better error messages with stack traces

Author: James Halliday

lib/render.js

@@ -81,6 +81,14 @@ function encodeResult (res, count) {
             output += inner + 'expected: ' + ex + '\n';
             output += inner + 'actual:   ' + ac + '\n';
         }
+        if (res.operator === 'error' && res.actual && res.actual.stack) {
+            var lines = String(res.actual.stack).split('\n');
+            output += inner + 'stack:\n';
+            output += inner + '  ' + lines[0] + '\n';
+            for (var i = 1; i < lines.length; i++) {
+                output += inner + lines[i] + '\n';
+            }
+        }
 
         output += outer + '...\n';
     }

lib/test.js

@@ -184,7 +184,7 @@ Test.prototype.error
 = Test.prototype.iferror
 = function (err, msg, extra) {
     this._assert(!err, {
-        message : defined(msg, err.message),
+        message : defined(msg, String(err)),
         operator : 'error',
         actual : err,
         extra : extra

test/throw.js

@@ -21,7 +21,7 @@ tap.test('throw test', function (tt) {
             'TAP version 13',
             'thrower',
             { id: 1, ok: true, name: 'should be equal' },
-            { id: 2, ok: false, name: 'rawr' },
+            { id: 2, ok: false, name: 'Error: rawr' },
             'tests 2',
             'pass  1',
             'fail  1',