Did it

.github/workflows/test.yaml

@@ -19,4 +19,4 @@ jobs:
         run: npm ci
 
       - name: Test
-        run: npm run test
+        run: npm run test

src/secret.ts

@@ -13,7 +13,7 @@
 // 7, 4 -> 3
 // All inputs must be >= 1
 export function secret_1(_num1: number, _num2: number): number {
-    return 0;
+  return _num1 % _num2;
 }
 
 // Implements the following input to output mapping:
@@ -23,7 +23,7 @@ export function secret_1(_num1: number, _num2: number): number {
 // 7, 4 -> 2401
 // All inputs must be >= 1
 export function secret_2(_num1: number, _num2: number): number {
-    return 0;
+  return _num1 ** _num2;
 }
 
 // Implements the following input to output mapping:
@@ -33,7 +33,7 @@ export function secret_2(_num1: number, _num2: number): number {
 // 256 -> 16
 // All inputs must be >= 0
 export function secret_3(_num1: number): number {
-    return 0;
+  return Math.sqrt(_num1);
 }
 
 // Implements the following input to output mapping:
@@ -43,7 +43,15 @@ export function secret_3(_num1: number): number {
 // 7 -> 5040
 // All inputs must be >= 0
 export function secret_4(_num1: number): number {
-    return 0;
+  if (_num1 < 0) {
+    throw new Error("Factorial is not defined for negative numbers");
+  }
+
+  let result = 1;
+  for (let i = 2; i <= _num1; i++) {
+    result *= i;
+  }
+  return result;
 }
 
 // Implements the following input to output mapping:
@@ -53,5 +61,10 @@ export function secret_4(_num1: number): number {
 // 7 -> 13
 // All inputs must be >= 1
 export function secret_5(_num1: number): number {
-    return 0;
+  let a = 0,
+    b = 1;
+  for (let i = 0; i < _num1; i++) {
+    [a, b] = [b, a + b];
+  }
+  return a;
 }