Fixed eslint problem with BigInt. It's also good for its use with webpack/babel

.eslintrc.json

@@ -23,5 +23,8 @@
             "error",
             "always"
         ]
+    },
+    "globals": {
+        "BigInt": "readonly"
     }
 }

src/main.js

@@ -9,7 +9,7 @@
  */
 const abs = function (a) {
     a = BigInt(a);
-	return (a >= 0n) ? a : -a;
+    return (a >= BigInt(0)) ? a : -a;
 };
 
 /**
@@ -23,15 +23,15 @@ const abs = function (a) {
 const gcd = function (a, b) {
     a = abs(a);
     b = abs(b);
-	let shift = 0n;
-	while (!((a | b) & 1n)) {
-		a >>= 1n;
-		b >>= 1n;
+    let shift = BigInt(0);
+    while (!((a | b) & BigInt(1))) {
+        a >>= BigInt(1);
+        b >>= BigInt(1);
         shift++;
     }
-	while (!(a & 1n)) a >>= 1n;
+    while (!(a & BigInt(1))) a >>= BigInt(1);
     do {
-		while (!(b & 1n)) b >>= 1n;
+        while (!(b & BigInt(1))) b >>= BigInt(1);
         if (a > b) {
             let x = a;
             a = b;
@@ -88,12 +88,12 @@ const toZn = function (a, n) {
 const eGcd = function (a, b) {
     a = BigInt(a);
     b = BigInt(b);
-	let x = 0n;
-	let y = 1n;
-	let u = 1n;
-	let v = 0n;
+    let x = BigInt(0);
+    let y = BigInt(1);
+    let u = BigInt(1);
+    let v = BigInt(0);
 
-	while (a !== 0n) {
+    while (a !== BigInt(0)) {
         let q = b / a;
         let r = b % a;
         let m = x - (u * q);
@@ -109,7 +109,7 @@ const eGcd = function (a, b) {
         b: b,
         x: x,
         y: y
-	}
+    };
 };
 
 /**
@@ -122,7 +122,7 @@ const eGcd = function (a, b) {
  */
 const modInv = function (a, n) {
     let egcd = eGcd(a, n);
-	if (egcd.b !== 1n) {
+    if (egcd.b !== BigInt(1)) {
         return null; // modular inverse does not exist
     } else {
         return toZn(egcd.x, n);
@@ -142,15 +142,15 @@ const modPow = function (a, b, n) {
     n = BigInt(n);
     a = toZn(a, n);
     b = BigInt(b);
-	if (b < 0n) {
+    if (b < BigInt(0)) {
         return modInv(modPow(a, abs(b), n), n);
     }
-	let result = 1n;
+    let result = BigInt(1);
     let x = a;
     while (b > 0) {
-		var leastSignificantBit = b % 2n;
-		b = b / 2n;
-		if (leastSignificantBit == 1n) {
+        var leastSignificantBit = b % BigInt(2);
+        b = b / BigInt(2);
+        if (leastSignificantBit == BigInt(1)) {
             result = result * x;
             result = result % n;
         }