Add a simple structure & working test outline

Author: pimterry

package.json

@@ -1,6 +1,6 @@
 {
   "name": "read-tls-fingerprint",
-  "version": "1.0.0",
+  "version": "0.0.0",
   "author": "Tim Perry <[email protected]>",
   "description": "A pure-JS module to read TLS fingerprints from an incoming socket connection",
   "main": "./dist/index.js",
@@ -36,7 +36,8 @@
     "url": "http://github.com/httptoolkit/read-tls-fingerprint.git"
   },
   "dependencies": {
-    "@types/node": "^16.7.10"
+    "@types/node": "^16.7.10",
+    "destroyable-server": "^1.0.0"
   },
   "devDependencies": {
     "@types/chai": "^4.2.21",

src/index.ts

@@ -0,0 +1,6 @@
+import * as stream from "stream";
+
+export async function getTlsFingerprint(data: stream.Readable) {
+    const firstData: any = await new Promise((resolve) => data.on('data', resolve));
+    return firstData[0].toString();
+}

test/test-util.ts

@@ -1,4 +1,3 @@
-import * as stream from 'stream';
 import * as fs from 'fs';
 
 export const testKey = fs.readFileSync(__dirname + '/fixtures/server.key');
@@ -20,14 +19,4 @@ export function getDeferred<T>(): Deferred<T> {
     result.reject = rejectCallback!;
 
     return result;
-}
-
-export async function streamToBuffer(stream: stream.Readable): Promise<Buffer> {
-    const data: Buffer[] = [];
-    stream.on('data', (d) => data.push(d));
-
-    return new Promise((resolve, reject) => {
-        stream.on('end', () => resolve(Buffer.concat(data)));
-        stream.on('error', reject);
-    });
 }

test/test.spec.ts

@@ -1,5 +1,37 @@
+import * as net from 'net';
+import * as tls from 'tls';
+import { makeDestroyable, DestroyableServer } from 'destroyable-server';
+
+import { getDeferred } from './test-util';
+
+import { getTlsFingerprint } from '../src/index';
+import { expect } from 'chai';
+
 describe("Read-TLS-Fingerprint", () => {
-    it("runs a test", () => {
-        // no-op
+
+    let server: DestroyableServer<net.Server>;
+
+    afterEach(() => server?.destroy());
+
+    it("can read Node's fingerprint", async () => {
+        server = makeDestroyable(new net.Server());
+
+        server.listen();
+        await new Promise((resolve) => server.on('listening', resolve));
+
+        let incomingSocketPromise = getDeferred<net.Socket>();
+        server.on('connection', (socket) => incomingSocketPromise.resolve(socket));
+
+        console.log(server.address());
+        const port = (server.address() as net.AddressInfo).port;
+        tls.connect({
+            host: '127.0.0.1',
+            port
+        }).on('error', () => {}); // Socket will fail, since server never responds, that's OK
+
+        const incomingSocket = await incomingSocketPromise;
+        const fingerprint = await getTlsFingerprint(incomingSocket);
+
+        expect(fingerprint).to.equal('22'); // Basic WIP test: yes, this is TLS
     });
 });