1 files changed, 42 insertions, 0 deletions

diff --git a/packages/forms/src/input/scorePassword.ts b/packages/forms/src/input/scorePassword.ts
new file mode 100644
index 000000000..bdad7aa28
--- /dev/null
+++ b/packages/forms/src/input/scorePassword.ts
@@ -0,0 +1,42 @@
+interface ILetters {
+  [key: string]: number;
+}
+
+interface IVariations {
+  [index: string]: boolean;
+  digits: boolean;
+  lower: boolean;
+  nonWords: boolean;
+  upper: boolean;
+}
+
+export default function scorePasswordFunc(password: string): number {
+  let score: number = 0;
+  if (!password) {
+    return score;
+  }
+
+  // award every unique letter until 5 repetitions
+  const letters: ILetters = {};
+  for (let i = 0; i < password.length; i += 1) {
+    letters[password[i]] = (letters[password[i]] || 0) + 1;
+    score += 5.0 / letters[password[i]];
+  }
+
+  // bonus points for mixing it up
+  const variations: IVariations = {
+    digits: /\d/.test(password),
+    lower: /[a-z]/.test(password),
+    nonWords: /\W/.test(password),
+    upper: /[A-Z]/.test(password),
+  };
+
+  let variationCount = 0;
+  Object.keys(variations).forEach((key) => {
+    variationCount += (variations[key] === true) ? 1 : 0;
+  });
+
+  score += (variationCount - 1) * 10;
+
+  return Math.round(score);
+}