keep the original URL when decoding Download/ExternalLocationReference (

#621)

rdar://110536969

Sources/SwiftDocC/Model/Rendering/References/ExternalLocationReference.swift

@@ -24,7 +24,9 @@ public struct ExternalLocationReference: RenderReference, URLReference {
 
     public private(set) var type: RenderReferenceType = .externalLocation
 
-    public var identifier: RenderReferenceIdentifier
+    public let identifier: RenderReferenceIdentifier
+
+    let url: String
 
     enum CodingKeys: String, CodingKey {
         case type
@@ -34,21 +36,21 @@ public struct ExternalLocationReference: RenderReference, URLReference {
 
     public init(identifier: RenderReferenceIdentifier) {
         self.identifier = identifier
+        self.url = identifier.identifier
     }
 
     public init(from decoder: Decoder) throws {
         let container = try decoder.container(keyedBy: CodingKeys.self)
 
         self.identifier = try container.decode(RenderReferenceIdentifier.self, forKey: .identifier)
+        self.url = try container.decode(String.self, forKey: .url)
         self.type = try container.decode(RenderReferenceType.self, forKey: .type)
     }
 
     public func encode(to encoder: Encoder) throws {
         var container = encoder.container(keyedBy: CodingKeys.self)
         try container.encode(type.rawValue, forKey: .type)
         try container.encode(identifier, forKey: .identifier)
-
-        // Enter the given URL verbatim into the Render JSON
-        try container.encode(identifier.identifier, forKey: .url)
+        try container.encode(url, forKey: .url)
     }
 }

Sources/SwiftDocC/Model/Rendering/Tutorial/References/DownloadReference.swift

@@ -26,7 +26,15 @@ public struct DownloadReference: RenderReference, URLReference, Equatable {
 
     /// The location of the downloadable resource.
     public var url: URL
-
+
+    /// Indicates whether the ``url`` property was loaded from the regular initializer or from the
+    /// `Decodable` initializer.
+    ///
+    /// This is used during encoding to determine whether to filter ``url`` through the
+    /// `renderURL(for:)` method. In case the URL was loaded from JSON, we don't want to modify it
+    /// further after a round-trip.
+    private var urlWasDecoded = false
+
     /// The SHA512 hash value for the resource.
     public var checksum: String?
 
@@ -60,15 +68,41 @@ public struct DownloadReference: RenderReference, URLReference, Equatable {
     public init(identifier: RenderReferenceIdentifier, renderURL url: URL, sha512Checksum: String) {
         self.init(identifier: identifier, renderURL: url, checksum: sha512Checksum)
     }
-
+
+    enum CodingKeys: CodingKey {
+        case type
+        case identifier
+        case url
+        case checksum
+    }
+
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+        self.type = try container.decode(RenderReferenceType.self, forKey: .type)
+        self.identifier = try container.decode(RenderReferenceIdentifier.self, forKey: .identifier)
+        self.url = try container.decode(URL.self, forKey: .url)
+        self.urlWasDecoded = true
+        self.checksum = try container.decodeIfPresent(String.self, forKey: .checksum)
+    }
+
     public func encode(to encoder: Encoder) throws {
         var container = encoder.container(keyedBy: CodingKeys.self)
         try container.encode(type.rawValue, forKey: .type)
         try container.encode(identifier, forKey: .identifier)
         try container.encodeIfPresent(checksum, forKey: .checksum)
 
         // Render URL
-        try container.encode(renderURL(for: url), forKey: .url)
+        if !urlWasDecoded {
+            try container.encode(renderURL(for: url), forKey: .url)
+        } else {
+            try container.encode(url, forKey: .url)
+        }
+    }
+
+    static public func ==(lhs: DownloadReference, rhs: DownloadReference) -> Bool {
+        lhs.identifier == rhs.identifier
+        && lhs.url == rhs.url
+        && lhs.checksum == rhs.checksum
     }
 }
 

Tests/SwiftDocCTests/Rendering/Rendering Fixtures/external-location-custom-url.json

