Add tabbed indentation capability to UseConsistentIndentation rule

Engine/Settings/CodeFormatting.psd1

@@ -24,6 +24,7 @@
 
         PSUseConsistentIndentation = @{
             Enable          = $true
+            Kind            = 'space'
             IndentationSize = 4
         }
 

Engine/Settings/CodeFormattingAllman.psd1

@@ -24,6 +24,7 @@
 
         PSUseConsistentIndentation = @{
             Enable          = $true
+            Kind            = 'space'
             IndentationSize = 4
         }
 

Engine/Settings/CodeFormattingOTBS.psd1

@@ -24,6 +24,7 @@
 
         PSUseConsistentIndentation = @{
             Enable          = $true
+            Kind            = 'space'
             IndentationSize = 4
         }
 

Engine/Settings/CodeFormattingStroustrup.psd1

@@ -25,6 +25,7 @@
 
         PSUseConsistentIndentation = @{
             Enable          = $true
+            Kind            = 'space'
             IndentationSize = 4
         }
 

RuleDocumentation/UseConsistentIndentation.md

@@ -28,3 +28,10 @@ Enable or disable the rule during ScriptAnalyzer invocation.
 #### IndentationSize: bool (Default value is `4`)
 
 Indentation size in the number of space characters.
+
+#### Kind: string (Default value is `space`)
+
+Represents the kind of indentation to be used. Possible values are: `space`, `tab`. If any invalid value is given, the property defaults to `space`.
+
+`space` means `IndentationSize` number of `space` characters are used to provide one level of indentation.
+`tab` means a tab character, `\t`.

Rules/UseConsistentIndentation.cs

@@ -36,10 +36,48 @@ public class UseConsistentIndentation : ConfigurableRule
         [ConfigurableRuleProperty(defaultValue: 4)]
         public int IndentationSize { get; protected set; }
 
-        private enum IndentationKind { Space, Tab };
+
+        // Cannot name to IndentationKind due to the enum type of the same name.
+        /// <summary>
+        /// Represents the kind of indentation to be used.
+        ///
+        /// Possible values are: `space`, `tab`. If any invalid value is given, the
+        /// property defaults to `space`.
+        ///
+        /// `space` means `IndentationSize` number of `space` characters are used to provide one level of indentation.
+        /// `tab` means a tab character, `\t`.
+        ///</summary>
+        [ConfigurableRuleProperty(defaultValue: "space")]
+        public string Kind
+        {
+            get
+            {
+                return indentationKind.ToString();
+            }
+            set
+            {
+                if (String.IsNullOrWhiteSpace(value) ||
+                    !Enum.TryParse<IndentationKind>(value, true, out indentationKind))
+                {
+                    indentationKind = IndentationKind.Space;
+                }
+            }
+        }
+
+        private bool insertSpaces;
+        private char indentationChar;
+        private int indentationLevelMultiplier;
+
+        // TODO Enable auto when the rule is able to detect indentation
+        private enum IndentationKind {
+            Space,
+            Tab,
+            // Auto
+        };
 
         // TODO make this configurable
-        private readonly IndentationKind indentationKind = IndentationKind.Space;
+        private IndentationKind indentationKind = IndentationKind.Space;
+
 
         /// <summary>
         /// Analyzes the given ast to find violations.
@@ -61,6 +99,14 @@ public override IEnumerable<DiagnosticRecord> AnalyzeScript(Ast ast, string file
                 return Enumerable.Empty<DiagnosticRecord>();
             }
 
+            // It is more efficient to initialize these fields in ConfigurRule method
+            // but when the rule will enable `Auto` IndentationKind, we will anyways need to move
+            // the setting of these variables back here after the rule detects the indentation kind for
+            // each invocation.
+            insertSpaces = indentationKind == IndentationKind.Space;
+            indentationChar = insertSpaces ? ' ' : '\t';
+            indentationLevelMultiplier = insertSpaces ? IndentationSize : 1;
+
             var tokens = Helper.Instance.Tokens;
             var diagnosticRecords = new List<DiagnosticRecord>();
             var indentationLevel = 0;
@@ -262,17 +308,13 @@ private int GetIndentationColumnNumber(int indentationLevel)
 
         private int GetIndentation(int indentationLevel)
         {
-            return indentationLevel * this.IndentationSize;
-        }
-
-        private char GetIndentationChar()
-        {
-            return indentationKind == IndentationKind.Space ? ' ' : '\t';
+            // todo if condition can be evaluated during rule configuration
+            return indentationLevel * indentationLevelMultiplier;
         }
 
         private string GetIndentationString(int indentationLevel)
         {
-            return new string(GetIndentationChar(), GetIndentation(indentationLevel));
+            return new string(indentationChar, GetIndentation(indentationLevel));
         }
     }
 }

