Merge pull request #505 from Esri/Ting/FixStringLinterWarnings

[Update] Fix linter warnings for string <-> data conversion

Scripts/DowloadPortalItemData.swift

@@ -87,7 +87,7 @@ func name(ofFileInArchiveAt url: URL) throws -> String {
     process.waitUntilExit()
 
     let filenameData = outputPipe.fileHandleForReading.readDataToEndOfFile()
-    return String(data: filenameData, encoding: .utf8)!.trimmingCharacters(in: .whitespacesAndNewlines)
+    return String(decoding: filenameData, as: UTF8.self).trimmingCharacters(in: .whitespacesAndNewlines)
 }
 
 /// Counts files in a ZIP archive.
@@ -108,7 +108,7 @@ func count(ofFilesInArchiveAt url: URL) throws -> Int {
     // To extract the count, cut the string at the first whitespace.
     let totalsInfo = outputPipe.fileHandleForReading.readDataToEndOfFile()
     // `UInt8(32)` is space in ASCII.
-    let totalsCount = String(data: totalsInfo.prefix(while: { $0 != 32 }), encoding: .utf8)!
+    let totalsCount = String(decoding: totalsInfo.prefix(while: { $0 != 32 }), as: UTF8.self)
     return Int(totalsCount)!
 }
 

Shared/Samples/Navigate route with rerouting/NavigateRouteWithReroutingView.Model.swift

@@ -122,7 +122,7 @@ extension NavigateRouteWithReroutingView {
 
             // Set up the data source's locations using a local JSON file.
             let jsonData = try Data(contentsOf: .sanDiegoTourPath)
-            guard let jsonString = String(data: jsonData, encoding: .utf8) else { return }
+            let jsonString = String(decoding: jsonData, as: UTF8.self)
             let routePolyline = try Polyline.fromJSON(jsonString)
             simulatedDataSource.setSimulatedLocations(with: routePolyline)
 

Shared/Supporting Files/Extensions/Array+RawRepresentable.swift

@@ -29,9 +29,7 @@ extension Array: RawRepresentable where Element == String {
 
     /// The raw value of the array.
     public var rawValue: String {
-        guard let data = try? JSONEncoder().encode(self),
-              let result = String(data: data, encoding: .utf8)
-        else { return "[]" }
-        return result
+        guard let data = try? JSONEncoder().encode(self) else { return "[]" }
+        return String(decoding: data, as: UTF8.self)
     }
 }