Add Typescript definitions and adapt callback interface fixed to match de facto usage (#38)

index.js

@@ -38,7 +38,7 @@ var Keychain = {
    */
   getInternetCredentials: function(
     server: string,
-    callback?: ?(error: ?Error, result: ?string) => void
+    callback?: ?(error: ?Error, username: ?string, password: ?string) => void
   ): Promise {
     return new Promise((resolve, reject) => {
       RNKeychainManager.getInternetCredentialsForServer(server, function(err, username, password) {
@@ -110,7 +110,7 @@ var Keychain = {
    */
   getGenericPassword: function(
     service?: string,
-    callback?: ?(error: ?Error, result: ?string) => void
+    callback?: ?(error: ?Error, username: ?string, password: ?string) => void
   ): Promise {
     return new Promise((resolve, reject) => {
       RNKeychainManager.getGenericPasswordForService(service, function(err, username, password) {

package.json

@@ -24,6 +24,9 @@
   "bugs": {
     "url": "https://github.com/oblador/react-native-keychain/issues"
   },
+  "typescript": {
+    "definition": "typings/react-native-keychain.d.ts"
+  },
   "repository": {
     "type": "git",
     "url": "git://github.com/oblador/react-native-keychain.git"

typings/react-native-keychain.d.ts

@@ -0,0 +1,43 @@
+declare module 'react-native-keychain' {
+
+    export interface UserCredentials {
+        username: string;
+        password: string;
+    }
+
+    function setInternetCredentials(
+        server: string,
+        username: string,
+        password: string,
+        callback?: (error?: Error) => void
+    ): Promise<void>;
+
+    function getInternetCredentials(
+        server: string,
+        callback?: (error?: Error, username?: string, password?: string) => void
+    ): Promise<UserCredentials>;
+
+    function resetInternetCredentials(
+        server: string,
+        callback?: (error?: Error) => void
+    ): Promise<void>;
+
+    function setGenericPassword(
+        username: string,
+        password: string,
+        service?: string,
+        callback?: (error?: Error) => void
+    ): Promise<void>;
+
+
+  function getGenericPassword(
+    service?: string,
+    callback?: (error?: Error, result?: string) => void
+  ): Promise<void>;
+
+  function resetGenericPassword (
+    service?: string,
+    callback?: (error?: Error) => void
+  ): Promise<void>;
+
+}