normalizeString

Author: ogroppo

.vscode/settings.json

@@ -9,4 +9,5 @@
   "[typescript]": {
     "editor.defaultFormatter": "dbaeumer.vscode-eslint"
   },
+  "vitest.disableWorkspaceWarning": true,
 }

CHANGELOG.md

@@ -1,5 +1,11 @@
 # deverything
 
+## 4.5.0
+
+### Minor Changes
+
+- normalizeString
+
 ## 4.4.1
 
 ### Patch Changes

package.json

@@ -1,6 +1,6 @@
 {
   "name": "deverything",
-  "version": "4.4.1",
+  "version": "4.5.0",
   "description": "Everything you need for Dev",
   "main": "./dist/index.js",
   "module": "./dist/index.mjs",

src/helpers/index.ts

@@ -32,6 +32,7 @@ export * from "./moveToFirst";
 export * from "./moveToIndex";
 export * from "./moveToLast";
 export * from "./normalizeNumber";
+export * from "./normalizeString";
 export * from "./objectDiff";
 export * from "./omit";
 export * from "./parseDate";

src/helpers/normalizeString.test.ts

@@ -0,0 +1,112 @@
+import { describe, expect, test } from "vitest";
+import { normalizeString } from "./normalizeString";
+
+describe("normalizeString", () => {
+  test("removes diacritical marks", () => {
+    expect(normalizeString("Crème  brûlée")).toBe("creme brulee");
+    expect(normalizeString(" niñO")).toBe("nino");
+    expect(normalizeString("café")).toBe("cafe");
+    expect(normalizeString("naïve")).toBe("naive");
+    expect(normalizeString("résumé")).toBe("resume");
+    expect(normalizeString("Zürich")).toBe("zurich");
+    expect(normalizeString("Москва")).toBe("москва"); // Cyrillic remains
+    expect(normalizeString("北京")).toBe("北京"); // Chinese remains
+  });
+
+  test("converts to lowercase", () => {
+    expect(normalizeString("HELLO WORLD")).toBe("hello world");
+    expect(normalizeString("CamelCase")).toBe("camelcase");
+    expect(normalizeString("UPPERCASE")).toBe("uppercase");
+    expect(normalizeString("MiXeD CaSe")).toBe("mixed case");
+  });
+
+  test("normalizes spaces", () => {
+    expect(normalizeString("  multiple   spaces  ")).toBe("multiple spaces");
+    expect(normalizeString("\t\ttabs\t\there\t")).toBe("tabs here");
+    expect(normalizeString("line\nbreaks\r\nhere")).toBe("line breaks here");
+    expect(normalizeString("   leading and trailing   ")).toBe(
+      "leading and trailing"
+    );
+  });
+
+  test("handles special characters", () => {
+    expect(normalizeString("[email protected]")).toBe("[email protected]");
+    expect(normalizeString("price: $99.99")).toBe("price: $99.99");
+    expect(normalizeString("100%")).toBe("100%");
+    expect(normalizeString("C++ & Java")).toBe("c++ & java");
+    expect(normalizeString("hello-world_test")).toBe("hello-world_test");
+  });
+
+  test("handles empty and whitespace-only strings", () => {
+    expect(normalizeString("")).toBe("");
+    expect(normalizeString("   ")).toBe("");
+    expect(normalizeString("\t\n\r")).toBe("");
+    expect(normalizeString("\u00A0")).toBe(""); // non-breaking space
+  });
+
+  test("handles unicode normalization", () => {
+    expect(normalizeString("fi")).toBe("fi"); // ligature remains
+    expect(normalizeString("½")).toBe("½"); // fraction remains
+    expect(normalizeString("™")).toBe("™"); // trademark remains
+    expect(normalizeString("😀")).toBe("😀"); // emoji remains
+  });
+
+  test("handles combined diacritics", () => {
+    expect(normalizeString("àáâãäå")).toBe("aaaaaa");
+    expect(normalizeString("èéêë")).toBe("eeee");
+    expect(normalizeString("ìíîï")).toBe("iiii");
+    expect(normalizeString("òóôõö")).toBe("ooooo");
+    expect(normalizeString("ùúûü")).toBe("uuuu");
+    expect(normalizeString("ýÿ")).toBe("yy");
+    expect(normalizeString("ñ")).toBe("n");
+    expect(normalizeString("ç")).toBe("c");
+  });
+
+  test("handles mixed content", () => {
+    expect(normalizeString("  José's Café - 50% OFF!  ")).toBe(
+      "jose's cafe - 50% off!"
+    );
+    expect(normalizeString("Björk & Sigur Rós")).toBe("bjork & sigur ros");
+    expect(normalizeString("Düsseldorf → München")).toBe(
+      "dusseldorf → munchen"
+    );
+    expect(normalizeString("  Naïve\tRésumé\n2024  ")).toBe(
+      "naive resume 2024"
+    );
+  });
+
+  test("preserves numbers and punctuation", () => {
+    expect(normalizeString("123.456")).toBe("123.456");
+    expect(normalizeString("[email protected]")).toBe("[email protected]");
+    expect(normalizeString("hello, world!")).toBe("hello, world!");
+    expect(normalizeString("question?")).toBe("question?");
+    expect(normalizeString("[brackets] {braces} (parens)")).toBe(
+      "[brackets] {braces} (parens)"
+    );
+  });
+
+  test("handles very long strings", () => {
+    const longString = "À".repeat(1000) + "  " + "É".repeat(1000);
+    const expected = "a".repeat(1000) + " " + "e".repeat(1000);
+    expect(normalizeString(longString)).toBe(expected);
+  });
+
+  test("handles invisible characters", () => {
+    expect(normalizeString("hello\u200Bworld")).toBe("hello world"); // zero-width space
+    expect(normalizeString("test\u2028text")).toBe("test text"); // line separator
+    expect(normalizeString("foo\u2029bar")).toBe("foo bar"); // paragraph separator
+    expect(normalizeString("data\u0000value")).toBe("data value"); // null character
+  });
+
+  test("real-world examples", () => {
+    expect(normalizeString("Señorita María González")).toBe(
+      "senorita maria gonzalez"
+    );
+    expect(normalizeString("François Müller")).toBe("francois muller");
+    expect(normalizeString("Łukasz Żółć")).toBe("łukasz zołc"); // Polish letters remain
+    expect(normalizeString("Renée O'Connor")).toBe("renee o'connor");
+    expect(normalizeString("  Dr.   José   García-López  ")).toBe(
+      "dr. jose garcia-lopez"
+    );
+  });
+});

src/helpers/normalizeString.ts

@@ -0,0 +1,8 @@
+import { cleanSpaces } from "./cleanSpaces";
+
+export const normalizeString = (str: string): string => {
+  return cleanSpaces(str)
+    .normalize("NFD") // split letters and diacritics
+    .replace(/[\u0300-\u036f]/g, "") // remove diacritical marks
+    .toLowerCase(); // lowercase
+};