Tests/Rules/UseConsistentIndentation.tests.ps1

@@ -6,17 +6,19 @@ Import-Module (Join-Path $testRootDirectory "PSScriptAnalyzerTestHelper.psm1")
 
 $indentationUnit = ' '
 $indentationSize = 4
+$ruleConfiguration = @{
+    Enable          = $true
+    IndentationSize = 4
+    Kind            = 'space'
+}
+
 $settings = @{
     IncludeRules = @("PSUseConsistentIndentation")
-    Rules = @{
-        PSUseConsistentIndentation = @{
-            Enable = $true
-            IndentationSize = 4
-        }
+    Rules        = @{
+        PSUseConsistentIndentation = $ruleConfiguration
     }
 }
 
-
 Describe "UseConsistentIndentation" {
     Context "When top level indentation is not consistent" {
         BeforeAll {
@@ -127,17 +129,17 @@ function foo {
 get-process |
 where-object {$_.Name -match 'powershell'}
 '@
-          $violations = Invoke-ScriptAnalyzer -ScriptDefinition $def -Settings $settings
-          $violations.Count | Should Be 1
+            $violations = Invoke-ScriptAnalyzer -ScriptDefinition $def -Settings $settings
+            $violations.Count | Should Be 1
         }
 
         It "Should not find a violation if a pipleline element is indented correctly" {
             $def = @'
 get-process |
     where-object {$_.Name -match 'powershell'}
 '@
-          $violations = Invoke-ScriptAnalyzer -ScriptDefinition $def -Settings $settings
-          $violations.Count | Should Be 0
+            $violations = Invoke-ScriptAnalyzer -ScriptDefinition $def -Settings $settings
+            $violations.Count | Should Be 0
         }
 
         It "Should ignore comment in the pipleline" {
@@ -147,8 +149,8 @@ get-process |
 select Name,Id |
        format-list
 '@
-          $violations = Invoke-ScriptAnalyzer -ScriptDefinition $def -Settings $settings
-          $violations.Count | Should Be 3
+            $violations = Invoke-ScriptAnalyzer -ScriptDefinition $def -Settings $settings
+            $violations.Count | Should Be 3
         }
 
         It "Should indent properly after line continuation (backtick) character" {
@@ -159,13 +161,46 @@ $x = "this " + `
             $violations = Invoke-ScriptAnalyzer -ScriptDefinition $def -Settings $settings
             $violations.Count | Should Be 1
             $params = @{
-                RawContent = $def
+                RawContent       = $def
                 DiagnosticRecord = $violations[0]
                 CorrectionsCount = 1
-                ViolationText = "`"Should be indented properly`""
-                CorrectionText = (New-Object -TypeName String -ArgumentList $indentationUnit,$indentationSize) + "`"Should be indented properly`""
+                ViolationText    = "`"Should be indented properly`""
+                CorrectionText   = (New-Object -TypeName String -ArgumentList $indentationUnit, $indentationSize) + "`"Should be indented properly`""
             }
             Test-CorrectionExtentFromContent @params
         }
     }
+
+    Context "When tabs instead of spaces are used for indentation" {
+        BeforeAll {
+            $ruleConfiguration.'Kind' = 'tab'
+        }
+
+        It "Should indent using tabs" {
+            $def = @'
+function foo
+{
+get-childitem
+$x=1+2
+$hashtable = @{
+property1 = "value"
+    anotherProperty = "another value"
+}
+}
+'@
+            ${t} = "`t"
+            $expected = @"
+function foo
+{
+${t}get-childitem
+${t}`$x=1+2
+${t}`$hashtable = @{
+${t}${t}property1 = "value"
+${t}${t}anotherProperty = "another value"
+${t}}
+}
+"@
+            Invoke-Formatter -ScriptDefinition $def -Settings $settings | Should Be $expected
+        }
+    }
 }