Fix #7: Make sure the displayed output on failures is human readable

astorije · Nov 14, 2015 · 08edf4a · 08edf4a
1 parent 39540ff
commit 08edf4a
Show file tree

Hide file tree

Showing 2 changed files with 25 additions and 5 deletions.
diff --git a/chai-immutable.js b/chai-immutable.js
@@ -101,9 +101,10 @@
         if (obj && obj instanceof Collection) {
           this.assert(
             Immutable.is(obj, collection),
-            'expected #{this} to equal #{exp}',
-            'expected #{this} to not equal #{exp}',
-            collection
+            'expected #{act} to equal #{exp}',
+            'expected #{act} to not equal #{exp}',
+            collection.toString(),
+            obj.toString()
           );
         }
         else _super.apply(this, arguments);

diff --git a/test/test.js b/test/test.js
@@ -22,8 +22,9 @@ var Stack = Immutable.Stack;
  * Test helper to check that a given function (wrapping the assertion) will
  * fail.
  */
-function fail(fn) {
-  expect(fn).to.throw(chai.AssertionError);
+function fail(fn, msg) {
+  if (msg !== undefined) expect(fn).to.throw(chai.AssertionError, msg);
+  else expect(fn).to.throw(chai.AssertionError);
 }
 
 describe('chai-immutable (' + typeEnv + ')', function () {
@@ -123,6 +124,15 @@ describe('chai-immutable (' + typeEnv + ')', function () {
         expect([]).to.not.equal(List());
       });
 
+      // See https://github.com/astorije/chai-immutable/issues/7
+      it('should display a helpful failure output on big objects', function () {
+        var actual = new Map({ foo: 'foo foo foo foo foo foo foo foo' });
+        var expected = new Map({ bar: 'bar bar bar bar bar bar bar bar' });
+        fail(function () {
+          expect(actual).to.equal(expected);
+        }, /(foo ?){8}.+(bar ?){8}/);
+      });
+
       it('should fail given a non-Immutable value', function () {
         fail(function () { expect([]).to.equal(List()); });
       });
@@ -522,6 +532,15 @@ describe('chai-immutable (' + typeEnv + ')', function () {
         assert.equal(3, '3');
       });
 
+      // See https://github.com/astorije/chai-immutable/issues/7
+      it('should display a helpful failure output on big objects', function () {
+        var actual = new Map({ foo: 'foo foo foo foo foo foo foo foo' });
+        var expected = new Map({ bar: 'bar bar bar bar bar bar bar bar' });
+        fail(function () {
+          assert.equal(actual, expected);
+        }, /(foo ?){8}.+(bar ?){8}/);
+      });
+
       it('should fail given a non-Immutable value', function () {
         fail(function () { assert.equal([], List()); });
       });