Add experimental code block options: highlight, strikeout, wrap, showLineNumbers

Sources/SwiftDocC/Checker/Checkers/InvalidCodeBlockOption.swift

@@ -0,0 +1,97 @@
+/*
+ This source file is part of the Swift.org open source project
+
+ Copyright (c) 2025 Apple Inc. and the Swift project authors
+ Licensed under Apache License v2.0 with Runtime Library Exception
+
+ See https://swift.org/LICENSE.txt for license information
+ See https://swift.org/CONTRIBUTORS.txt for Swift project authors
+*/
+
+internal import Foundation
+internal import Markdown
+
+/**
+ Code blocks can have a `nocopy` option after the \`\`\`, in the language line.
+`nocopy` can be immediately after the \`\`\` or after a specified language and a comma (`,`).
+ */
+internal struct InvalidCodeBlockOption: Checker {
+    var problems = [Problem]()
+
+    /// Parsing options for code blocks
+    private let knownOptions = RenderBlockContent.CodeBlockOptions.knownOptions
+
+    private var sourceFile: URL?
+
+    /// Creates a new checker that detects documents with multiple titles.
+    ///
+    /// - Parameter sourceFile: The URL to the documentation file that the checker checks.
+    init(sourceFile: URL?) {
+        self.sourceFile = sourceFile
+    }
+
+    mutating func visitCodeBlock(_ codeBlock: CodeBlock) {
+        let (lang, tokens) = RenderBlockContent.CodeBlockOptions.tokenizeLanguageString(codeBlock.language)
+
+        func matches(token: RenderBlockContent.CodeBlockOptions.OptionName, value: String?) {
+            guard token == .unknown, let value = value else { return }
+
+            let matches = NearMiss.bestMatches(for: knownOptions, against: value)
+
+            if !matches.isEmpty {
+                let diagnostic = Diagnostic(source: sourceFile, severity: .warning, range: codeBlock.range, identifier: "org.swift.docc.InvalidCodeBlockOption", summary: "Unknown option \(value.singleQuoted) in code block.")
+                let possibleSolutions = matches.map { candidate in
+                    Solution(
+                        summary: "Replace \(value.singleQuoted) with \(candidate.singleQuoted).",
+                        replacements: []
+                    )
+                }
+                problems.append(Problem(diagnostic: diagnostic, possibleSolutions: possibleSolutions))
+            } else if lang == nil {
+                let diagnostic = Diagnostic(source: sourceFile, severity: .warning, range: codeBlock.range, identifier: "org.swift.docc.InvalidCodeBlockOption", summary: "Unknown option \(value.singleQuoted) in code block.")
+                let possibleSolutions =
+                Solution(
+                    summary: "If \(value.singleQuoted) is the language for this code block, then write \(value.singleQuoted) as the first option.",
+                    replacements: []
+                )
+                problems.append(Problem(diagnostic: diagnostic, possibleSolutions: [possibleSolutions]))
+            }
+        }
+
+        func validateArrayIndices(token: RenderBlockContent.CodeBlockOptions.OptionName, value: String?) {
+            guard token == .highlight || token == .strikeout, let value = value else { return }
+            // code property ends in a newline. this gives us a bogus extra line.
+            let lineCount: Int = codeBlock.code.split(omittingEmptySubsequences: false, whereSeparator: { $0.isNewline }).count - 1
+
+            let indices = RenderBlockContent.CodeBlockOptions.parseCodeBlockOptionsArray(value)
+
+            if !value.isEmpty, indices.isEmpty {
+                let diagnostic = Diagnostic(source: sourceFile, severity: .warning, range: codeBlock.range, identifier: "org.swift.docc.InvalidCodeBlockOption", summary: "Could not parse \(token.rawValue.singleQuoted) indices from \(value.singleQuoted). Expected an integer (e.g. 3) or an array (e.g. [1, 3, 5])")
+                problems.append(Problem(diagnostic: diagnostic, possibleSolutions: []))
+                return
+            }
+
+            let invalid = indices.filter { $0 < 1 || $0 > lineCount }
+            guard !invalid.isEmpty else { return }
+
+            let diagnostic = Diagnostic(source: sourceFile, severity: .warning, range: codeBlock.range, identifier: "org.swift.docc.InvalidCodeBlockOption", summary: "Invalid \(token.rawValue.singleQuoted) index\(invalid.count == 1 ? "" : "es") in \(value.singleQuoted) for a code block with \(lineCount) line\(lineCount == 1 ? "" : "s"). Valid range is 1...\(lineCount).")
+            let solutions: [Solution] = {
+                if invalid.contains(where: {$0 == lineCount + 1}) {
+                    return [Solution(
+                        summary: "If you intended the last line, change '\(lineCount + 1)' to \(lineCount).",
+                        replacements: []
+                    )]
+                }
+                return []
+            }()
+            problems.append(Problem(diagnostic: diagnostic, possibleSolutions: solutions))
+        }
+
+        for (token, value) in tokens {
+            matches(token: token, value: value)
+            validateArrayIndices(token: token, value: value)
+        }
+        // check if first token (lang) might be a typo
+        matches(token: .unknown, value: lang)
+    }
+}

