fix: integer length

src/lib/typescript/functions/index.ts

@@ -1,4 +1,4 @@
-export * from './num-length.function';
+export * from './integer-length.function';
 export * from './num-start.function';
 export * from './num-at.function';
 export * from './lcm.function';

src/lib/typescript/functions/integer-length.function.spec.ts

@@ -0,0 +1,43 @@
+import { expect } from 'chai';
+import { integerLength, integerLengthMath } from './integer-length.function';
+
+describe(`Integer length`, () => {
+	it(`should work with numbers larger than 1`, async () => {
+		expect(integerLength(123)).to.equal(3);
+		expect(integerLength(7653)).to.equal(4);
+		expect(integerLength(85476847)).to.equal(8);
+	});
+
+	it(`should work with 1`, async () => {
+		expect(integerLength(1)).to.equal(1);
+	});
+
+	it(`should work with 0`, async () => {
+		expect(integerLength(0)).to.equal(1);
+	});
+
+	it(`should work with negative numbers`, async () => {
+		expect(integerLength(-34312)).to.equal(5);
+	});
+});
+
+// tslint:disable: deprecation
+describe(`Integer length (Math)`, () => {
+	it(`should work with numbers larger than 1`, async () => {
+		expect(integerLengthMath(123)).to.equal(3);
+		expect(integerLengthMath(7653)).to.equal(4);
+		expect(integerLengthMath(85476847)).to.equal(8);
+	});
+
+	it(`should work with 1`, async () => {
+		expect(integerLengthMath(1)).to.equal(1);
+	});
+
+	it(`should work with 0`, async () => {
+		expect(integerLengthMath(0)).to.equal(0);
+	});
+
+	it(`should work with negative numbers`, async () => {
+		expect(integerLengthMath(-34312)).to.equal(5);
+	});
+});

src/lib/typescript/functions/num-length.function.ts → src/lib/typescript/functions/integer-length.function.ts

@@ -2,7 +2,7 @@
  * Returns the length of the integer part of a number.
  */
 export function integerLength(n: number): number {
-	return Math.floor(n).toString().length;
+	return Math.floor(Math.abs(n)).toString().length;
 }
 
 /**

src/lib/typescript/functions/num-at.function.ts

@@ -6,7 +6,7 @@
  * @param n the number of whichs length will be returned
  */
 export function numAt(n: number, p: number): number {
-	return parseInt(n.toString()[p], 10);
+	return parseInt(n.toString()[p], 10) || 0;
 }
 
 /**

src/lib/typescript/intcode/intcode.class.ts

@@ -1,4 +1,4 @@
-import { numAt, numLength } from '@lib/functions';
+import { integerLength, numAt } from '@lib/functions';
 import { Instruction, toInstruction } from './instruction.enum';
 import { Mode } from './mode.enum';
 
@@ -130,7 +130,7 @@ export class IntCodeComputer implements Iterable<number | undefined> {
 	}
 
 	private getMode(v: number, n: number): Mode | undefined {
-		return numAt(v, numLength(v) - n - 3);
+		return numAt(v, integerLength(v) - n - 3);
 	}
 
 	public *[Symbol.iterator](): IterableIterator<number | undefined> {