chapter 05: making authentication depending of a concrete class of us…

…erProvider, dependency inversion still is been violated

chapter-05-the-dependency-inversion-principle/refactor/authentication.js

@@ -0,0 +1,17 @@
+function authentication(userProvider) {
+    function checkCredentials(username, password) {
+        const user = userProvider.findUser(username);
+
+        if (user === null) {
+            new Error('User not found');
+        }
+
+        //validate password...
+    }
+
+    return {
+        checkCredentials,
+    };
+}
+
+module.exports = authentication;

chapter-05-the-dependency-inversion-principle/refactor/userProvider.js

@@ -0,0 +1,13 @@
+function userProvider(connection) {
+    function findUser(username) {
+        return connection.fetchAssoc('SELECT * FROM users WHERE username = ?', [
+            username,
+        ]);
+    }
+
+    return {
+        findUser,
+    };
+}
+
+module.exports = userProvider;