From aa1cae428b8329197db94ae52662e78ba4d87b64 Mon Sep 17 00:00:00 2001
From: Joel Wetzell <jwetzell@yahoo.com>
Date: Mon, 21 Oct 2024 12:44:43 -0500
Subject: [PATCH] add function to guess type and decode

---
 packages/osc/src/index.ts         | 14 +++++++++++
 packages/osc/tests/decode.test.js | 41 +++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+)
 create mode 100644 packages/osc/tests/decode.test.js

diff --git a/packages/osc/src/index.ts b/packages/osc/src/index.ts
index 8d70e01..1ed8b3a 100644
--- a/packages/osc/src/index.ts
+++ b/packages/osc/src/index.ts
@@ -1,3 +1,17 @@
+import { bundleFromBuffer } from './bundle';
+import { messageFromBuffer } from './message';
+import { OSCBundle, OSCMessage } from './models';
+
 export * from './models';
 export * from './message';
 export * from './bundle';
+
+export function fromBuffer(bytes: Uint8Array): [OSCBundle | OSCMessage | undefined, Uint8Array | undefined] {
+    if (bytes[0] === 47) { // starts with '/'
+        return messageFromBuffer(bytes);
+    } else if (bytes[0] === 35) { // starts with '#'
+        return bundleFromBuffer(bytes)
+    } else {
+        throw new Error('bytes do not look like an OSC message or bundle');
+    }
+}
\ No newline at end of file
diff --git a/packages/osc/tests/decode.test.js b/packages/osc/tests/decode.test.js
new file mode 100644
index 0000000..d18a172
--- /dev/null
+++ b/packages/osc/tests/decode.test.js
@@ -0,0 +1,41 @@
+const { deepEqual, equal, throws } = require('assert');
+const { describe, it } = require('node:test');
+const osc = require('../dist/index');
+
+const tests = [
+    {
+        description: 'simple bundle',
+        expected: {
+          timeTag: [32, 0],
+          contents: [{ address: '/oscillator/4/frequency', args: [{ type: 'f', value: 440 }] }],
+        },
+        bytes: new Uint8Array([
+          ...new TextEncoder().encode('#bundle'),
+          ...new Uint8Array([0x00]),
+          ...new Uint8Array([0, 0, 0, 32, 0, 0, 0, 0]),
+          ...new Uint8Array([0x00, 0x00, 0x00, 0x20]),
+          ...new Uint8Array([
+            0x2f, 0x6f, 0x73, 0x63, 0x69, 0x6c, 0x6c, 0x61, 0x74, 0x6f, 0x72, 0x2f, 0x34, 0x2f, 0x66, 0x72, 0x65, 0x71,
+            0x75, 0x65, 0x6e, 0x63, 0x79, 0x00, 0x2c, 0x66, 0x00, 0x00, 0x43, 0xdc, 0x00, 0x00,
+          ]),
+        ]),
+      },
+      {
+        description: 'osc 1.0 spec example 1',
+        bytes: new Uint8Array([
+          47, 111, 115, 99, 105, 108, 108, 97, 116, 111, 114, 47, 52, 47, 102, 114, 101, 113, 117, 101, 110, 99, 121, 0, 44,
+          102, 0, 0, 67, 220, 0, 0,
+        ]),
+        expected: { address: '/oscillator/4/frequency', args: [{ type: 'f', value: 440 }] },
+      },
+]
+
+describe('OSC Bytes Decoding', () => {
+    tests.forEach((bytesTest) => {
+      it(bytesTest.description, () => {
+        const [decoded, remainingBytes] = osc.fromBuffer(bytesTest.bytes);
+        deepEqual(decoded, bytesTest.expected);
+        equal(remainingBytes.length, 0)
+      });
+    });
+  });
\ No newline at end of file