feat: Add support for browser contract tests. (#582)

This adds the contract tests, but does not yet automate running them.

package.json

@@ -23,7 +23,9 @@
     "packages/store/node-server-sdk-dynamodb",
     "packages/telemetry/node-server-sdk-otel",
     "packages/tooling/jest",
-    "packages/sdk/browser"
+    "packages/sdk/browser",
+    "packages/sdk/browser/contract-tests/entity",
+    "packages/sdk/browser/contract-tests/adapter"
   ],
   "private": true,
   "scripts": {

packages/sdk/browser/contract-tests/adapter/package.json

@@ -0,0 +1,40 @@
+{
+  "name": "browser-contract-test-adapter",
+  "version": "1.0.0",
+  "description": "Adapts REST interface to a websocket for use in browsers.",
+  "main": "dist/index.js",
+  "scripts": {
+    "build": "tsc",
+    "start": "yarn build && node dist/index.js",
+    "lint": "eslint ./src",
+    "prettier": "prettier --write '**/*.@(js|ts|tsx|json|css)' --ignore-path ../../../../.prettierignore"
+  },
+  "author": "",
+  "license": "UNLICENSED",
+  "dependencies": {
+    "body-parser": "^1.20.3",
+    "cors": "^2.8.5",
+    "express": "^4.21.0",
+    "ws": "^8.18.0"
+  },
+  "devDependencies": {
+    "@eslint/js": "^9.10.0",
+    "@trivago/prettier-plugin-sort-imports": "^4.1.1",
+    "@types/cors": "^2.8.17",
+    "@types/express": "^4.17.21",
+    "@types/ws": "^8.5.12",
+    "@typescript-eslint/eslint-plugin": "^6.20.0",
+    "@typescript-eslint/parser": "^6.20.0",
+    "eslint": "^8.45.0",
+    "eslint-config-airbnb-base": "^15.0.0",
+    "eslint-config-airbnb-typescript": "^17.1.0",
+    "eslint-config-prettier": "^8.8.0",
+    "eslint-plugin-import": "^2.27.5",
+    "eslint-plugin-jest": "^27.6.3",
+    "eslint-plugin-prettier": "^5.0.0",
+    "globals": "^15.9.0",
+    "prettier": "^3.0.0",
+    "typescript": "^5.6.2",
+    "typescript-eslint": "^8.5.0"
+  }
+}

packages/sdk/browser/contract-tests/adapter/src/index.ts

@@ -0,0 +1,112 @@
+/* eslint-disable no-console */
+
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import bodyParser from 'body-parser';
+import cors from 'cors';
+import { randomUUID } from 'crypto';
+import express from 'express';
+import http from 'node:http';
+import util from 'node:util';
+import { WebSocketServer } from 'ws';
+
+let server: http.Server | undefined;
+
+async function main() {
+  const wss = new WebSocketServer({ port: 8001 });
+  const waiters: Record<string, (data: unknown) => void> = {};
+
+  console.log('Running contract test harness adapter.');
+  wss.on('connection', async (ws) => {
+    ws.on('error', console.error);
+
+    ws.on('message', (stringData: string) => {
+      const data = JSON.parse(stringData);
+      if (Object.prototype.hasOwnProperty.call(waiters, data.reqId)) {
+        waiters[data.reqId](data);
+        delete waiters[data.reqId];
+      } else {
+        console.error('Did not find outstanding request', data.reqId);
+      }
+    });
+
+    const send = (data: { [key: string]: unknown; reqId: string }): Promise<any> => {
+      let resolver: (data: unknown) => void;
+      const waiter = new Promise((resolve) => {
+        resolver = resolve;
+      });
+      // @ts-expect-error The body of the above assignment runs sequentially.
+      waiters[data.reqId] = resolver;
+      ws.send(JSON.stringify(data));
+      return waiter;
+    };
+
+    if (server) {
+      await util.promisify(server.close).call(server);
+      server = undefined;
+    }
+
+    const app = express();
+
+    const port = 8000;
+
+    app.use(
+      cors({
+        origin: '*',
+        allowedHeaders: '*',
+        methods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'],
+      }),
+    );
+    app.use(bodyParser.json());
+
+    app.get('/', async (_req, res) => {
+      const commandResult = await send({ command: 'getCapabilities', reqId: randomUUID() });
+      res.header('Content-Type', 'application/json');
+      res.json(commandResult);
+    });
+
+    app.delete('/', () => {
+      process.exit();
+    });
+
+    app.post('/', async (req, res) => {
+      const commandResult = await send({
+        command: 'createClient',
+        body: req.body,
+        reqId: randomUUID(),
+      });
+      if (commandResult.resourceUrl) {
+        res.set('Location', commandResult.resourceUrl);
+      }
+      if (commandResult.status) {
+        res.status(commandResult.status);
+      }
+      res.send();
+    });
+
+    app.post('/clients/:id', async (req, res) => {
+      const commandResult = await send({
+        command: 'runCommand',
+        id: req.params.id,
+        body: req.body,
+        reqId: randomUUID(),
+      });
+      if (commandResult.status) {
+        res.status(commandResult.status);
+      }
+      if (commandResult.body) {
+        res.write(JSON.stringify(commandResult.body));
+      }
+      res.send();
+    });
+
+    app.delete('/clients/:id', async (req, res) => {
+      await send({ command: 'deleteClient', id: req.params.id, reqId: randomUUID() });
+      res.send();
+    });
+
+    server = app.listen(port, () => {
+      console.log('Listening on port %d', port);
+    });
+  });
+}
+main();

