From af743ad6882bfe1adb0acf7453d36d2075ebb1d5 Mon Sep 17 00:00:00 2001
From: Ezekiel Elin <ezekielelin@me.com>
Date: Fri, 29 Nov 2019 17:37:51 -0500
Subject: [PATCH] Introduce case-insensitivity for reference link labels (#16)

Merge PR from @ezfe
* Introduce case-insensitivity for reference link labels
* Moved `.lowercased()`
---
 Sources/Ink/API/MarkdownParser.swift          |  2 +-
 Sources/Ink/Internal/NamedURLCollection.swift |  6 +++---
 Sources/Ink/Internal/URLDeclaration.swift     |  4 ++--
 Tests/InkTests/LinkTests.swift                | 13 +++++++++++++
 4 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/Sources/Ink/API/MarkdownParser.swift b/Sources/Ink/API/MarkdownParser.swift
index 2bbb6de..c9a0516 100644
--- a/Sources/Ink/API/MarkdownParser.swift
+++ b/Sources/Ink/API/MarkdownParser.swift
@@ -42,7 +42,7 @@ public struct MarkdownParser {
     public func parse(_ markdown: String) -> Markdown {
         var reader = Reader(string: markdown)
         var fragments = [ParsedFragment]()
-        var urlsByName = [Substring : URL]()
+        var urlsByName = [String : URL]()
         var metadata: Metadata?
 
         while !reader.didReachEnd {
diff --git a/Sources/Ink/Internal/NamedURLCollection.swift b/Sources/Ink/Internal/NamedURLCollection.swift
index a0391a9..ce0c1fe 100644
--- a/Sources/Ink/Internal/NamedURLCollection.swift
+++ b/Sources/Ink/Internal/NamedURLCollection.swift
@@ -5,13 +5,13 @@
 */
 
 internal struct NamedURLCollection {
-    private let urlsByName: [Substring : URL]
+    private let urlsByName: [String : URL]
 
-    init(urlsByName: [Substring : URL]) {
+    init(urlsByName: [String : URL]) {
         self.urlsByName = urlsByName
     }
 
     func url(named name: Substring) -> URL? {
-        urlsByName[name]
+        urlsByName[name.lowercased()]
     }
 }
diff --git a/Sources/Ink/Internal/URLDeclaration.swift b/Sources/Ink/Internal/URLDeclaration.swift
index 188b06b..1dfd34f 100644
--- a/Sources/Ink/Internal/URLDeclaration.swift
+++ b/Sources/Ink/Internal/URLDeclaration.swift
@@ -5,7 +5,7 @@
 */
 
 internal struct URLDeclaration: Readable {
-    var name: Substring
+    var name: String
     var url: URL
 
     static func read(using reader: inout Reader) throws -> Self {
@@ -15,6 +15,6 @@ internal struct URLDeclaration: Readable {
         try reader.readWhitespaces()
         let url = reader.readUntilEndOfLine()
 
-        return URLDeclaration(name: name, url: url)
+        return URLDeclaration(name: name.lowercased(), url: url)
     }
 }
diff --git a/Tests/InkTests/LinkTests.swift b/Tests/InkTests/LinkTests.swift
index 15bffca..6605e10 100644
--- a/Tests/InkTests/LinkTests.swift
+++ b/Tests/InkTests/LinkTests.swift
@@ -23,6 +23,18 @@ final class LinkTests: XCTestCase {
         XCTAssertEqual(html, #"<p><a href="swiftbysundell.com">Title</a></p>"#)
     }
 
+    func testCaseMismatchedLinkWithReference() {
+        let html = MarkdownParser().html(from: """
+        [Title][Foo]
+        [Title][αγω]
+
+        [FOO]: /url
+        [ΑΓΩ]: /φου
+        """)
+
+        XCTAssertEqual(html, #"<p><a href="/url">Title</a> <a href="/φου">Title</a></p>"#)
+    }
+
     func testNumericLinkWithReference() {
         let html = MarkdownParser().html(from: """
         [1][1]
@@ -59,6 +71,7 @@ extension LinkTests {
         return [
             ("testLinkWithURL", testLinkWithURL),
             ("testLinkWithReference", testLinkWithReference),
+            ("testCaseMismatchedLinkWithReference", testCaseMismatchedLinkWithReference),
             ("testNumericLinkWithReference", testNumericLinkWithReference),
             ("testBoldLinkWithInternalMarkers", testBoldLinkWithInternalMarkers),
             ("testBoldLinkWithExternalMarkers", testBoldLinkWithExternalMarkers),