Add Math.modExp and a Panic library (#3298)

Co-authored-by: Hadrien Croubois <hadrien.croubois@gmail.com>
Co-authored-by: ernestognw <ernestognw@gmail.com>

test/utils/math/Math.test.js

@@ -141,6 +141,24 @@ describe('Math', function () {
     });
   });
 
+  describe('tryModExp', function () {
+    it('is correctly returning true and calculating modulus', async function () {
+      const base = 3n;
+      const exponent = 200n;
+      const modulus = 50n;
+
+      expect(await this.mock.$tryModExp(base, exponent, modulus)).to.deep.equal([true, base ** exponent % modulus]);
+    });
+
+    it('is correctly returning false when modulus is 0', async function () {
+      const base = 3n;
+      const exponent = 200n;
+      const modulus = 0n;
+
+      expect(await this.mock.$tryModExp(base, exponent, modulus)).to.deep.equal([false, 0n]);
+    });
+  });
+
   describe('max', function () {
     it('is correctly detected in both position', async function () {
       await testCommutative(this.mock.$max, 1234n, 5678n, max(1234n, 5678n));
@@ -222,7 +240,7 @@ describe('Math', function () {
     });
   });
 
-  describe('muldiv', function () {
+  describe('mulDiv', function () {
     it('divide by 0', async function () {
       const a = 1n;
       const b = 1n;
@@ -234,9 +252,8 @@ describe('Math', function () {
       const a = 5n;
       const b = ethers.MaxUint256;
       const c = 2n;
-      await expect(this.mock.$mulDiv(a, b, c, Rounding.Floor)).to.be.revertedWithCustomError(
-        this.mock,
-        'MathOverflowedMulDiv',
+      await expect(this.mock.$mulDiv(a, b, c, Rounding.Floor)).to.be.revertedWithPanic(
+        PANIC_CODES.ARITHMETIC_UNDER_OR_OVERFLOW,
       );
     });
 
@@ -336,6 +353,24 @@ describe('Math', function () {
     }
   });
 
+  describe('modExp', function () {
+    it('is correctly calculating modulus', async function () {
+      const base = 3n;
+      const exponent = 200n;
+      const modulus = 50n;
+
+      expect(await this.mock.$modExp(base, exponent, modulus)).to.equal(base ** exponent % modulus);
+    });
+
+    it('is correctly reverting when modulus is zero', async function () {
+      const base = 3n;
+      const exponent = 200n;
+      const modulus = 0n;
+
+      await expect(this.mock.$modExp(base, exponent, modulus)).to.be.revertedWithPanic(PANIC_CODES.DIVISION_BY_ZERO);
+    });
+  });
+
   describe('sqrt', function () {
     it('rounds down', async function () {
       for (const rounding of RoundingDown) {