Change output for empty strings, null and undefined #9

Author: fabian-hiller

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All notable changes to the library will be documented in this file.
 
+## vX.X.X (Month DD, YYYY)
+
+- Change output for empty strings, `'null'` and `'undefined'` (issue #9)
+
 ## v0.5.0 (December 14, 2023)
 
 - Add `FormDataInfo` type to global exports

src/regex.ts

@@ -3,6 +3,11 @@
  */
 export const DIGIT_REGEX = /^\d+$/u;
 
+/**
+ * Number regex.
+ */
+export const NUMBER_REGEX = /^-?\d*(\.\d+)?$/u;
+
 /**
  * [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) date regex.
  */

src/utils/getFieldBoolean/getFieldBoolean.test.ts

@@ -0,0 +1,36 @@
+import { describe, expect, test } from 'vitest';
+import { getFieldBoolean } from './getFieldBoolean.ts';
+
+describe('getFieldBoolean', () => {
+  test('should decode booleans', () => {
+    // Emtpy string
+    expect(getFieldBoolean('')).toBeNull();
+
+    // "null" string
+    expect(getFieldBoolean('null')).toBeNull();
+
+    // "undefined" string
+    expect(getFieldBoolean('undefined')).toBeUndefined();
+
+    // "true" string
+    expect(getFieldBoolean('true')).toBe(true);
+
+    // "false" string
+    expect(getFieldBoolean('false')).toBe(false);
+
+    // "1" string
+    expect(getFieldBoolean('1')).toBe(true);
+
+    // "0" string
+    expect(getFieldBoolean('0')).toBe(false);
+
+    // "on" string
+    expect(getFieldBoolean('on')).toBe(true);
+
+    // "off" string
+    expect(getFieldBoolean('off')).toBe(false);
+
+    // Otherwise
+    expect(getFieldBoolean('test')).toBe(true);
+  });
+});

src/utils/getFieldBoolean/getFieldBoolean.ts

@@ -0,0 +1,21 @@
+/**
+ * Returns the decoded boolean of a field.
+ *
+ * @param value The field value.
+ *
+ * @returns The decoded boolean.
+ */
+export function getFieldBoolean(value: FormDataEntryValue) {
+  // Null
+  if (!value || value === 'null') {
+    return null;
+  }
+
+  // Undefined
+  if (value === 'undefined') {
+    return undefined;
+  }
+
+  // Otherwise
+  return !(value === 'false' || value === 'off' || value === '0');
+}

src/utils/getFieldBoolean/index.ts

@@ -0,0 +1 @@
+export * from './getFieldBoolean.ts';

src/utils/getFieldDate/getFieldDate.test.ts

@@ -6,6 +6,12 @@ describe('getFieldDate', () => {
     // Emtpy string
     expect(getFieldDate('')).toBeNull();
 
+    // Null string
+    expect(getFieldDate('null')).toBeNull();
+
+    // Undefined string
+    expect(getFieldDate('undefined')).toBeUndefined();
+
     // Date (yyyy-mm-dd)
     expect(getFieldDate('2023-10-04')).toEqual(
       new Date('2023-10-04T00:00:00.000Z')

src/utils/getFieldDate/getFieldDate.ts

@@ -15,11 +15,16 @@ import {
  * @returns The decoded date.
  */
 export function getFieldDate(value: string) {
-  // Empty string
-  if (!value) {
+  // Null
+  if (!value || value === 'null') {
     return null;
   }
 
+  // Undefined
+  if (value === 'undefined') {
+    return undefined;
+  }
+
   // Date (yyyy-mm-dd)
   if (ISO_DATE_REGEX.test(value)) {
     return new Date(`${value}T00:00:00.000Z`);

src/utils/getFieldNumber/getFieldNumber.test.ts

@@ -0,0 +1,32 @@
+import { describe, expect, test } from 'vitest';
+import { getFieldNumber } from './getFieldNumber.ts';
+
+describe('getFieldNumber', () => {
+  test('should decode numbers', () => {
+    // Emtpy string
+    expect(getFieldNumber('')).toBeNull();
+
+    // "null" string
+    expect(getFieldNumber('null')).toBeNull();
+
+    // "undefined" string
+    expect(getFieldNumber('undefined')).toBeUndefined();
+
+    // Number strings
+    expect(getFieldNumber('123')).toBe(123);
+    expect(getFieldNumber('-123')).toBe(-123);
+    expect(getFieldNumber('1.23')).toBe(1.23);
+    expect(getFieldNumber('-1.23')).toBe(-1.23);
+    expect(getFieldNumber('12.3')).toBe(12.3);
+    expect(getFieldNumber('-12.3')).toBe(-12.3);
+
+    // Date string
+    expect(getFieldNumber('2023-10-04')).toBe(1696377600000);
+    expect(getFieldNumber('2024-02-11T21:54:10.851Z')).toBe(1707688450851);
+
+    // Otherwise
+    expect(getFieldNumber('1,234.56')).toBeNaN();
+    expect(getFieldNumber('Invalid Date')).toBeNaN();
+    expect(getFieldNumber('abc')).toBeNaN();
+  });
+});

src/utils/getFieldNumber/getFieldNumber.ts

@@ -0,0 +1,29 @@
+import { NUMBER_REGEX } from '../../regex.ts';
+import { getFieldDate } from '../getFieldDate/index.ts';
+
+/**
+ * Returns the decoded number of a field.
+ *
+ * @param value The field value.
+ *
+ * @returns The decoded number.
+ */
+export function getFieldNumber(value: string) {
+  // Null
+  if (!value || value === 'null') {
+    return null;
+  }
+
+  // Undefined
+  if (value === 'undefined') {
+    return undefined;
+  }
+
+  // Number
+  if (NUMBER_REGEX.test(value)) {
+    return Number(value);
+  }
+
+  // Date
+  return getFieldDate(value)!.getTime();
+}

src/utils/getFieldNumber/index.ts

@@ -0,0 +1 @@
+export * from './getFieldNumber.ts';