add method to BasicBlockContainer that inherits the source ranges

Author: QuietMisdreavus

Sources/Markdown/Base/Document.swift

@@ -66,7 +66,13 @@ public extension Document {
 
     /// Create a document from a sequence of block markup elements.
     init<Children: Sequence>(_ children: Children) where Children.Element == BlockMarkup {
-        try! self.init(.document(parsedRange: nil, children.map { $0.raw.markup }))
+        self.init(children, inheritSourceRange: false)
+    }
+
+    init<Children: Sequence>(_ children: Children, inheritSourceRange: Bool) where Children.Element == BlockMarkup {
+        let rawChildren = children.map { $0.raw.markup }
+        let parsedRange = inheritSourceRange ? rawChildren.parsedRange : nil
+        try! self.init(.document(parsedRange: parsedRange, rawChildren))
     }
 
     // MARK: Visitation

Sources/Markdown/Base/RawMarkup.swift

@@ -366,3 +366,13 @@ fileprivate extension Sequence where Element == RawMarkup {
         return self.lazy.map { $0.subtreeCount }.reduce(0, +)
     }
 }
+
+extension BidirectionalCollection where Element == RawMarkup {
+    var parsedRange: SourceRange? {
+        if let lowerBound = first?.parsedRange?.lowerBound, let upperBound = last?.parsedRange?.upperBound {
+            return lowerBound..<upperBound
+        } else {
+            return nil
+        }
+    }
+}

Sources/Markdown/Block Nodes/Block Container Blocks/BlockQuote.swift

@@ -30,7 +30,13 @@ public extension BlockQuote {
     // MARK: BasicBlockContainer
 
     init<Children: Sequence>(_ children: Children) where Children.Element == BlockMarkup {
-        try! self.init(.blockQuote(parsedRange: nil, children.map { $0.raw.markup }))
+        self.init(children, inheritSourceRange: false)
+    }
+
+    init<Children: Sequence>(_ children: Children, inheritSourceRange: Bool) where Children.Element == BlockMarkup {
+        let rawChildren = children.map { $0.raw.markup }
+        let parsedRange = inheritSourceRange ? rawChildren.parsedRange : nil
+        try! self.init(.blockQuote(parsedRange: parsedRange, rawChildren))
     }
 
     // MARK: Visitation

Sources/Markdown/Block Nodes/Block Container Blocks/CustomBlock.swift

@@ -30,7 +30,13 @@ public struct CustomBlock: BlockMarkup, BasicBlockContainer {
 
 public extension CustomBlock {
     init<Children: Sequence>(_ children: Children) where Children.Element == BlockMarkup {
-        try! self.init(.customBlock(parsedRange: nil, children.map { $0.raw.markup }))
+        self.init(children, inheritSourceRange: false)
+    }
+
+    init<Children: Sequence>(_ children: Children, inheritSourceRange: Bool) where Children.Element == BlockMarkup {
+        let rawChildren = children.map { $0.raw.markup }
+        let parsedRange = inheritSourceRange ? rawChildren.parsedRange : nil
+        try! self.init(.customBlock(parsedRange: parsedRange, rawChildren))
     }
 
     // MARK: Visitation

Sources/Markdown/Structural Restrictions/BasicBlockContainer.swift

@@ -12,6 +12,9 @@
 public protocol BasicBlockContainer: BlockContainer {
     /// Create this element from a sequence of block markup elements.
     init<Children: Sequence>(_ children: Children) where Children.Element == BlockMarkup
+
+    /// Create this element from a sequence of block markup elements, and optionally inherit the source range from those elements.
+    init<Children: Sequence>(_ children: Children, inheritSourceRange: Bool) where Children.Element == BlockMarkup
 }
 
 // MARK: - Public API
@@ -21,4 +24,14 @@ extension BasicBlockContainer {
     public init(_ children: BlockMarkup...) {
         self.init(children)
     }
+
+    /// Create this element with a sequence of block markup elements, and optionally inherit the source range from those elements.
+    public init(_ children: BlockMarkup..., inheritSourceRange: Bool) {
+        self.init(children, inheritSourceRange: inheritSourceRange)
+    }
+
+    /// Default implementation of `init(_:inheritSourceRange:)` that discards the `inheritSourceRange` parameter.
+    public init<Children: Sequence>(_ children: Children, inheritSourceRange: Bool) where Children.Element == BlockMarkup {
+        self.init(children)
+    }
 }

Tests/MarkdownTests/Structural Restrictions/BasicBlockContainerTests.swift

@@ -110,4 +110,22 @@ final class BasicBlockContainerTests: XCTestCase {
             """
         XCTAssertEqual(expectedDump, newDocument.debugDescription())
     }
+
+    func testInheritSourceRange() throws {
+        let source = "Note: This is just a paragraph."
+        let fakeFileLocation = URL(fileURLWithPath: "/path/to/some-file.md")
+        let document = Document(parsing: source, source: fakeFileLocation)
+        let paragraph = try XCTUnwrap(document.child(at: 0) as? Paragraph)
+
+        // this block quote has no source information, but its children do
+        let blockQuote = BlockQuote(paragraph, inheritSourceRange: true)
+
+        let expectedRootDump = """
+        BlockQuote @/path/to/some-file.md:1:1-/path/to/some-file.md:1:32
+        └─ Paragraph @/path/to/some-file.md:1:1-/path/to/some-file.md:1:32
+           └─ Text @/path/to/some-file.md:1:1-/path/to/some-file.md:1:32 "Note: This is just a paragraph."
+        """
+
+        XCTAssertEqual(expectedRootDump, blockQuote.debugDescription(options: .printSourceLocations))
+    }
 }