludeRules" {
             $settings.ExcludeRules.Count | Should -Be $expectedNumberOfExcludeRules