Sources/SwiftDocC/Infrastructure/DocumentationContext.swift

@@ -271,6 +271,7 @@ public class DocumentationContext {
             MissingAbstract(sourceFile: source).any(),
             NonOverviewHeadingChecker(sourceFile: source).any(),
             SeeAlsoInTopicsHeadingChecker(sourceFile: source).any(),
+            InvalidCodeBlockOption(sourceFile: source).any(),
         ])
         checker.visit(document)
         diagnosticEngine.emit(checker.problems)
@@ -2453,7 +2454,6 @@ public class DocumentationContext {
             }
         }
     }
-
     /// A closure type getting the information about a reference in a context and returns any possible problems with it.
     public typealias ReferenceCheck = (DocumentationContext, ResolvedTopicReference) -> [Problem]
 

Sources/SwiftDocC/Infrastructure/Workspace/FeatureFlags+Info.swift

@@ -37,11 +37,20 @@ extension DocumentationBundle.Info {
             self.unknownFeatureFlags = []
         }
 
+        /// This feature flag corresponds to ``FeatureFlags/isExperimentalCodeBlockAnnotationsEnabled``.
+        public var experimentalCodeBlockAnnotations: Bool?
+
+        public init(experimentalCodeBlockAnnotations: Bool? = nil) {
+            self.experimentalCodeBlockAnnotations = experimentalCodeBlockAnnotations
+            self.unknownFeatureFlags = []
+        }
+
         /// A list of decoded feature flag keys that didn't match a known feature flag.
         public let unknownFeatureFlags: [String]
 
         enum CodingKeys: String, CodingKey, CaseIterable {
             case experimentalOverloadedSymbolPresentation = "ExperimentalOverloadedSymbolPresentation"
+            case experimentalCodeBlockAnnotations = "ExperimentalCodeBlockAnnotations"
         }
 
         struct AnyCodingKeys: CodingKey {
@@ -66,6 +75,9 @@ extension DocumentationBundle.Info {
                     switch codingKey {
                     case .experimentalOverloadedSymbolPresentation:
                         self.experimentalOverloadedSymbolPresentation = try values.decode(Bool.self, forKey: flagName)
+
+                    case .experimentalCodeBlockAnnotations:
+                        self.experimentalCodeBlockAnnotations = try values.decode(Bool.self, forKey: flagName)
                     }
                 } else {
                     unknownFeatureFlags.append(flagName.stringValue)
@@ -79,6 +91,7 @@ extension DocumentationBundle.Info {
             var container = encoder.container(keyedBy: CodingKeys.self)
 
             try container.encode(experimentalOverloadedSymbolPresentation, forKey: .experimentalOverloadedSymbolPresentation)
+            try container.encode(experimentalCodeBlockAnnotations, forKey: .experimentalCodeBlockAnnotations)
         }
     }
 }