Add `include_multiline_strings` option to `indentation_width` rule (#4785)

CHANGELOG.md

@@ -24,7 +24,7 @@
 
 * Make forceExclude work with directly specified files.  
   [jimmya](https://github.com/jimmya)
-  [#issue_number](https://github.com/realm/SwiftLint/issues/4609)
+  [#4609](https://github.com/realm/SwiftLint/issues/4609)
 
 * Separate analyzer rules as an independent section in the rule directory of
   the reference.  
@@ -87,6 +87,10 @@
   [Martin Redington](https://github.com/mildm8nnered)
   [#4767](https://github.com/realm/SwiftLint/issues/4767)
 
+* Adds `include_multiline_strings` option to `indentation_width` rule.  
+  [Martin Redington](https://github.com/mildm8nnered)
+  [#4248](https://github.com/realm/SwiftLint/issues/4248)
+
 #### Bug Fixes
 
 * Report violations in all `<scope>_length` rules when the error threshold is

Source/SwiftLintFramework/Rules/RuleConfigurations/IndentationWidthConfiguration.swift

@@ -4,23 +4,27 @@ struct IndentationWidthConfiguration: RuleConfiguration, Equatable {
             + "indentation_width: \(indentationWidth), "
             + "include_comments: \(includeComments), "
             + "include_compiler_directives: \(includeCompilerDirectives)"
+            + "include_multiline_strings: \(includeMultilineStrings)"
     }
 
     private(set) var severityConfiguration: SeverityConfiguration
     private(set) var indentationWidth: Int
     private(set) var includeComments: Bool
     private(set) var includeCompilerDirectives: Bool
+    private(set) var includeMultilineStrings: Bool
 
     init(
         severity: ViolationSeverity,
         indentationWidth: Int,
         includeComments: Bool,
-        includeCompilerDirectives: Bool
+        includeCompilerDirectives: Bool,
+        includeMultilineStrings: Bool
     ) {
         self.severityConfiguration = SeverityConfiguration(severity)
         self.indentationWidth = indentationWidth
         self.includeComments = includeComments
         self.includeCompilerDirectives = includeCompilerDirectives
+        self.includeMultilineStrings = includeMultilineStrings
     }
 
     mutating func apply(configuration: Any) throws {
@@ -43,5 +47,9 @@ struct IndentationWidthConfiguration: RuleConfiguration, Equatable {
         if let includeCompilerDirectives = configurationDict["include_compiler_directives"] as? Bool {
             self.includeCompilerDirectives = includeCompilerDirectives
         }
+
+        if let includeMultilineStrings = configurationDict["include_multiline_strings"] as? Bool {
+            self.includeMultilineStrings = includeMultilineStrings
+        }
     }
 }

Source/SwiftLintFramework/Rules/Style/IndentationWidthRule.swift

@@ -20,7 +20,8 @@ struct IndentationWidthRule: ConfigurationProviderRule, OptInRule {
         severity: .warning,
         indentationWidth: 4,
         includeComments: true,
-        includeCompilerDirectives: true
+        includeCompilerDirectives: true,
+        includeMultilineStrings: true
     )
     static let description = RuleDescription(
         identifier: "indentation_width",
@@ -58,7 +59,7 @@ struct IndentationWidthRule: ConfigurationProviderRule, OptInRule {
             let indentationCharacterCount = line.content.countOfLeadingCharacters(in: CharacterSet(charactersIn: " \t"))
             if line.content.count == indentationCharacterCount { continue }
 
-            if ignoreComment(line: line, in: file) { continue }
+            if ignoreComment(line: line, in: file) || ignoreMultilineStrings(line: line, in: file) { continue }
 
             // Get space and tab count in prefix
             let prefix = String(line.content.prefix(indentationCharacterCount))
@@ -167,6 +168,16 @@ struct IndentationWidthRule: ConfigurationProviderRule, OptInRule {
         return false
     }
 
+    private func ignoreMultilineStrings(line: Line, in file: SwiftLintFile) -> Bool {
+        if configuration.includeMultilineStrings {
+            return false
+        }
+        if file.syntaxMap.tokens(inByteRange: line.byteRange).kinds == [.string] {
+            return true
+        }
+        return false
+    }
+
     /// Validates whether the indentation of a specific line is valid based on the indentation of the previous line.
     ///
     /// - parameter indentation:     The indentation of the line to validate.

