Adjust --strict to treat warnings as errors instead of only altering exit code

CHANGELOG.md

@@ -2,7 +2,10 @@
 
 #### Breaking
 
-* None.
+* Changed behavior of `strict` option on `lint` and `analyze` to treat
+  all warnings as errors instead of only changing the exit code.  
+  [Jeehut](https://github.com/Jeehut)
+  [#3312](https://github.com/realm/SwiftLint/issues/3312)
 
 #### Experimental
 
@@ -200,11 +203,11 @@
   [Marcelo Fabri](https://github.com/marcelofabri)
   [#3225](https://github.com/realm/SwiftLint/issues/3225)
 
-* Fix some cases where the output would be incomplete when running 
+* Fix some cases where the output would be incomplete when running
   SwiftLint on Linux.  
   [Marcelo Fabri](https://github.com/marcelofabri)
   [#3214](https://github.com/realm/SwiftLint/issues/3214)
-  
+
 * `compiler_protocol_init` now triggers on `IndexSet(arrayLiteral:)`.  
   [Janak Shah](https://github.com/janakshah)
   [#3284](https://github.com/realm/SwiftLint/pull/3284)
@@ -244,7 +247,7 @@ This is the last release to support building with Swift 5.0.x.
   [Marcelo Fabri](https://github.com/marcelofabri)
   [#3149](https://github.com/realm/SwiftLint/issues/3149)
 
-* Fix false positives in `redundant_objc_attribute` rule in extensions when 
+* Fix false positives in `redundant_objc_attribute` rule in extensions when
   using Swift 5.2.  
   [Marcelo Fabri](https://github.com/marcelofabri)
 
@@ -371,7 +374,7 @@ This is the last release to support building with Swift 5.0.x.
 * Fix false positives when line ends with carriage return + line feed.  
   [John Mueller](https://github.com/john-mueller)
   [#3060](https://github.com/realm/SwiftLint/issues/3060)
-  
+
 * Implicit_return description now reports current config correctly.
   [John Buckley](https://github.com/nhojb)
 

Source/swiftlint/Commands/AnalyzeCommand.swift

@@ -69,7 +69,7 @@ struct AnalyzeOptions: OptionsProtocol {
             <*> mode <| pathOption(action: "analyze")
             <*> mode <| configOption
             <*> mode <| Option(key: "strict", defaultValue: false,
-                               usage: "fail on warnings")
+                               usage: "upgrades warnings to serious violations (errors)")
             <*> mode <| Option(key: "lenient", defaultValue: false,
                                usage: "downgrades serious violations to warnings, warning threshold is disabled")
             <*> mode <| Option(key: "force-exclude", defaultValue: false,

Source/swiftlint/Commands/LintCommand.swift

@@ -45,7 +45,7 @@ struct LintOptions: OptionsProtocol {
                                usage: "lint standard input")
             <*> mode <| configOption
             <*> mode <| Option(key: "strict", defaultValue: false,
-                               usage: "fail on warnings")
+                               usage: "upgrades warnings to serious violations (errors)")
             <*> mode <| Option(key: "lenient", defaultValue: false,
                                usage: "downgrades serious violations to warnings, warning threshold is disabled")
             <*> mode <| Option(key: "force-exclude", defaultValue: false,

Source/swiftlint/Helpers/LintOrAnalyzeCommand.swift

@@ -62,21 +62,11 @@ struct LintOrAnalyzeCommand {
                 ruleBenchmark.save()
             }
             try? cache?.save()
-            return successOrExit(numberOfSeriousViolations: numberOfSeriousViolations,
-                                 strictWithViolations: options.strict && !violations.isEmpty)
+            guard numberOfSeriousViolations == 0 else { exit(2) }
+            return .success(())
         }
     }
 
-    private static func successOrExit(numberOfSeriousViolations: Int,
-                                      strictWithViolations: Bool) -> Result<(), CommandantError<()>> {
-        if numberOfSeriousViolations > 0 {
-            exit(2)
-        } else if strictWithViolations {
-            exit(3)
-        }
-        return .success(())
-    }
-
     private static func printStatus(violations: [StyleViolation], files: [SwiftLintFile], serious: Int, verb: String) {
         let pluralSuffix = { (collection: [Any]) -> String in
             return collection.count != 1 ? "s" : ""
@@ -109,15 +99,30 @@ struct LintOrAnalyzeCommand {
     }
 
     private static func applyLeniency(options: LintOrAnalyzeOptions, violations: [StyleViolation]) -> [StyleViolation] {
-        if !options.lenient {
+        switch (options.lenient, options.strict) {
+        case (false, false):
             return violations
-        }
-        return violations.map {
-            if $0.severity == .error {
-                return $0.with(severity: .warning)
-            } else {
-                return $0
+
+        case (true, false):
+            return violations.map {
+                if $0.severity == .error {
+                    return $0.with(severity: .warning)
+                } else {
+                    return $0
+                }
             }
+
+        case (false, true):
+            return violations.map {
+                if $0.severity == .warning {
+                    return $0.with(severity: .error)
+                } else {
+                    return $0
+                }
+            }
+
+        case (true, true):
+            queuedFatalError("Invalid command line options: 'lenient' and 'strict' are mutually exclusive.")
         }
     }
 }