Merge pull request #10 from Qix-/fix-bluebird

Add ability to modify .stack

.gitignore

@@ -2,3 +2,5 @@
 /node_modules/
 npm-debug.log
 /coverage/
+yarn.lock
+yarn-error.log

index.js

@@ -51,20 +51,28 @@ var errorEx = function errorEx(name, properties) {
 			}
 		});
 
+		var overwrittenStack = null;
+
 		var stackDescriptor = Object.getOwnPropertyDescriptor(this, 'stack');
 		var stackGetter = stackDescriptor.get;
 		var stackValue = stackDescriptor.value;
 		delete stackDescriptor.value;
 		delete stackDescriptor.writable;
 
+		stackDescriptor.set = function (newstack) {
+			overwrittenStack = newstack;
+		};
+
 		stackDescriptor.get = function () {
-			var stack = (stackGetter)
-				? stackGetter.call(this).split(/\r?\n+/g)
-				: stackValue.split(/\r?\n+/g);
+			var stack = (overwrittenStack || ((stackGetter)
+				? stackGetter.call(this)
+				: stackValue)).split(/\r?\n+/g);
 
 			// starting in Node 7, the stack builder caches the message.
 			// just replace it.
-			stack[0] = this.name + ': ' + this.message;
+			if (!overwrittenStack) {
+				stack[0] = this.name + ': ' + this.message;
+			}
 
 			var lineCount = 1;
 			for (var key in properties) {

test/test.coffee

@@ -124,3 +124,31 @@ describe 'helpers', ->
       err.fileName = '/a/b/c/foo.txt'
       testLine = err.stack.toString().split(/\r?\n/g)[1]
       testLine.should.equal '    in /a/b/c/foo.txt'
+
+describe 'bluebird support', ->
+  it 'should pass the bluebird stack write test', ->
+    bluebirdPropertyWritable = (obj, prop)->
+        descriptor = Object.getOwnPropertyDescriptor(obj, prop)
+        return !!(!descriptor || descriptor.writable || descriptor.set)
+
+    TestError = errorEx 'TestError', fileName: errorEx.line 'in %s'
+    err = new TestError 'error'
+    err_native = new Error 'hello'
+
+    (bluebirdPropertyWritable err_native, 'stack').should.be.ok()
+    (bluebirdPropertyWritable err, 'stack').should.be.ok()
+
+  it 'should allow the stack to be set while preserving custom properties', ->
+    TestError = errorEx 'TestError', fileName: errorEx.line 'in %s'
+
+    err = new TestError 'error'
+    err.fileName = '/a/b/c/foo.txt'
+    testLine = err.stack.toString().split(/\r?\n/g)[1]
+    testLine.should.equal '    in /a/b/c/foo.txt'
+
+    err.stack = 'TestError: overridden error\n    at null:1:1'
+    err.stack.toString().should.equal 'TestError: overridden error\n    in /a/b/c/foo.txt\n    at null:1:1'
+
+    err.stack = null
+    testLine = err.stack.toString().split(/\r?\n/g)[1]
+    testLine.should.equal '    in /a/b/c/foo.txt'