packages/sdk/browser/contract-tests/adapter/tsconfig.eslint.json

@@ -0,0 +1,5 @@
+{
+  "extends": "./tsconfig.json",
+  "include": ["/**/*.ts"],
+  "exclude": ["node_modules"]
+}

packages/sdk/browser/contract-tests/adapter/tsconfig.json

@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "target": "ES6",
+    "module": "commonjs",
+    "esModuleInterop": true,
+    "forceConsistentCasingInFileNames": true,
+    "strict": true,
+    "moduleResolution": "node",
+    "outDir": "dist",
+    "sourceMap": true
+  },
+  "lib": ["ES6"],
+  "exclude": ["**/*.test.ts", "dist", "node_modules"]
+}

packages/sdk/browser/contract-tests/adapter/tsconfig.ref.json

@@ -0,0 +1,7 @@
+{
+  "extends": "./tsconfig.json",
+  "include": ["src/**/*", "package.json"],
+  "compilerOptions": {
+    "composite": true
+  }
+}

packages/sdk/browser/contract-tests/entity/index.html

@@ -0,0 +1,13 @@
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/vite.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>SDK Contract Test Service</title>
+  </head>
+  <body>
+    <div id="app"></div>
+    <script type="module" src="/src/main.ts"></script>
+  </body>
+</html>

packages/sdk/browser/contract-tests/entity/package.json

@@ -0,0 +1,30 @@
+{
+  "name": "browser-contract-test-service",
+  "private": true,
+  "version": "0.0.0",
+  "type": "module",
+  "description": "Contract test service implementation for @launchdarkly/js-client-sdk",
+  "scripts": {
+    "start": "vite --open=true",
+    "lint": "eslint ./src",
+    "prettier": "prettier --write '**/*.@(js|ts|tsx|json|css)' --ignore-path ../../../../.prettierignore"
+  },
+  "dependencies": {
+    "@launchdarkly/js-client-sdk": "0.0.0"
+  },
+  "devDependencies": {
+    "@trivago/prettier-plugin-sort-imports": "^4.1.1",
+    "@typescript-eslint/eslint-plugin": "^6.20.0",
+    "@typescript-eslint/parser": "^6.20.0",
+    "eslint": "^8.45.0",
+    "eslint-config-airbnb-base": "^15.0.0",
+    "eslint-config-airbnb-typescript": "^17.1.0",
+    "eslint-config-prettier": "^8.8.0",
+    "eslint-plugin-import": "^2.27.5",
+    "eslint-plugin-jest": "^27.6.3",
+    "eslint-plugin-prettier": "^5.0.0",
+    "prettier": "^3.0.0",
+    "typescript": "^5.5.3",
+    "vite": "^5.4.1"
+  }
+}