feat: string utils

Author: KatoakDR

electron/common/string/__tests__/is-blank.test.ts

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+import { describe, expect, it } from 'vitest';
+import { isBlank } from '../is-blank.js';
+
+describe('is-blank', () => {
+  it.each([undefined, null, '', '  ', '\n'])(
+    'returns true when string is `%s`q',
+    async (text: null | undefined | string) => {
+      expect(isBlank(text)).toBe(true);
+    }
+  );
+
+  it.each(['a', ' a', 'a ', ' a '])(
+    'returns false when string is `%s`',
+    async (text: string) => {
+      expect(isBlank(text)).toBe(false);
+    }
+  );
+});

electron/common/string/__tests__/is-empty.test.ts

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+import { describe, expect, it } from 'vitest';
+import { isEmpty } from '../is-empty.js';
+
+describe('is-empty', () => {
+  it.each([undefined, null, ''])(
+    'returns true when string is `%s`',
+    async (text: null | undefined | string) => {
+      expect(isEmpty(text)).toBe(true);
+    }
+  );
+
+  it.each(['a', ' a', 'a ', ' a ', '  ', '\n'])(
+    'returns false when string is `%s`',
+    async (text: string) => {
+      expect(isEmpty(text)).toBe(false);
+    }
+  );
+});

electron/common/string/is-blank.ts

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+import { isEmpty } from './is-empty.js';
+
+/**
+ * Returns true if the text is undefined, null, or is empty when trimmed.
+ * Whitespace characters are ignored.
+ *
+ * We use a type guard in result to hint that if this function returns false
+ * then the value cannot be null or undefined.
+ */
+export function isBlank(
+  text: string | null | undefined
+): text is null | undefined {
+  return isEmpty(text?.trim());
+}

electron/common/string/is-empty.ts

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+/**
+ * Returns true if the text is undefined, null, or empty string ('').
+ * Whitespace characters are considered non-empty.
+ *
+ * We use a type guard in result to hint that if this function returns false
+ * then the value cannot be null or undefined.
+ */
+export function isEmpty(
+  text: string | null | undefined
+): text is null | undefined {
+  return !text || text === '';
+}