test: number utils

test/node/utils/number_utils.test.ts

@@ -0,0 +1,130 @@
+import { expect } from 'chai';
+import { NumberUtils } from '../../../src/utils/number_utils';
+
+describe.only('NumberUtils', () => {
+  /** Make a Uint8Array in a less verbose way */
+  const b = (...values) => new Uint8Array(values);
+
+  context('getInt32LE()', () => {
+    it('parses an int32 little endian', () => {
+      expect(NumberUtils.getInt32LE(b(0, 0, 0, 1), 0)).to.equal(1 << 24);
+    });
+
+    it('parses an signed int32 little endian', () => {
+      expect(NumberUtils.getInt32LE(b(255, 255, 255, 255), 0)).to.equal(-1);
+    });
+
+    it('parses an int32 little endian at offset', () => {
+      expect(NumberUtils.getInt32LE(b(0, 0, 0, 0, 0, 1), 2)).to.equal(1 << 24);
+    });
+
+    it('does not check bounds of offset', () => {
+      expect(NumberUtils.getInt32LE(b(0, 0, 0, 1), 4)).to.equal(0);
+    });
+  });
+
+  context('getUint32LE()', () => {
+    it('parses an unsigned int32 little endian', () => {
+      expect(NumberUtils.getUint32LE(b(255, 255, 255, 255), 0)).to.equal(0xffff_ffff);
+    });
+
+    it('parses an int32 little endian at offset', () => {
+      expect(NumberUtils.getUint32LE(b(0, 0, 255, 255, 255, 255), 2)).to.equal(0xffff_ffff);
+    });
+
+    it('does not check bounds of offset', () => {
+      expect(NumberUtils.getUint32LE(b(0, 0, 0, 1), 4)).to.be.NaN;
+    });
+  });
+
+  context('getUint32BE()', () => {
+    it('parses an int32 big endian', () => {
+      expect(NumberUtils.getUint32BE(b(0, 0, 0, 1), 0)).to.equal(1);
+    });
+
+    it('parses an unsigned int32 big endian', () => {
+      expect(NumberUtils.getUint32LE(b(255, 255, 255, 255), 0)).to.equal(0xffff_ffff);
+    });
+
+    it('parses an int32 big endian at offset', () => {
+      expect(NumberUtils.getUint32BE(b(0, 0, 0, 0, 0, 1), 2)).to.equal(1);
+    });
+
+    it('does not check bounds of offset', () => {
+      expect(NumberUtils.getUint32BE(b(0, 0, 0, 1), 4)).to.be.NaN;
+    });
+  });
+
+  context('getBigInt64LE()', () => {
+    it('parses an int64 little endian', () => {
+      expect(NumberUtils.getBigInt64LE(b(0, 0, 0, 0, 0, 0, 0, 1), 0)).to.equal(1n << 56n);
+    });
+
+    it('parses an int64 little endian at offset', () => {
+      expect(NumberUtils.getBigInt64LE(b(0, 0, 0, 0, 0, 0, 0, 0, 0, 1), 2)).to.equal(1n << 56n);
+    });
+
+    it('throws if offset is out of bounds', () => {
+      expect(() => NumberUtils.getBigInt64LE(b(0, 0, 0, 0, 0, 0, 0, 1), 4)).to.throw(RangeError);
+    });
+  });
+
+  context('getFloat64LE()', () => {
+    /** 2.3 in bytes */
+    const num = [0x66, 0x66, 0x66, 0x66, 0x66, 0x66, 0x02, 0x40];
+
+    it('parses an float64 little endian', () => {
+      expect(NumberUtils.getFloat64LE(b(...num), 0)).to.equal(2.3);
+    });
+
+    it('parses an float64 little endian at offset', () => {
+      expect(NumberUtils.getFloat64LE(b(0, 0, ...num), 2)).to.equal(2.3);
+    });
+
+    it('does not check bounds of offset', () => {
+      expect(NumberUtils.getFloat64LE(b(...num), 4)).to.not.equal(2.3);
+    });
+  });
+
+  context('setInt32BE()', () => {
+    it('writes an int32 big endian', () => {
+      const space = new Uint8Array(4);
+      expect(NumberUtils.setInt32BE(space, 0, 1)).to.equal(4);
+      expect(space).to.deep.equal(b(0, 0, 0, 1));
+    });
+
+    it('writes an int32 big endian at offset', () => {
+      const space = new Uint8Array(6);
+      expect(NumberUtils.setInt32BE(space, 2, 1)).to.equal(4);
+      expect(space).to.deep.equal(b(0, 0, 0, 0, 0, 1));
+    });
+
+    it('does not bound or type check', () => {
+      const space = {};
+      // @ts-expect-error: testing incorrect type
+      expect(NumberUtils.setInt32BE(space, 'a', 1)).to.equal(4);
+      expect(space).to.deep.equal({ a: 0, a1: 0, a2: 0, a3: 1 });
+    });
+  });
+
+  context('setInt32LE()', () => {
+    it('writes an int32 big endian', () => {
+      const space = new Uint8Array(4);
+      expect(NumberUtils.setInt32LE(space, 0, 1)).to.equal(4);
+      expect(space).to.deep.equal(b(1, 0, 0, 0));
+    });
+
+    it('writes an int32 big endian at offset', () => {
+      const space = new Uint8Array(6);
+      expect(NumberUtils.setInt32LE(space, 2, 1)).to.equal(4);
+      expect(space).to.deep.equal(b(0, 0, 1, 0, 0, 0));
+    });
+
+    it('does not bound or type check', () => {
+      const space = {};
+      // @ts-expect-error: testing incorrect type
+      expect(NumberUtils.setInt32LE(space, 'a', 1)).to.equal(4);
+      expect(space).to.deep.equal({ a: 1, a1: 0, a2: 0, a3: 0 });
+    });
+  });
+});