[REFACTOR] ESLint manual fixes: TS2533: Object is possibly 'null' or 'undefined'"

https://timmousk.com/blog/typescript-object-is-possibly-null/

Author: Gonzalo Diaz

src/hackerrank/interview_preparation_kit/arrays/new_year_chaos.test.ts

@@ -27,7 +27,7 @@ describe('new_year_chaos', () => {
       const answer = minimumBribesTransform(value.input);
 
       console.debug(
-        `minimumBribesTransform(${value.input}) solution found: ${answer}`
+        `minimumBribesTransform(${value.input.toString()}) solution found: ${answer}`
       );
 
       expect(answer).toStrictEqual(value.expected);

src/projecteuler/helpers/matrix.ts

@@ -4,10 +4,10 @@ export const matrix = (
   m: number,
   n: number,
   init: nullable<number>
-): number[][] => {
+): nullable<number>[][] => {
   const result = [];
   for (let i = 0; i < n; i++) {
-    result.push(new Array(m).fill(init));
+    result.push(new Array<nullable<number>>(m).fill(init));
   }
 
   return result;

src/projecteuler/problem0015.ts

@@ -3,15 +3,15 @@
  */
 
 import { logger as console } from '../logger';
-import { matrix } from './helpers';
+import { matrix, nullable } from './helpers';
 
-function problem0015(gridSide = 20): number {
+function problem0015(gridSide = 20): nullable<number> {
   const vertexMatrix = matrix(gridSide + 1, gridSide + 1, 1);
 
   for (let i = 1; i <= gridSide; i++) {
     for (let j = 1; j <= gridSide; j++) {
-      const upperParent = vertexMatrix[i - 1][j];
-      const leftParent = vertexMatrix[i][j - 1];
+      const upperParent: number = vertexMatrix[i - 1][j]!;
+      const leftParent: number = vertexMatrix[i][j - 1]!;
 
       vertexMatrix[i][j] = upperParent + leftParent;
     }