feat: add read-float helper

Author: tada5hi

README.MD

@@ -12,6 +12,14 @@ This library simplifies reading, transforming, and requiring environment variabl
 **Table of Contents**
 - [Installation](#installation)
 - [Usage](#usage)
+  - [write](#write)
+  - [read](#read)
+  - [readArray](#read-array)
+  - [readBool](#read-bool)
+  - [readFloat](#read-float)
+  - [readInt](#read-int)
+  - [readNumber](#read-number)
+  - [readNumberArray](#read-number-array)
 - [Contributing](#contributing)
 - [License](#license)
 
@@ -80,8 +88,24 @@ readBool('bar', false); // boolean
 // false
 ```
 
+### Read Float
+The readFloat method makes it possible to read an environment variable as a float.
+A fallback value can be defined as the second argument.
+
+```typescript
+import { readFloat, write } from 'envix';
+
+write('foo', '1');
+
+readFloat('foo'); // number | undefined
+// 1.0
+
+readFloat('bar', 2.0); // number
+// 2.0
+```
+
 ### Read Int
-The readBool method makes it possible to read an environment variable as a boolean.
+The readInt method makes it possible to read an environment variable as a integer.
 A fallback value can be defined as the second argument.
 
 ```typescript
@@ -97,7 +121,7 @@ readInt('bar', 2); // number
 ```
 
 ### Read Number
-The readBool method makes it possible to read an environment variable as a number.
+The readNumber method makes it possible to read an environment variable as a number.
 A fallback value can be defined as the second argument.
 
 ```typescript

src/index.ts

@@ -5,6 +5,7 @@ export * from './read';
 export * from './read-array';
 export * from './read-bool';
 export * from './read-int';
+export * from './read-float';
 export * from './read-number';
 export * from './read-number-array';
 export * from './write';

src/read-float.ts

@@ -0,0 +1,13 @@
+import { read } from './read';
+import { toFloat } from './utils';
+
+export function readFloat(key: string) : number | undefined;
+export function readFloat<T>(key: string, alt: T) : T | number;
+export function readFloat<T>(key: string, alt?: T) : any {
+    const value = read(key) as any;
+    if (typeof value !== 'undefined') {
+        return toFloat(value) ?? alt;
+    }
+
+    return alt;
+}

src/utils/float.ts

@@ -0,0 +1,8 @@
+export function toFloat(value: any) : number | undefined {
+    const num = Number.parseFloat(value);
+    if (Number.isNaN(num) || Number.isNaN(value)) {
+        return undefined;
+    }
+
+    return num;
+}

src/utils/index.ts

@@ -1,3 +1,4 @@
 export * from './bool';
+export * from './float';
 export * from './int';
 export * from './number';

test/unit/read-float.spec.ts

@@ -0,0 +1,23 @@
+import { readFloat, write } from '../../src';
+
+describe('src/read-float.ts', () => {
+    it('should read float env', () => {
+        write('foo', '1');
+
+        let result = readFloat('foo');
+        expect(result).toEqual(1.0);
+
+        write('foo', 'foo');
+
+        result = readFloat('foo');
+        expect(result).toBeUndefined();
+
+        write('foo', undefined);
+
+        result = readFloat('foo', 2.0);
+        expect(result).toEqual(2.0);
+
+        result = readFloat('foo');
+        expect(result).toBeUndefined();
+    });
+});

test/unit/read-int.spec.ts

@@ -1,7 +1,7 @@
 import { readInt, write } from '../../src';
 
 describe('src/read-int.ts', () => {
-    it('should read number env', () => {
+    it('should read int env', () => {
         write('foo', '1.0');
 
         let result = readInt('foo');