Add Increment and Decrement Functions

README.md

@@ -79,7 +79,7 @@ Before submitting a pull request, please make sure the following is done:
 - Fork the repository and create your feature branch from dev.
 - Run `npm install` to have all dependencies.
 - To start development run `npm run test:watch`.
-- Write tests in `src/<scope>/<name>.test.ts` and implementation in `src/<scope>/<name>.ts`.
+- Write tests in `src/<scope>/<name>.spec.ts` and implementation in `src/<scope>/<name>.ts`.
 - Add the documentation page to the `docs/<scope>/<function>.mdx` and update `docs/<scope>/_meta.json` file.
 - Ensure everything is ok `npm run verify`.
 

docs/pages/number/_meta.json

@@ -1,6 +1,8 @@
 {
   "clamp": "clamp",
   "divide": "divide",
+  "inc": "inc",
+  "dec": "dec",
   "fallback-number": "fallbackNumber",
   "is-in-range": "isInRange",
   "percent": "percent",

docs/pages/number/dec.mdx

@@ -0,0 +1,22 @@
+# dec
+
+Decrements the given number by 1, or by a specified step. Useful for counters and mathematical operations.
+
+### Import
+
+```typescript copy
+import { dec } from '@fullstacksjs/toolbox';
+```
+
+### Signature
+
+```typescript copy
+function dec(n: number, step?: number): number {}
+```
+
+### Examples
+
+```typescript copy
+dec(3)       // 2
+dec(3, 2)    // 1
+```

docs/pages/number/inc.mdx

@@ -0,0 +1,22 @@
+# inc
+
+Increments the given number by 1, or by a specified step. Useful for counters and mathematical operations.
+
+### Import
+
+```typescript copy
+import { inc } from '@fullstacksjs/toolbox';
+```
+
+### Signature
+
+```typescript copy
+function inc(n: number, step?: number): number {}
+```
+
+### Examples
+
+```typescript copy
+inc(3)       // 4
+inc(3, 2)    // 5
+```

src/number/dec.ts

@@ -0,0 +1,14 @@
+/**
+ * Decrements a number by 1 or a specified step.
+ *
+ * @param {number} n - The number to decrement.
+ * @param {number} [step=1] - The step size to decrement by. Defaults to 1.
+ * @returns {number} The decremented number.
+ *
+ * @example
+ * dec(3)       // 2
+ * dec(3, 2)    // 1
+ */
+export function dec(n: number, step: number = 1): number {
+  return n - step;
+}

src/number/des.spec.ts

@@ -0,0 +1,17 @@
+import { dec } from './dec';
+
+describe('dec', () => {
+  it('should decrement by 1 when no step is provided', () => {
+    expect(dec(2)).toBe(1);
+    expect(dec(5)).toBe(4);
+  });
+
+  it('should decrement by the given step', () => {
+    expect(dec(4, 2)).toBe(2);
+    expect(dec(8, 3)).toBe(5);
+  });
+
+  it('should handle negative steps correctly', () => {
+    expect(dec(5, -2)).toBe(7);
+  });
+});

src/number/inc.spec.ts

@@ -0,0 +1,17 @@
+import { inc } from './inc';
+
+describe('inc', () => {
+  it('should increment by 1 when no step is provided', () => {
+    expect(inc(0)).toBe(1);
+    expect(inc(5)).toBe(6);
+  });
+
+  it('should increment by the given step', () => {
+    expect(inc(0, 2)).toBe(2);
+    expect(inc(5, 3)).toBe(8);
+  });
+
+  it('should handle negative steps correctly', () => {
+    expect(inc(5, -2)).toBe(3);
+  });
+});

src/number/inc.ts

@@ -0,0 +1,14 @@
+/**
+ * Increments a number by 1 or a specified step.
+ *
+ * @param {number} n - The number to increment.
+ * @param {number} [step=1] - The step size to increment by. Defaults to 1.
+ * @returns {number} The incremented number.
+ *
+ * @example
+ * inc(3)       // 4
+ * inc(3, 2)    // 5
+ */
+export function inc(n: number, step: number = 1): number {
+  return n + step;
+}

src/number/index.ts

@@ -1,5 +1,7 @@
 export { clamp } from './clamp.ts';
 export { divide } from './divide.ts';
+export { inc } from './inc.ts';
+export { dec } from './dec.ts';
 export { fallbackNumber } from './fallbackNumber.ts';
 export { isInRange } from './isInRange.ts';
 export { percent } from './percent.ts';