chai-bn - npm Package Compare versions

Comparing version 0.1.0-alpha.2 to 0.1.0-beta.0

chai-bn.js

@@ -11,2 +11,3 @@ module.exports = function (BN) {
   return function (chai, utils) {
+    // The 'bignumber' property sets the 'bignumber' flag, enabling the custom overrides
     chai.Assertion.addProperty('bignumber', function () {
@@ -16,2 +17,3 @@ utils.flag(this, 'bignumber', true);
 
+    // BN objects created using different (compatible) instances of BN can be used via BN.isBN()
     const isBN = function (object) {
@@ -22,6 +24,7 @@ return object instanceof BN || BN.isBN(object);
     const convert = function (value) {
-      if (typeof value === 'string') {
+      if (isBN(value)) {
+        return value;
+      } else if (typeof value === 'string') {
         return new BN(value);
-      } else if (isBN(value)) {
-        return value;
+      // BN also supports conversion from e.g. JavaScript numbers, but only for small values. We disable that entirely
       } else {
@@ -33,7 +36,7 @@ new chai.Assertion(value).assert(false,
 
-    const assertBN = function (value) {
+    const assertIsBN = function (value) {
       if (!isBN(value)) {
         new chai.Assertion(value).assert(
           false,
-          'expected #{value} to be an instance of BN'
+          'expected #{act} to be an instance of BN'
         );
@@ -43,14 +46,16 @@ }
 
-    const overwriteMethods = function (names, fn) {
-      function overwriteMethod (original) {
+    // Overwrites the assertion performed by multiple methods (which should be aliases) with a new function. Prior to
+    // calling said function, we assert that the actual value is a BN, and attempt to convert the expected value.
+    const overwriteMethods = function (methodNames, newAssertion) {
+      function overwriteMethod (originalAssertion) {
         return function (value) {
           if (utils.flag(this, 'bignumber')) {
-
             const actual = this._obj;
-            assertBN(actual);
+            assertIsBN(actual);
 
             const expected = convert(value);
-            fn.apply(this, [expected, actual]);
+
+            newAssertion.apply(this, [expected, actual]);
           } else {
-            original.apply(this, arguments);
+            originalAssertion.apply(this, arguments);
           }
@@ -60,17 +65,19 @@ };
 
-      names.forEach(name =>
-        chai.Assertion.overwriteMethod(name, overwriteMethod)
+      methodNames.forEach(methodName =>
+        chai.Assertion.overwriteMethod(methodName, overwriteMethod)
       );
     };
 
-    const overwriteProperties = function (names, fn) {
-      function overwriteProperty (original) {
+    // Overwrites the assertion performed by multiple properties (which should be aliases) with a new function. Prior to
+    // calling said function, we assert that the actual value is a BN.
+    const overwriteProperties = function (propertyNames, newAssertion) {
+      function overwriteProperty (originalAssertion) {
         return function () {
           if (utils.flag(this, 'bignumber')) {
             const actual = this._obj;
-            assertBN(actual);
+            assertIsBN(actual);
 
-            fn.apply(this, [actual]);
+            newAssertion.apply(this, [actual]);
           } else {
-            original.call(this);
+            originalAssertion.call(this);
           }
@@ -80,4 +87,4 @@ };
 
-      names.forEach(name =>
-        chai.Assertion.overwriteProperty(name, overwriteProperty)
+      propertyNames.forEach(propertyName =>
+        chai.Assertion.overwriteProperty(propertyName, overwriteProperty)
       );
@@ -84,0 +91,0 @@ };

package.json

 {
   "name": "chai-bn",
-  "version": "0.1.0-alpha.2",
+  "version": "0.1.0-beta.0",
   "description": "Chai assertions for comparing arbitrary-precision integers using the bignumber.js library",
@@ -5,0 +5,0 @@ "main": "chai-bn.js",

README.md

@@ -6,3 +6,3 @@ # chai-bn
 
-Chai assertions for comparing arbitrary-precision integers using the [bn.js](https://github.com/indutny/bn.js) library. Forked from [chai-bignumber](https://github.com/asmarques/chai-bignumber), which uses the [bignumber.js](https://github.com/MikeMcl/bignumber.js) library.
+[`Chai`](https://www.chaijs.com/) assertions for comparing arbitrary-precision integers using the [bn.js](https://github.com/indutny/bn.js) library. Forked from [chai-bignumber](https://github.com/asmarques/chai-bignumber), which uses the [bignumber.js](https://github.com/MikeMcl/bignumber.js) library.
 
@@ -27,3 +27,3 @@ ## Installation
 
-The following assertion methods are provided and will override the existing builtin assertions if the `bignumber` property is explicitly set as part of the assertion chain:
+The following assertion methods are provided and will override the existing builtin assertions if the `bignumber` property is set as part of the assertion chain:
 - equal/equals/eq
@@ -39,4 +39,6 @@ - above/gt/greaterThan
 
-Actual values (i.e. the values being asserted) must be instances of `BN`. Expected values (i.e. the values the actual value is expected to match) may be instances of either `BN` or `string` which can be converted into a valid number. Only BDD style (`expect` or `should`) assertions are supported.
+Actual values (i.e. the values being asserted) **must** be instances of `BN`. Expected values (i.e. the values the actual value is expected to match) may be instances of either `BN` or `string` which can be converted into a valid number. This is a key difference with [chai-bignumber](https://github.com/asmarques/chai-bignumber), which automatically converts JavaScript numbers and strings to `BigNumber` instances for both actual and expected values.
 
+Only BDD style (`expect` or `should`) assertions are supported.
+
 ## Examples
@@ -50,5 +52,5 @@
 
-actual.should.be.bignumber.equal(expected);
-expect(actual).to.be.bignumber.at.most(expected);
-(new BN('1000')).should.be.bignumber.lessThan('2000');
+actual.should.be.a.bignumber.that.equals(expected);
+expect(actual).to.be.a.bignumber.that.is.at.most(expected);
+(new BN('1000')).should.be.a.bignumber.that.is.lessThan('2000');
 ```
@@ -59,8 +61,10 @@
 ```javascript
-(new BN('-100')).should.be.negative;
-expect(new BN('1').sub(new BN('1'))).to.be.zero;
+(new BN('-100')).should.be.a.bignumber.that.is.negative;
+expect(new BN('1').sub(new BN('1'))).to.be.a.bignumber.that.is.zero;
 ```
 
+Some `Chai` properties (e.g. the `that.is` chain) have no effect other than increasing readability, and can be dropped if less verbosity is desired.
+
 ## License
 
 [MIT](LICENSE)

No alert changes

Improved metrics

Total package byte prevSize

9575

increased by15.99%

Lines of code

143

increased by5.15%

Number of lines in readme file

66

increased by6.45%

No dependency changes