feat: ✨ add isCuid validation and types (#11)

Co-authored-by: Ben Wilson <[email protected]>

cuid.d.ts

@@ -1,5 +1,6 @@
 declare module '@bugsnag/cuid' {
-    function cuid(): string
+    export function fingerprint(): string
+    export function isCuid(value: unknown): value is string
 
-    export default cuid
+    export default function cuid(): string
 }

index.js

@@ -11,6 +11,7 @@
  */
 
 var fingerprint = require('./lib/fingerprint.js');
+var isCuid = require('./lib/is-cuid.js');
 var pad = require('./lib/pad.js');
 
 var c = 0,
@@ -38,7 +39,7 @@ function cuid () {
     // timestamp
     // warning: this exposes the exact date and time
     // that the uid was created.
-    timestamp = (new Date().getTime()).toString(base),
+    timestamp = new Date().getTime().toString(base),
 
     // Prevent same-machine collisions.
     counter = pad(safeCounter().toString(base), blockSize),
@@ -55,5 +56,6 @@ function cuid () {
 }
 
 cuid.fingerprint = fingerprint;
+cuid.isCuid = isCuid;
 
 module.exports = cuid;

lib/is-cuid.js

@@ -0,0 +1,8 @@
+/**
+ * Check the provided value is a valid device id
+ * @param {unknown} value
+ * @returns
+ */
+module.exports = function isCuid (value) {
+    return typeof value === 'string' && (/^c[a-z0-9]{20,32}$/).test(value);
+};

test/test.js

@@ -46,3 +46,22 @@ describe('cuid collisions', function () {
     expect(collisionTest(cuid)).toBe(true);
   });
 });
+
+describe('isCuid()', function () {
+  it('should return true for generated cuids', function () {
+    expect(cuid.isCuid(cuid())).toBe(true);
+  });
+
+  it('should return false for strings that are too short', function () {
+    expect(cuid.isCuid('cuidistooshort')).toBe(false);
+  });
+
+  it('should return false for strings that are too long', function () {
+    expect(cuid.isCuid('cuidismorethan32characterssoisnotvalid')).toBe(false);
+  });
+
+  it('should return false for strings that do not match the format', function () {
+    expect(cuid.isCuid('doesnotbeginwithacsoisinvalid')).toBe(false);
+    expect(cuid.isCuid('contains-invalid-characters')).toBe(false);
+  });
+});