Implement big endian encoding and decoding - Closes #24

src/app/modules/dex/utils/bigEndian.ts

@@ -0,0 +1,26 @@
+// Big Endian Encoding and Decoding
+export const int32be = (x: number) => {
+    const buf = Buffer.allocUnsafe(4);
+    buf.writeInt32BE(x, 0);
+
+    return buf.toString('hex');
+}
+
+export const int32beInv = (bufferX: string) => {
+    const buf = Buffer.from(bufferX, "hex");
+
+    return buf.readInt32BE(0);
+}
+
+export const uint32be = (x: number) => {
+    const buf = Buffer.allocUnsafe(4);
+    buf.writeUInt32BE(x, 0);
+
+    return buf.toString('hex');
+}
+
+export const uint32beInv = (bufferX: string): number => {
+    const buf = Buffer.from(bufferX, "hex");
+
+    return buf.readUInt32BE(0);
+}

test/unit/modules/dex/bigEndian.spec.ts

@@ -0,0 +1,27 @@
+import {
+	int32be,
+	uint32be,
+	int32beInv,
+	uint32beInv
+} from '../../../../src/app/modules/dex/utils/bigEndian';
+
+describe('dex:bigEndian', () => {
+	describe('constructor', () => {
+		it('int32be/int32beInv should convert and revert to original values', async () => {
+			expect(int32be(2147483647)).toEqual('7fffffff');
+			expect(int32beInv('7fffffff')).toEqual(2147483647);
+		});
+		it('uint32be/uint32beInv should convert and revert to original values', async () => {
+			expect(uint32be(4294967295)).toBe('ffffffff');
+			expect(uint32beInv('ffffffff')).toBe(4294967295);
+		});
+		it('int32be/int32beInv should fail on out of bounds values', async () => {
+			expect(() => int32beInv('wrong value')).toThrow();
+			expect(() => int32be(2147483648)).toThrow();
+		});
+		it('uint32be/uint32beInv should fail on out of bounds values', async () => {
+			expect(() => uint32beInv('wrong value')).toThrow();
+			expect(() => uint32be(4294967296)).toThrow();
+		});
+	});
+});

test/unit/modules/dex/utils.sqrt.spec.ts

@@ -1,6 +1,6 @@
 import {
     sqrt
-} from '../../../../src/app/modules/dex/utils/math_constants'
+} from '../../../../src/app/modules/dex/utils/mathConstants'
 import {
     MAX_SQRT_RATIO
 } from '../../../../src/app/modules/dex/constants'
@@ -9,6 +9,5 @@ describe('sqrt', () => {
     it('should calculate sqrt', async () => {
         expect(sqrt(BigInt(100))).toBe(BigInt(10));
         expect(sqrt(MAX_SQRT_RATIO)).toBe(BigInt('1208903099313551102292995'));
-
     });
 });