make kestrel a tak server, so that it can send and receive pois as cots data

test/unit/cotRouter.spec.js

@@ -0,0 +1,27 @@
+import { describe, it, expect } from 'vitest'
+import { isCotFirstByte, COT_FIRST_BYTE_TAK, COT_FIRST_BYTE_XML } from '../../server/utils/cotRouter.js'
+
+describe('cotRouter', () => {
+  describe('isCotFirstByte', () => {
+    it('returns true for TAK Protocol (0xBF)', () => {
+      expect(isCotFirstByte(0xBF)).toBe(true)
+      expect(isCotFirstByte(COT_FIRST_BYTE_TAK)).toBe(true)
+    })
+
+    it('returns true for traditional XML (<)', () => {
+      expect(isCotFirstByte(0x3C)).toBe(true)
+      expect(isCotFirstByte(COT_FIRST_BYTE_XML)).toBe(true)
+    })
+
+    it('returns false for HTTP-like first bytes', () => {
+      expect(isCotFirstByte(0x47)).toBe(false) // 'G' GET
+      expect(isCotFirstByte(0x50)).toBe(false) // 'P' POST
+      expect(isCotFirstByte(0x48)).toBe(false) // 'H' HEAD
+    })
+
+    it('returns false for other bytes', () => {
+      expect(isCotFirstByte(0x00)).toBe(false)
+      expect(isCotFirstByte(0x16)).toBe(false) // TLS client hello
+    })
+  })
+})