[MBL-19470][S/T/P] Fixes issue of un-viewable file upload submissions for assignments with moderated grading

Core/Core/Common/CommonModels/API/APIURL.swift

@@ -33,7 +33,9 @@ public struct APIURL: Codable, Equatable {
     public init(from decoder: Decoder) throws {
         let baseURL = AppEnvironment.shared.currentSession?.baseURL
         let container = try decoder.singleValueContainer()
-        let string = try container.decode(String.self).removingXMLEscaping
+        let string = try container.decode(String.self)
+            .removingXMLEscaping
+            .removingQueryPercentEncoding
         if let url = URL(string: string, relativeTo: baseURL) {
             rawValue = url
             return
@@ -69,6 +71,28 @@ extension KeyedDecodingContainer {
     }
 }
 
+private extension String {
+
+    /// Keeping this private as it aims to fix a specific issue with URL strings
+    /// retrieved from BackEnd: Such strings get percent-encoded except for brackets
+    /// characters `[` & `]` in query part. Thus resulting into double encoding for some
+    /// other characters when fed to `URL.init(string:)` leading to failure on request.
+    ///
+    /// This method removes percent-encoding entirely for the query part, so
+    /// it get encoded properly as a whole when using `URL.init(string:)` with
+    /// the resulting one. It assumes Backend perform only 1 iteration of
+    /// percent-encoding on URL strings.
+    var removingQueryPercentEncoding: String {
+        if var comps = URLComponents(string: self) {
+            if let fixedQuery = comps.query?.removingPercentEncoding {
+                comps.query = fixedQuery
+            }
+            return comps.string ?? self
+        }
+        return self
+    }
+}
+
 #if DEBUG
 extension APIURL {
     public static func make(

Core/CoreTests/Common/CommonModels/API/APIURLTests.swift

@@ -90,6 +90,33 @@ class APIURLTests: CoreTestCase {
         let model = try decoder.decode(MockAPIResponse.self, from: data)
         XCTAssertEqual(model.avatar_url?.rawValue, URL(string: "https://example.com/path%7B%20%7D%60%7C%5C%5E")!)
     }
+
+    func testURLQueryPercentEncoding() throws {
+        XCTAssertEqual(
+            try decoder.decode(APIURL.self, from: try encoder.encode("https://domain.com?q=value")),
+            .make(rawValue: URL(string: "https://domain.com?q=value")!)
+        )
+
+        XCTAssertEqual(
+            try decoder.decode(APIURL.self, from: try encoder.encode("https://domain.com?q=some value")),
+            .make(rawValue: URL(string: "https://domain.com?q=some%20value")!)
+        )
+
+        XCTAssertEqual(
+            try decoder.decode(APIURL.self, from: try encoder.encode("https://domain.com?q=[some value]")),
+            .make(rawValue: URL(string: "https://domain.com?q=%5Bsome%20value%5D")!)
+        )
+
+        XCTAssertEqual(
+            try decoder.decode(APIURL.self, from: try encoder.encode("https://domain.com?q=[some%20value]")),
+            .make(rawValue: URL(string: "https://domain.com?q=%5Bsome%20value%5D")!)
+        )
+
+        XCTAssertEqual(
+            try decoder.decode(APIURL.self, from: try encoder.encode("https://domain.com?q=[some value]&a=another%20value")),
+            .make(rawValue: URL(string: "https://domain.com?q=%5Bsome%20value%5D&a=another%20value")!)
+        )
+    }
 }
 
 private struct MockAPIResponse: Codable {