bn.js - npm Package Compare versions

Comparing version 4.7.0 to 4.8.0

package.json

 {
   "name": "bn.js",
-  "version": "4.7.0",
+  "version": "4.8.0",
   "description": "Big number implementation in pure javascript",
@@ -5,0 +5,0 @@ "main": "lib/bn.js",

README.md

@@ -22,2 +22,4 @@ # <img src="./logo.png" alt="bn.js" width="160" height="160" />
 
+**Note**: decimals are not supported in this library.
+
 ## Notation
@@ -77,2 +79,4 @@
 * `a.eq(b)` - `a` equals `b` (`n`)
+* `a.toTwos(width)` - convert to two's complement representation, where `width` is bit width
+* `a.fromTwos(width)` - convert from two's complement representation, where `width` is the bit width
 
@@ -79,0 +83,0 @@ ### Arithmetics

test/utils-test.js

@@ -263,2 +263,54 @@ /* global describe, it */
   });
+
+  describe('.fromTwos', function () {
+    it('should convert from two\'s complement to negative number', function () {
+      assert.equal(new BN('00000000', 16).fromTwos(32).toNumber(), 0);
+      assert.equal(new BN('00000001', 16).fromTwos(32).toNumber(), 1);
+      assert.equal(new BN('7fffffff', 16).fromTwos(32).toNumber(), 2147483647);
+      assert.equal(new BN('80000000', 16).fromTwos(32).toNumber(), -2147483648);
+      assert.equal(new BN('f0000000', 16).fromTwos(32).toNumber(), -268435456);
+      assert.equal(new BN('f1234567', 16).fromTwos(32).toNumber(), -249346713);
+      assert.equal(new BN('ffffffff', 16).fromTwos(32).toNumber(), -1);
+      assert.equal(new BN('fffffffe', 16).fromTwos(32).toNumber(), -2);
+      assert.equal(new BN('fffffffffffffffffffffffffffffffe', 16)
+        .fromTwos(128).toNumber(), -2);
+      assert.equal(new BN('ffffffffffffffffffffffffffffffff' +
+        'fffffffffffffffffffffffffffffffe', 16).fromTwos(256).toNumber(), -2);
+      assert.equal(new BN('ffffffffffffffffffffffffffffffff' +
+        'ffffffffffffffffffffffffffffffff', 16).fromTwos(256).toNumber(), -1);
+      assert.equal(new BN('7fffffffffffffffffffffffffffffff' +
+        'ffffffffffffffffffffffffffffffff', 16).fromTwos(256).toString(10),
+        new BN('5789604461865809771178549250434395392663499' +
+          '2332820282019728792003956564819967', 10).toString(10));
+      assert.equal(new BN('80000000000000000000000000000000' +
+        '00000000000000000000000000000000', 16).fromTwos(256).toString(10),
+        new BN('-578960446186580977117854925043439539266349' +
+          '92332820282019728792003956564819968', 10).toString(10));
+    });
+  });
+
+  describe('.toTwos', function () {
+    it('should convert from negative number to two\'s complement', function () {
+      assert.equal(new BN(0).toTwos(32).toString(16), '0');
+      assert.equal(new BN(1).toTwos(32).toString(16), '1');
+      assert.equal(new BN(2147483647).toTwos(32).toString(16), '7fffffff');
+      assert.equal(new BN('-2147483648', 10).toTwos(32).toString(16), '80000000');
+      assert.equal(new BN('-268435456', 10).toTwos(32).toString(16), 'f0000000');
+      assert.equal(new BN('-249346713', 10).toTwos(32).toString(16), 'f1234567');
+      assert.equal(new BN('-1', 10).toTwos(32).toString(16), 'ffffffff');
+      assert.equal(new BN('-2', 10).toTwos(32).toString(16), 'fffffffe');
+      assert.equal(new BN('-2', 10).toTwos(128).toString(16),
+        'fffffffffffffffffffffffffffffffe');
+      assert.equal(new BN('-2', 10).toTwos(256).toString(16),
+        'fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe');
+      assert.equal(new BN('-1', 10).toTwos(256).toString(16),
+        'ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff');
+      assert.equal(new BN('5789604461865809771178549250434395392663' +
+        '4992332820282019728792003956564819967', 10).toTwos(256).toString(16),
+        '7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff');
+      assert.equal(new BN('-578960446186580977117854925043439539266' +
+        '34992332820282019728792003956564819968', 10).toTwos(256).toString(16),
+        '8000000000000000000000000000000000000000000000000000000000000000');
+    });
+  });
 });

No alert changes

Improved metrics

Total package byte prevSize

159753

increased by2.45%

Lines of code

4505

increased by1.4%

Number of lines in readme file

215

increased by1.9%

No dependency changes