Fix warning(s): 'characters' is deprecated: Please use String or Substring directly (p2#251)

Author: everlof

Sources/Base/OAuth2Requestable.swift

@@ -197,10 +197,10 @@ open class OAuth2Requestable {
 	- returns: A dictionary full of strings with the key-value pairs found in the query
 	*/
 	public final class func params(fromQuery query: String) -> OAuth2StringDict {
-		let parts = query.characters.split() { $0 == "&" }.map() { String($0) }
+		let parts = query.split() { $0 == "&" }.map() { String($0) }
 		var params = OAuth2StringDict(minimumCapacity: parts.count)
 		for part in parts {
-			let subparts = part.characters.split() { $0 == "=" }.map() { String($0) }
+			let subparts = part.split() { $0 == "=" }.map() { String($0) }
 			if 2 == subparts.count {
 				params[subparts[0]] = subparts[1].wwwFormURLDecodedString
 			}

Sources/Flows/OAuth2CodeGrant.swift

@@ -133,7 +133,7 @@ open class OAuth2CodeGrant: OAuth2 {
 		if !(redirect.absoluteString.hasPrefix(expectRedirect)) && (!(redirect.absoluteString.hasPrefix("urn:ietf:wg:oauth:2.0:oob")) && "localhost" != comp?.host) {
 			throw OAuth2Error.invalidRedirectURL("Expecting «\(expectRedirect)» but received «\(redirect)»")
 		}
-		if let compQuery = comp?.query, compQuery.characters.count > 0 {
+		if let compQuery = comp?.query, compQuery.count > 0 {
 			let query = OAuth2CodeGrant.params(fromQuery: comp!.percentEncodedQuery!)
 			try assureNoErrorInResponse(query as OAuth2JSON)
 			if let cd = query["code"] {

Sources/Flows/OAuth2ImplicitGrant.swift

@@ -42,7 +42,7 @@ open class OAuth2ImplicitGrant: OAuth2 {
 		do {
 			// token should be in the URL fragment
 			let comp = URLComponents(url: redirect, resolvingAgainstBaseURL: true)
-			guard let fragment = comp?.percentEncodedFragment, fragment.characters.count > 0 else {
+			guard let fragment = comp?.percentEncodedFragment, fragment.count > 0 else {
 				throw OAuth2Error.invalidRedirectURL(redirect.description)
 			}