@@ -0,0 +1,110 @@
+{
+  "schemaVersion" : {
+    "major" : 1,
+    "minor" : 0,
+    "patch" : 0
+  },
+  "seeAlsoSections" : [ ],
+  "metadata" : {
+    "platforms" : [
+      {
+        "name" : "macOS",
+        "introducedAt" : "10.15"
+      }
+    ],
+    "modules" : [
+      { "name" : "MyKit" }
+    ],
+    "title" : "Wifi Access",
+    "roleHeading" : "Plist Key"
+  },
+  "abstract" : [
+    {
+      "type" : "text",
+      "text" : "A "
+    },
+    {
+      "type" : "codeVoice",
+      "code" : "WiFi access"
+    },
+    {
+      "type" : "text",
+      "text" : " abstract description."
+    }
+  ],
+  "sections" : [
+  ],
+  "identifier" : {
+      "url" : "doc:\/\/org.swift.docc.example\/plist\/wifiaccess",
+      "interfaceLanguage": "swift"
+  },
+  "hierarchy" : {
+    "paths" : [["doc:\/\/org.swift.docc.example\/plist\/wifiaccess"]]
+  },
+  "topicSections" : [
+  ],
+  "kind" : "symbol",
+  "references" : {
+    "doc:\/\/org.swift.docc.example\/downloads\/sample.zip": {
+      "identifier": "ExternalLocation.zip",
+      "url": "https://example.com/ExternalLocation.zip",
+      "type": "externalLocation"
+    },
+    "doc:\/\/org.swift.docc.example\/plist\/wifiaccess": {
+      "abstract" : [
+        {
+          "text" : "WiFi access",
+          "type" : "text"
+        }
+      ],
+      "identifier" : "doc:\/\/org.swift.docc.example\/plist\/wifiaccess",
+      "kind" : "symbol",
+      "title" : "WiFi Access",
+      "type" : "topic",
+      "url" : "\/documentation\/mykit"
+    }
+  },
+  "sampleCodeDownload": {
+      "action": {
+          "identifier": "doc:\/\/org.swift.docc.example\/downloads\/sample.zip",
+          "isActive": true,
+          "overridingTitle": "Download",
+          "type": "reference"
+      }
+  },
+  "primaryContentSections" : [
+    {
+      "kind" : "content",
+      "content" : [
+        {
+          "anchor" : "discussion",
+          "level" : 2,
+          "type" : "heading",
+          "text" : "Discussion"
+        },
+        {
+          "type" : "paragraph",
+          "inlineContent" : [
+            {
+              "type" : "text",
+              "text" : "Use "
+            },
+            {
+              "type" : "codeVoice",
+              "code" : "Wifi access"
+            },
+            {
+              "type" : "text",
+              "text" : " to secure wifi access for your app."
+            }
+          ]
+        }
+      ]
+    }
+  ],
+  "variants": [{
+      "paths" : ["\/plist\/wifiaccess"],
+      "traits" : []
+  }]
+}
+

Tests/SwiftDocCTests/Rendering/SampleDownloadTests.swift

@@ -240,4 +240,55 @@ class SampleDownloadTests: XCTestCase {
         let reference = try XCTUnwrap(renderNode.references[identifier.identifier])
         XCTAssert(reference is ExternalLocationReference)
     }
+
+    /// Ensure that a DownloadReference where the URL is different from the reference identifier
+    /// can still round-trip through an ExternalLocationReference with the URL and reference identifier intact.
+    func testRoundTripWithDifferentUrl() throws {
+        let baseReference = DownloadReference(identifier: .init("DownloadReference.zip"), renderURL: .init(string: "https://example.com/DownloadReference.zip")!, checksum: nil)
+
+        let encoder = JSONEncoder()
+        let decoder = JSONDecoder()
+
+        let encodedReference = try encoder.encode(baseReference)
+
+        let interimReference = try decoder.decode(ExternalLocationReference.self, from: encodedReference)
+        let interimEncodedReference = try encoder.encode(interimReference)
+
+        let roundTripReference = try decoder.decode(DownloadReference.self, from: interimEncodedReference)
+
+        XCTAssertEqual(baseReference, roundTripReference)
+    }
+
+    /// Ensure that an ExternalLocationReference loaded from JSON continues to encode the same
+    /// information after being decoded and re-encoded.
+    func testRoundTripExternalLocationFromFixture() throws {
+        let downloadSymbolURL = Bundle.module.url(
+            forResource: "external-location-custom-url", withExtension: "json",
+            subdirectory: "Rendering Fixtures")!
+
+        let originalData = try Data(contentsOf: downloadSymbolURL)
+        let originalRenderNode = try RenderNode.decode(fromJSON: originalData)
+
+        let encodedRenderNode = try JSONEncoder().encode(originalRenderNode)
+        let symbol = try RenderNode.decode(fromJSON: encodedRenderNode)
+
+        //
+        // Sample Download Details
+        //
+
+        guard let section = symbol.sampleDownload else {
+            XCTFail("Download section not decoded")
+            return
+        }
+
+        guard case RenderInlineContent.reference(let identifier, _, _, _) = section.action else {
+            XCTFail("Could not decode action reference")
+            return
+        }
+
+        XCTAssertEqual(identifier.identifier, "doc://org.swift.docc.example/downloads/sample.zip")
+
+        let externalReference = try XCTUnwrap(symbol.references[identifier.identifier] as? ExternalLocationReference)
+        XCTAssertEqual(externalReference.url, "https://example.com/ExternalLocation.zip")
+    }
 }