fix(@toss/validators): Increase the accuracy of verification for isBirthDate6 (toss#420)

* fix(@toss/validators): Increase the accuracy of verification

* test(@toss/validators): add test case

* fix: catch 2000y bug

* refactor: change from magic number to constant variable

* test: split test case

* refactor: change constant variable name

* refactor(@toss/validators): use proper library(date-fns)

Author: po4tion

.pnp.cjs

@@ -26,7 +26,8 @@
     "typecheck": "tsc --noEmit"
   },
   "dependencies": {
-    "@toss/utils": "workspace:^1.4.6"
+    "@toss/utils": "workspace:^1.4.6",
+    "date-fns": "^2.25.0"
   },
   "devDependencies": {
     "@babel/core": "^7",

packages/common/validators/package.json

@@ -1,16 +1,33 @@
 import { isBirthDate6 } from './is-birth-date-6';
 
 describe('isBirthDate6', () => {
-  it('should return `true` if given value is valid', () => {
-    expect(isBirthDate6('960729')).toEqual(true);
-    expect(isBirthDate6('961231')).toEqual(true);
-    expect(isBirthDate6('000101')).toEqual(true);
+  describe('when given value is a valid string of 6 digits', () => {
+    it('should return true for valid value', () => {
+      expect(isBirthDate6('960729')).toEqual(true);
+      expect(isBirthDate6('961231')).toEqual(true);
+      expect(isBirthDate6('000101')).toEqual(true);
+      expect(isBirthDate6('000229')).toEqual(true);
+    });
   });
-  it('should return `false` if given value is not valid', () => {
-    expect(isBirthDate6('19960729')).toEqual(false);
-    expect(isBirthDate6('foobar')).toEqual(false);
-    expect(isBirthDate6('000000')).toEqual(false);
-    expect(isBirthDate6('960732')).toEqual(false);
-    expect(isBirthDate6('')).toEqual(false);
+
+  describe('when given value is not a valid string of 6 digits', () => {
+    it('should return false for invalid formats', () => {
+      expect(isBirthDate6('19960729')).toEqual(false);
+      expect(isBirthDate6('foobar')).toEqual(false);
+      expect(isBirthDate6('000000')).toEqual(false);
+      expect(isBirthDate6('')).toEqual(false);
+    });
+
+    it('should return false for out of range values', () => {
+      expect(isBirthDate6('960732')).toEqual(false);
+      expect(isBirthDate6('951301')).toEqual(false);
+      expect(isBirthDate6('970000')).toEqual(false);
+      expect(isBirthDate6('950431')).toEqual(false);
+    });
+
+    it('should return false for leap year edge cases', () => {
+      expect(isBirthDate6('990229')).toEqual(false);
+      expect(isBirthDate6('210029')).toEqual(false);
+    });
   });
 });

packages/common/validators/src/validators/is-birth-date-6.spec.ts

@@ -1,5 +1,8 @@
 /** @tossdocs-ignore */
+import { isValid, parse } from 'date-fns';
+
 export function isBirthDate6(birthDate: string) {
-  const re = /^[0-9]{2}(?:0[1-9]|1[0-2])(?:0[1-9]|[1,2][0-9]|3[0,1])$/;
-  return re.test(birthDate);
+  const parsed = parse(birthDate, 'yyMMdd', new Date());
+
+  return isValid(parsed);
 }

packages/common/validators/src/validators/is-birth-date-6.ts

@@ -6275,6 +6275,7 @@ __metadata:
     "@types/node": ^14.14.41
     babel-jest: ^29
     concurrently: ^4.1.0
+    date-fns: ^2.25.0
     jest: ^29.0.1
     jest-environment-jsdom: ^29
     rollup: ^2.77.0