diff --git a/test/VexCRC.spec.ts b/test/VexCRC.spec.ts
new file mode 100644
index 0000000..600046a
--- /dev/null
+++ b/test/VexCRC.spec.ts
@@ -0,0 +1,26 @@
+import crc16ccitt from 'crc/calculators/crc16ccitt';
+import { CrcGenerator } from '../src';
+
+
+function getRandomInt(max: number) {
+    return Math.floor(Math.random() * max);
+}
+
+function getRandomUInt8Array(size: number) {
+    let rtn: number[] = [];
+    for (let i = 0; i < size; i++) {
+        rtn.push(getRandomInt(256));
+    }
+    return new Uint8Array(rtn);
+}
+
+const crcgen = new CrcGenerator();
+
+test("CRC 16 ccitt", async () => {
+    for (let i = 10; i < 100; i++) {
+        let test = getRandomUInt8Array(i);
+        if (crc16ccitt(test, 0) !== crcgen.crc16(test, 0)) {
+            fail();
+        }
+    }
+});
\ No newline at end of file
diff --git a/test/VexEvent.spec.ts b/test/VexEvent.spec.ts
new file mode 100644
index 0000000..3d9ae48
--- /dev/null
+++ b/test/VexEvent.spec.ts
@@ -0,0 +1,44 @@
+import { VexEventTarget } from "../src";
+
+function getRandomInt(max: number) {
+    return Math.floor(Math.random() * max);
+}
+
+test("VexEventEmitter and VexEventTarget", async () => {
+    let target = new VexEventTarget();
+
+    let fn1 = jest.fn();
+    let fn2 = jest.fn();
+
+    target.remove("test1", fn1);
+
+    target.emit("test1", undefined);
+
+
+    target.on("test", fn1);
+
+    let r1 = getRandomInt(10) + 10;
+    for (let i = 0; i < r1; i++) target.emit("test", undefined);
+
+    target.on("test", fn2);
+
+    let r2 = getRandomInt(10) + 10;
+    for (let i = 0; i < r2; i++) target.emit("test", undefined);
+
+    expect(fn1).toBeCalledTimes(r1 + r2);
+    expect(fn2).toBeCalledTimes(r2);
+
+    target.remove("test", fn1);
+
+    target.emit("test", undefined);
+
+    expect(fn1).toBeCalledTimes(r1 + r2);
+    expect(fn2).toBeCalledTimes(r2 + 1);
+
+    target.clearListeners();
+
+    target.emit("test", undefined);
+
+    expect(fn1).toBeCalledTimes(r1 + r2);
+    expect(fn2).toBeCalledTimes(r2 + 1);    
+});
\ No newline at end of file
diff --git a/test/VexFirmwareVersion.spec.ts b/test/VexFirmwareVersion.spec.ts
new file mode 100644
index 0000000..49ab1de
--- /dev/null
+++ b/test/VexFirmwareVersion.spec.ts
@@ -0,0 +1,40 @@
+import { VexFirmwareVersion } from "../src";
+
+function getRandomInt(max: number) {
+    return Math.floor(Math.random() * max);
+}
+
+test("Constructor, fromString, fromCatalogString and Uint8 related methods", async () => {
+    for (let i = 0; i < 1000; i++) {
+        let a = getRandomInt(256), b = getRandomInt(256), c = getRandomInt(256), d = getRandomInt(256);
+
+        let subject = new VexFirmwareVersion(a, b, c, d);
+        let str = `${a}.${b}.${c}.b${d}`;
+
+        expect(subject.toInternalString()).toBe(str);
+        expect(VexFirmwareVersion.fromString(str)).toEqual(subject);
+        expect(VexFirmwareVersion.fromCatalogString(`${a}_${b}_${c}_b${d}`)).toEqual(subject);
+        expect(VexFirmwareVersion.fromUint8Array(subject.toUint8Array(false)).toInternalString()).toBe(str);
+        expect(VexFirmwareVersion.fromUint8Array(subject.toUint8Array(true), 0, true).toInternalString()).toBe(str);
+        subject.beta = 0;
+        expect(VexFirmwareVersion.fromString(`${a}.${b}.${c}`)).toEqual(subject);
+    }
+});
+
+test("Compare", async () => {
+    let base = new VexFirmwareVersion(1, 2, 3, 4);
+    expect(base.compare(base)).toBe(0);
+    expect(new VexFirmwareVersion(1, 2, 3, 5).compare(base)).toBe(1);
+    expect(new VexFirmwareVersion(1, 2, 4, 5).compare(base)).toBe(1);
+    expect(new VexFirmwareVersion(1, 3, 4, 5).compare(base)).toBe(1);
+    expect(new VexFirmwareVersion(2, 3, 4, 5).compare(base)).toBe(1);
+});
+
+test("Is beta", async () => {
+    expect(VexFirmwareVersion.allZero().isBeta()).toBeFalsy();
+    expect(new VexFirmwareVersion(0, 0, 0, 1).isBeta()).toBeTruthy();
+});
+
+test("All zero", async () => {
+    expect(VexFirmwareVersion.allZero().toInternalString()).toBe("0.0.0.b0");
+});