Add primality tests.

Author: trekhleb

src/algorithms/math/primality-tests/__test__/primalityTest.js

@@ -16,6 +16,8 @@ export default function primalityTest(testFunction) {
   expect(testFunction(4)).toBeFalsy();
   expect(testFunction(6)).toBeFalsy();
   expect(testFunction(12)).toBeFalsy();
+  expect(testFunction(14)).toBeFalsy();
+  expect(testFunction(25)).toBeFalsy();
   expect(testFunction(192)).toBeFalsy();
   expect(testFunction(200)).toBeFalsy();
   expect(testFunction(400)).toBeFalsy();

src/algorithms/math/primality-tests/trialDivision.js

@@ -18,7 +18,7 @@ export default function trialDivision(number) {
 
   // If there is no dividers up to square root of n then there is no higher dividers as well.
   const dividerLimit = Math.sqrt(number);
-  for (let divider = 3; divider < dividerLimit; divider += 2) {
+  for (let divider = 3; divider <= dividerLimit; divider += 2) {
     if (number % divider === 0) {
       return false;
     }