Increasing Throws error message verbosity

'cause we actually want to know what was thrown.

lib/chai/core/assertions.js

@@ -892,7 +892,8 @@ module.exports = function (chai, _) {
 
     var thrown = false
       , desiredError = null
-      , name = null;
+      , name = null
+      , thrownError = null;
 
     if (arguments.length === 0) {
       errMsg = null;
@@ -926,8 +927,8 @@ module.exports = function (chai, _) {
       if (constructor) {
         this.assert(
             err instanceof constructor
-          , 'expected #{this} to throw ' + name + ' but a ' + err.name + ' was thrown'
-          , 'expected #{this} to not throw ' + name );
+          , 'expected #{this} to throw ' + name + ' but ' + _.inspect(err) + ' was thrown'
+          , 'expected #{this} to not throw ' + name + ' but ' + _.inspect(err) + ' was thrown');
         if (!errMsg) return this;
       }
       // next, check message
@@ -949,15 +950,20 @@ module.exports = function (chai, _) {
         return this;
       } else {
         thrown = true;
+        thrownError = err;
       }
     }
 
     var expectedThrown = name ? name : desiredError ? _.inspect(desiredError) : 'an error';
+    var actuallyGot = ''
+    if (thrown) {
+      actuallyGot = ' but ' + _.inspect(thrownError) + ' was thrown'
+    }
 
     this.assert(
         thrown === true
-      , 'expected #{this} to throw ' + expectedThrown
-      , 'expected #{this} to not throw ' + expectedThrown
+      , 'expected #{this} to throw ' + expectedThrown + actuallyGot
+      , 'expected #{this} to not throw ' + expectedThrown + actuallyGot
     );
   };
 

test/assert.js

@@ -418,7 +418,7 @@ suite('assert', function () {
 
     err(function () {
       assert.doesNotThrow(function() { throw new Error('foo'); });
-     }, 'expected [Function] to not throw an error');
+     }, 'expected [Function] to not throw an error but [Error: foo] was thrown');
   });
 
   test('ifError', function() {

test/expect.js

@@ -562,35 +562,35 @@ suite('expect', function () {
 
     err(function(){
       expect(badFn).to.not.throw();
-    }, "expected [Function] to not throw an error");
+    }, "expected [Function] to not throw an error but [Error: testing] was thrown");
 
     err(function(){
       expect(badFn).to.throw(ReferenceError);
-    }, "expected [Function] to throw ReferenceError but a Error was thrown");
+    }, "expected [Function] to throw ReferenceError but [Error: testing] was thrown");
 
     err(function(){
       expect(badFn).to.throw(specificError);
     }, "expected [Function] to throw [RangeError: boo] but [Error: testing] was thrown");
 
     err(function(){
       expect(badFn).to.not.throw(Error);
-    }, "expected [Function] to not throw Error");
+    }, "expected [Function] to not throw Error but [Error: testing] was thrown");
 
     err(function(){
       expect(refErrFn).to.not.throw(ReferenceError);
-    }, "expected [Function] to not throw ReferenceError");
+    }, "expected [Function] to not throw ReferenceError but [ReferenceError: hello] was thrown");
 
     err(function(){
       expect(badFn).to.throw(PoorlyConstructedError);
-    }, "expected [Function] to throw PoorlyConstructedError but a Error was thrown");
+    }, "expected [Function] to throw PoorlyConstructedError but [Error: testing] was thrown");
 
     err(function(){
       expect(ickyErrFn).to.not.throw(PoorlyConstructedError);
-    }, "expected [Function] to not throw PoorlyConstructedError");
+    }, "expected [Function] to not throw PoorlyConstructedError but { name: 'PoorlyConstructedError' } was thrown");
 
     err(function(){
       expect(ickyErrFn).to.throw(ReferenceError);
-    }, "expected [Function] to throw ReferenceError but a PoorlyConstructedError was thrown");
+    }, "expected [Function] to throw ReferenceError but { name: 'PoorlyConstructedError' } was thrown");
 
     err(function(){
       expect(specificErrFn).to.throw(new ReferenceError('eek'));

test/should.js

@@ -530,35 +530,35 @@ suite('should', function() {
 
     err(function(){
       (badFn).should.not.throw();
-    }, "expected [Function] to not throw an error");
+    }, "expected [Function] to not throw an error but [Error: testing] was thrown");
 
     err(function(){
       (badFn).should.throw(ReferenceError);
-    }, "expected [Function] to throw ReferenceError but a Error was thrown");
+    }, "expected [Function] to throw ReferenceError but [Error: testing] was thrown");
 
     err(function(){
       (badFn).should.throw(specificError);
     }, "expected [Function] to throw [RangeError: boo] but [Error: testing] was thrown");
 
     err(function(){
       (badFn).should.not.throw(Error);
-    }, "expected [Function] to not throw Error");
+    }, "expected [Function] to not throw Error but [Error: testing] was thrown");
 
     err(function(){
       (refErrFn).should.not.throw(ReferenceError);
-    }, "expected [Function] to not throw ReferenceError");
+    }, "expected [Function] to not throw ReferenceError but [ReferenceError: hello] was thrown");
 
     err(function(){
       (badFn).should.throw(PoorlyConstructedError);
-    }, "expected [Function] to throw PoorlyConstructedError but a Error was thrown");
+    }, "expected [Function] to throw PoorlyConstructedError but [Error: testing] was thrown");
 
     err(function(){
       (ickyErrFn).should.not.throw(PoorlyConstructedError);
-    }, "expected [Function] to not throw PoorlyConstructedError");
+    }, "expected [Function] to not throw PoorlyConstructedError but { name: 'PoorlyConstructedError' } was thrown");
 
     err(function(){
       (ickyErrFn).should.throw(ReferenceError);
-    }, "expected [Function] to throw ReferenceError but a PoorlyConstructedError was thrown");
+    }, "expected [Function] to throw ReferenceError but { name: 'PoorlyConstructedError' } was thrown");
 
     err(function(){
       (specificErrFn).should.throw(new ReferenceError('eek'));