chai-as-promised - npm Package Compare versions

Comparing version 4.2.0 to 4.3.0

lib/chai-as-promised.js

@@ -29,2 +29,6 @@ (function () {
 
+    chaiAsPromised.transformAsserterArgs = function (values) {
+        return values;
+    };
+
     function chaiAsPromised(chai, utils) {
@@ -304,2 +308,5 @@ var Assertion = chai.Assertion;
                 utils.flag(assertion, "eventually", false);
+
+                return args ? chaiAsPromised.transformAsserterArgs(args) : args;
+            }).then(function (args) {
                 asserter.apply(assertion, args);
@@ -306,0 +313,0 @@

package.json

@@ -11,3 +11,3 @@ {
     ],
-    "version": "4.2.0",
+    "version": "4.3.0",
     "author": "Domenic Denicola <[e-mail]> (https://domenic.me)",
@@ -14,0 +14,0 @@ "license": "WTFPL",

README.md

@@ -48,3 +48,3 @@ <a href="http://promisesaplus.com/">
 // becomes
-return promiseFor(2 + 2).should.eventually.equal(4);
+return Promise.resolve(2 + 2).should.eventually.equal(4);
 
@@ -55,3 +55,3 @@
 // becomes
-return expect(promiseFor({ foo: "bar" })).to.eventually.have.property("foo");
+return expect(Promise.resolve({ foo: "bar" })).to.eventually.have.property("foo");
 ```
@@ -78,3 +78,3 @@
 // becomes
-return assert.eventually.equal(promiseFor(2 + 2), 4, "This had better be true, eventually");
+return assert.eventually.equal(Promise.resolve(2 + 2), 4, "This had better be true, eventually");
 ```
@@ -126,2 +126,33 @@
 
+### Transforming Arguments to the Asserters
+
+Another advanced customization hook Chai as Promised allows is if you want to transform the arguments to the
+asserters, possibly asynchronously. Here is a toy example:
+
+```js
+chaiAsPromised.transformAsserterArgs = function (args) {
+    return args.map(function (x) { return x + 1; });
+}
+
+Promise.resolve(2).should.eventually.equal(2); // will now fail!
+Promise.resolve(2).should.eventually.equal(3); // will now pass!
+```
+
+The transform can even be asynchronous, returning a promise for an array instead of an array directly. An example
+of that might be using `Promise.all` so that an array of promises becomes a promise for an array. If you do that,
+then you can compare promises against other promises using the asserters:
+
+```js
+// This will normally fail, since within() only works on numbers.
+Promise.resolve(2).should.eventually.be.within(Promise.resolve(1), Promise.resolve(6));
+
+chaiAsPromised.transformAsserterArgs = function (args) {
+    return Promise.all(args);
+};
+
+// But now it will pass, since we transformed the array of promises for numbers into
+// (a promise for) an array of numbers
+Promise.resolve(2).should.eventually.be.within(Promise.resolve(1), Promise.resolve(6));
+```
+
 ### Compatibility
@@ -128,0 +159,0 @@

New alerts

Unidentified License

License

(Experimental) Something that seems like a license was found, but its contents could not be matched with a known license

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

28653

increased by8.33%

Number of package files

4

increased by33.33%

Lines of code

319

increased by1.59%

Number of lines in readme file

272

increased by12.86%

Worsened metrics

Number of low license alerts

1

increased byInfinity%

License quality

80

decreased by-20%

No dependency changes