From 3c4019a15443d0ba593022171e950a13f9f2ae41 Mon Sep 17 00:00:00 2001
From: Baris Aydek <baris.aydek@gmail.com>
Date: Tue, 25 Feb 2025 19:28:28 +0300
Subject: [PATCH] nip54 normalizeIdentifier function

---
 index.ts      |  1 +
 jsr.json      |  1 +
 nip54.test.ts | 42 ++++++++++++++++++++++++++++++++++++++++++
 nip54.ts      | 19 +++++++++++++++++++
 package.json  |  5 +++++
 5 files changed, 68 insertions(+)
 create mode 100644 nip54.test.ts
 create mode 100644 nip54.ts

diff --git a/index.ts b/index.ts
index 2113e78..69aef00 100644
--- a/index.ts
+++ b/index.ts
@@ -21,6 +21,7 @@ export * as nip39 from './nip39.ts'
 export * as nip42 from './nip42.ts'
 export * as nip44 from './nip44.ts'
 export * as nip47 from './nip47.ts'
+export * as nip54 from './nip54.ts'
 export * as nip57 from './nip57.ts'
 export * as nip59 from './nip59.ts'
 export * as nip98 from './nip98.ts'
diff --git a/jsr.json b/jsr.json
index 43f1070..e8d44aa 100644
--- a/jsr.json
+++ b/jsr.json
@@ -34,6 +34,7 @@
     "./nip44": "./nip44.ts",
     "./nip46": "./nip46.ts",
     "./nip49": "./nip49.ts",
+    "./nip54": "./nip54.ts",
     "./nip57": "./nip57.ts",
     "./nip58": "./nip58.ts",
     "./nip59": "./nip59.ts",
diff --git a/nip54.test.ts b/nip54.test.ts
new file mode 100644
index 0000000..f01a90d
--- /dev/null
+++ b/nip54.test.ts
@@ -0,0 +1,42 @@
+import { describe, test, expect } from 'bun:test'
+import { normalizeIdentifier } from './nip54.ts'
+
+describe('normalizeIdentifier', () => {
+  test('converts to lowercase', () => {
+    expect(normalizeIdentifier('HELLO')).toBe('hello')
+    expect(normalizeIdentifier('MixedCase')).toBe('mixedcase')
+  })
+
+  test('trims whitespace', () => {
+    expect(normalizeIdentifier('  hello  ')).toBe('hello')
+    expect(normalizeIdentifier('\thello\n')).toBe('hello')
+  })
+
+  test('normalizes Unicode to NFKC form', () => {
+    // é can be represented as single char é (U+00E9) or e + ´ (U+0065 U+0301)
+    expect(normalizeIdentifier('café')).toBe('café')
+    expect(normalizeIdentifier('cafe\u0301')).toBe('café')
+  })
+
+  test('replaces non-alphanumeric characters with hyphens', () => {
+    expect(normalizeIdentifier('hello world')).toBe('hello-world')
+    expect(normalizeIdentifier('user@example.com')).toBe('user-example-com')
+    expect(normalizeIdentifier('$special#chars!')).toBe('-special-chars-')
+  })
+
+  test('preserves numbers', () => {
+    expect(normalizeIdentifier('user123')).toBe('user123')
+    expect(normalizeIdentifier('2fast4you')).toBe('2fast4you')
+  })
+
+  test('handles multiple consecutive special characters', () => {
+    expect(normalizeIdentifier('hello!!!world')).toBe('hello---world')
+    expect(normalizeIdentifier('multiple   spaces')).toBe('multiple---spaces')
+  })
+
+  test('handles Unicode letters from different scripts', () => {
+    expect(normalizeIdentifier('привет')).toBe('привет')
+    expect(normalizeIdentifier('こんにちは')).toBe('こんにちは')
+    expect(normalizeIdentifier('مرحبا')).toBe('مرحبا')
+  })
+})
diff --git a/nip54.ts b/nip54.ts
new file mode 100644
index 0000000..badcc86
--- /dev/null
+++ b/nip54.ts
@@ -0,0 +1,19 @@
+export function normalizeIdentifier(name: string): string {
+  // Trim and lowercase
+  name = name.trim().toLowerCase()
+
+  // Normalize Unicode to NFKC form
+  name = name.normalize('NFKC')
+
+  // Convert to array of characters and map each one
+  return Array.from(name)
+    .map(char => {
+      // Check if character is letter or number using Unicode ranges
+      if (/\p{Letter}/u.test(char) || /\p{Number}/u.test(char)) {
+        return char
+      }
+
+      return '-'
+    })
+    .join('')
+}
diff --git a/package.json b/package.json
index c5b2235..a6e0bce 100644
--- a/package.json
+++ b/package.json
@@ -173,6 +173,11 @@
       "require": "./lib/cjs/nip49.js",
       "types": "./lib/types/nip49.d.ts"
     },
+    "./nip54": {
+      "import": "./lib/esm/nip54.js",
+      "require": "./lib/cjs/nip54.js",
+      "types": "./lib/types/nip54.d.ts"
+    },
     "./nip57": {
       "import": "./lib/esm/nip57.js",
       "require": "./lib/cjs/nip57.js",