feat(openfeature-node-provider): enhance todo feature management with config and validation (#330)

Author: pavkam

packages/openfeature-node-provider/example/app.ts

@@ -1,15 +1,15 @@
 import express from "express";
 import "./bucket";
 import { EvaluationContext, OpenFeature } from "@openfeature/server-sdk";
-import provider from "./bucket";
+import provider, { CreateTodosConfig } from "./bucket";
 
-// In the following, we assume that targetingKey is a unique identifier for the user
+// In the following, we assume that targetingKey is a unique identifier for the user.
 type Context = EvaluationContext & {
   targetingKey: string;
   companyId: string;
 };
 
-// Augment the Express types to include the some context property on the `res.locals` object
+// Augment the Express types to include the some context property on the `res.locals` object.
 declare global {
   namespace Express {
     interface Locals {
@@ -36,6 +36,7 @@ const todos = ["Buy milk", "Walk the dog"];
 app.get("/", (_req, res) => {
   const ofClient = OpenFeature.getClient();
   ofClient.track("front-page-viewed", res.locals.context);
+
   res.json({ message: "Ready to manage some TODOs!" });
 });
 
@@ -46,7 +47,7 @@ app.get("/todos", async (req, res) => {
   // and that the indexing for feature name below is type-checked at compile time.
   const ofClient = OpenFeature.getClient();
   const isEnabled = await ofClient.getBooleanValue(
-    "show-todo",
+    "show-todos",
     false,
     res.locals.context,
   );
@@ -75,10 +76,23 @@ app.post("/todos", async (req, res) => {
     res.locals.context,
   );
 
-  // Check if the user has the "create-todos" feature enabled
+  // Check if the user has the "create-todos" feature enabled.
   if (isEnabled) {
+    // Get the configuration for the "create-todos" feature.
+    // We expect the configuration to be a JSON object with a `maxLength` property.
+    const config = await ofClient.getObjectValue<CreateTodosConfig>(
+      "create-todos",
+      { maxLength: 100 },
+      res.locals.context,
+    );
+
+    // Check if the todo is too long.
+    if (todo.length > config.maxLength) {
+      return res.status(400).json({ error: "Todo is too long" });
+    }
+
     // Track the feature usage
-    ofClient.track("create-todo", res.locals.context);
+    ofClient.track("create-todos", res.locals.context);
     todos.push(todo);
 
     return res.status(201).json({ todo });
@@ -98,15 +112,15 @@ app.delete("/todos/:idx", async (req, res) => {
 
   const ofClient = OpenFeature.getClient();
   const isEnabled = await ofClient.getBooleanValue(
-    "delete-todo",
+    "delete-todos",
     false,
     res.locals.context,
   );
 
   if (isEnabled) {
     todos.splice(idx, 1);
 
-    ofClient.track("delete-todo", res.locals.context);
+    ofClient.track("delete-todos", res.locals.context);
     return res.json({});
   }
 

packages/openfeature-node-provider/example/bucket.ts

@@ -5,11 +5,29 @@ if (!process.env.BUCKET_SECRET_KEY) {
   throw new Error("BUCKET_SECRET_KEY is required");
 }
 
+export type CreateTodosConfig = {
+  maxLength: number;
+};
+
 const provider = new BucketNodeProvider({
   secretKey: process.env.BUCKET_SECRET_KEY!,
-  fallbackFeatures: ["show-todos"],
+  fallbackFeatures: {
+    "show-todos": {
+      isEnabled: true,
+    },
+    "create-todos": {
+      isEnabled: true,
+      config: {
+        key: "default",
+        payload: {
+          maxLength: 100,
+        },
+      },
+    },
+  },
   logger: console,
 });
+
 OpenFeature.setProvider(provider);
 
 export default provider;