Tests/SwiftLintFrameworkTests/IndentationWidthRuleTests.swift

@@ -196,12 +196,27 @@ class IndentationWidthRuleTests: XCTestCase {
             """, includeCompilerDirectives: true)
     }
 
+    func testIgnoredMultilineStrings() {
+        assertNoViolation(
+            in: "let x = \"\"\"\nstring1\n    string2\n  string3\n\"\"\"\n",
+            includeMultilineStrings: false
+        )
+        assert1Violation(
+            in: "let x = \"\"\"\nstring1\n    string2\n  string3\n\"\"\"\n"
+        )
+        assertViolations(
+            in: "let x = \"\"\"\nstring1\n    string2\n  string3\n string4\n\"\"\"\n",
+            equals: 2
+        )
+    }
+
     // MARK: Helpers
     private func countViolations(
         in example: Example,
         indentationWidth: Int? = nil,
         includeComments: Bool? = nil,
         includeCompilerDirectives: Bool? = nil,
+        includeMultilineStrings: Bool? = nil,
         file: StaticString = #file,
         line: UInt = #line
     ) -> Int {
@@ -215,6 +230,9 @@ class IndentationWidthRuleTests: XCTestCase {
         if let includeCompilerDirectives {
             configDict["include_compiler_directives"] = includeCompilerDirectives
         }
+        if let includeMultilineStrings {
+            configDict["include_multiline_strings"] = includeMultilineStrings
+        }
 
         guard let config = makeConfig(configDict, IndentationWidthRule.description.identifier) else {
             XCTFail("Unable to create rule configuration.", file: (file), line: line)
@@ -230,6 +248,7 @@ class IndentationWidthRuleTests: XCTestCase {
         indentationWidth: Int? = nil,
         includeComments: Bool? = nil,
         includeCompilerDirectives: Bool? = nil,
+        includeMultilineStrings: Bool? = nil,
         file: StaticString = #file,
         line: UInt = #line
     ) {
@@ -239,6 +258,7 @@ class IndentationWidthRuleTests: XCTestCase {
                 indentationWidth: indentationWidth,
                 includeComments: includeComments,
                 includeCompilerDirectives: includeCompilerDirectives,
+                includeMultilineStrings: includeMultilineStrings,
                 file: file,
                 line: line
             ),
@@ -253,6 +273,7 @@ class IndentationWidthRuleTests: XCTestCase {
         indentationWidth: Int? = nil,
         includeComments: Bool? = nil,
         includeCompilerDirectives: Bool? = nil,
+        includeMultilineStrings: Bool? = nil,
         file: StaticString = #file,
         line: UInt = #line
     ) {
@@ -262,6 +283,7 @@ class IndentationWidthRuleTests: XCTestCase {
             indentationWidth: indentationWidth,
             includeComments: includeComments,
             includeCompilerDirectives: includeCompilerDirectives,
+            includeMultilineStrings: includeMultilineStrings,
             file: file,
             line: line
         )
@@ -272,6 +294,7 @@ class IndentationWidthRuleTests: XCTestCase {
         indentationWidth: Int? = nil,
         includeComments: Bool? = nil,
         includeCompilerDirectives: Bool? = nil,
+        includeMultilineStrings: Bool? = nil,
         file: StaticString = #file,
         line: UInt = #line
     ) {
@@ -281,6 +304,7 @@ class IndentationWidthRuleTests: XCTestCase {
             indentationWidth: indentationWidth,
             includeComments: includeComments,
             includeCompilerDirectives: includeCompilerDirectives,
+            includeMultilineStrings: includeMultilineStrings,
             file: file,
             line: line
         )