From d413b63fd8d1190d2cd15f073d48efb71808b7de Mon Sep 17 00:00:00 2001
From: "Kent C. Dodds" <kent@doddsfamily.us>
Date: Tue, 28 Mar 2017 07:09:12 -0600
Subject: [PATCH] WIP: getting close to a working version

---
 .../__snapshots__/failures-test.js.snap       | 98 +++++++++++++------
 packages/jest-jasmine2/package.json           |  1 +
 packages/jest-jasmine2/src/jasmine/Spec.js    | 24 ++++-
 3 files changed, 92 insertions(+), 31 deletions(-)

diff --git a/integration_tests/__tests__/__snapshots__/failures-test.js.snap b/integration_tests/__tests__/__snapshots__/failures-test.js.snap
index 2a33d89ecfa1..a394cc634b05 100644
--- a/integration_tests/__tests__/__snapshots__/failures-test.js.snap
+++ b/integration_tests/__tests__/__snapshots__/failures-test.js.snap
@@ -57,12 +57,11 @@ Object {
   "rest": " FAIL  __tests__/assertion-count-test.js
   ● .assertions() › throws
 
-    expect(received).toBeTruthy()
-    
-    Expected value to be truthy, instead received
-      false
+    Error
+      Error: expect(received).toBeTruthy()
       
-      at Object.throws (__tests__/assertion-count-test.js:14:17)
+      Expected value to be truthy, instead received
+        false
 
   ● .assertions() › throws
 
@@ -74,12 +73,11 @@ Object {
 
   ● .assertions() › throws on redeclare of assertion count
 
-    expect(received).toBeTruthy()
-    
-    Expected value to be truthy, instead received
-      false
+    Error
+      Error: expect(received).toBeTruthy()
       
-      at Object.redeclare (__tests__/assertion-count-test.js:18:17)
+      Expected value to be truthy, instead received
+        false
 
   ● .assertions() › throws on assertion
 
@@ -109,51 +107,91 @@ Object {
   "rest": " FAIL  __tests__/node-assertion-error-test.js
   ● assert
 
-    AssertionError: false == true
-      
-      at Object.test (__tests__/node-assertion-error-test.js:16:3)
+    Error
+      AssertionError: false == true
 
   ● assert with a message
 
-    AssertionError: this is a message
-      
-      at Object.test (__tests__/node-assertion-error-test.js:20:3)
+    Error
+      AssertionError: this is a message
 
   ● assert.ok
 
-    AssertionError: false == true
-      
-      at Object.test (__tests__/node-assertion-error-test.js:24:10)
+    Error
+      AssertionError: false == true
 
   ● assert.ok with a message
 
-    AssertionError: this is a message
-      
-      at Object.test (__tests__/node-assertion-error-test.js:28:10)
+    Error
+      AssertionError: this is a message
 
   ● assert.equal
 
-    AssertionError: 1 == 2
+    Error
+      expect(received).toBe(expected)
       
-      at Object.test (__tests__/node-assertion-error-test.js:32:10)
+      Expected value to be (using ===):
+        2
+      Received:
+        1
 
   ● assert.equal with a message
 
-    AssertionError: this is a message
+    Error
+      expect(received).toBe(expected)
       
-      at Object.test (__tests__/node-assertion-error-test.js:36:10)
+      Expected value to be (using ===):
+        2
+      Received:
+        1
 
   ● assert.deepEqual
 
-    AssertionError: { a: { b: { c: 5 } } } deepEqual { a: { b: { c: 6 } } }
+    Error
+      expect(received).toBe(expected)
+      
+      Expected value to be (using ===):
+        {\\"a\\": {\\"b\\": {\\"c\\": 6}}}
+      Received:
+        {\\"a\\": {\\"b\\": {\\"c\\": 5}}}
+      
+      Difference:
       
-      at Object.test (__tests__/node-assertion-error-test.js:40:10)
+      - Expected
+      + Received
+      
+      Object {
+          \\"a\\": Object {
+            \\"b\\": Object {
+      -       \\"c\\": 6,
+      +       \\"c\\": 5,
+            },
+          },
+        }
 
   ● assert.deepEqual with a message
 
-    AssertionError: this is a message
+    Error
+      expect(received).toBe(expected)
+      
+      Expected value to be (using ===):
+        {\\"a\\": {\\"b\\": {\\"c\\": 7}}}
+      Received:
+        {\\"a\\": {\\"b\\": {\\"c\\": 5}}}
+      
+      Difference:
+      
+      - Expected
+      + Received
       
-      at Object.test (__tests__/node-assertion-error-test.js:44:10)
+      Object {
+          \\"a\\": Object {
+            \\"b\\": Object {
+      -       \\"c\\": 7,
+      +       \\"c\\": 5,
+            },
+          },
+        }
 
   ✕ assert
   ✕ assert with a message
diff --git a/packages/jest-jasmine2/package.json b/packages/jest-jasmine2/package.json
index a4220b2f6ea2..b215c928a86c 100644
--- a/packages/jest-jasmine2/package.json
+++ b/packages/jest-jasmine2/package.json
@@ -9,6 +9,7 @@
   "main": "build/index.js",
   "dependencies": {
     "graceful-fs": "^4.1.11",
+    "jest-diff": "^19.0.0",
     "jest-matcher-utils": "^19.0.0",
     "jest-matchers": "^19.0.0",
     "jest-message-util": "^19.0.0",
diff --git a/packages/jest-jasmine2/src/jasmine/Spec.js b/packages/jest-jasmine2/src/jasmine/Spec.js
index e9403e869547..b70f45767ea6 100644
--- a/packages/jest-jasmine2/src/jasmine/Spec.js
+++ b/packages/jest-jasmine2/src/jasmine/Spec.js
@@ -32,6 +32,12 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 /* eslint-disable sort-keys */
 'use strict';
 
+const diff = require('jest-diff');
+const {
+  matcherHint,
+  printReceived,
+  printExpected,
+} = require('jest-matcher-utils');
 const ExpectationFailed = require('../ExpectationFailed');
 const expectationResultFactory = require('../expectationResultFactory');
 
@@ -121,10 +127,26 @@ Spec.prototype.onException = function onException(e) {
     return;
   }
 
+  const {expected, actual} = e || {};
+  let message;
+  if (expected && actual) {
+    const diffString = diff(expected, actual, {
+      expand: this.expand,
+    });
+    message = matcherHint('.toBe') +
+      '\n\n' +
+      `Expected value to be (using ===):\n` +
+      `  ${printExpected(expected)}\n` +
+      `Received:\n` +
+      `  ${printReceived(actual)}` +
+      (diffString ? `\n\nDifference:\n\n${diffString}` : '');
+  }
+
   this.addExpectationResult(
     false,
     {
-      matcherName: '',
+      matcherName: 'blah',
+      message,
       passed: false,
       expected: '',
       actual: '',