From c6a13bd6d2435ec5940ab3757ff70babf9ed15da Mon Sep 17 00:00:00 2001
From: Brian Cavalier <brian@hovercraftstudios.com>
Date: Thu, 3 Jan 2013 15:08:41 -0500
Subject: [PATCH] See #10. Initial method/func tracer aspect.  API needs work,
 but guts are there

---
 aspect/trace.js           | 76 +++++++++++++++++++++++++++++++++++++++
 test/aspect/trace-test.js | 68 +++++++++++++++++++++++++++++++++++
 test/buster.js            |  2 +-
 3 files changed, 145 insertions(+), 1 deletion(-)
 create mode 100644 aspect/trace.js
 create mode 100644 test/aspect/trace-test.js

diff --git a/aspect/trace.js b/aspect/trace.js
new file mode 100644
index 0000000..8ed972c
--- /dev/null
+++ b/aspect/trace.js
@@ -0,0 +1,76 @@
+/**
+ * trace
+ * @author: brian@hovercraftstudios.com
+ */
+(function(define) {
+define(function(require) {
+
+	var meld, joinpoint, padding, simpleReporter;
+
+	meld = require('../meld');
+	joinpoint = meld.joinpoint;
+
+	// Padding characters for indenting traces
+	padding =  '........';
+
+	// 2^12 padding = 4096. If you need more stack than that,
+	// you probably have bigger problems!
+	for(var i=0; i<9; i++) {
+		padding += padding;
+	}
+
+	simpleReporter = {
+		enter: function(info, depth) {
+			console.log(indent(depth) + info.method, 'CALL', info.args);
+		},
+		success: function(info, depth) {
+			console.log(indent(depth) + info.method, 'RETURN', info.result);
+		},
+		fail: function(info, depth) {
+			console.warn(indent(depth) + info.method, 'THROW', info.exception);
+		}
+	};
+
+	return {
+		createAspect: createTraceAspect,
+		publicMethods: /^[^_]/,
+		allMethods: /.+/
+	};
+
+	function createTraceAspect(reporter) {
+		var depth;
+
+		depth = 0;
+
+		if(!reporter) {
+			reporter = simpleReporter;
+		}
+
+		return {
+			before: function() {
+				// Always increase depth
+				depth += 1;
+				reporter.enter && reporter.enter(joinpoint(), depth);
+			},
+
+			afterReturning: function() {
+				reporter.success && reporter.success(joinpoint(), depth);
+			},
+
+			afterThrowing: function() {
+				reporter.fail && reporter.fail(joinpoint(), depth);
+			},
+
+			after: function() {
+				// Always decrease depth
+				depth -= 1;
+			}
+		};
+	}
+
+	function indent(depth) {
+		return padding.slice(0, depth-1);
+	}
+
+});
+}(typeof define === 'function' ? define : function(factory) { module.exports = factory(require); }));
diff --git a/test/aspect/trace-test.js b/test/aspect/trace-test.js
new file mode 100644
index 0000000..6a0bc17
--- /dev/null
+++ b/test/aspect/trace-test.js
@@ -0,0 +1,68 @@
+(function(buster, meld, trace) {
+'use strict';
+
+var assert, refute, sentinel;
+
+assert = buster.assert;
+refute = buster.refute;
+
+sentinel = {};
+
+buster.testCase('aspect/trace', {
+
+	'should call enter upon entering advised method': function() {
+		var spy, advised, reporter;
+
+		spy = this.spy();
+		advised = { method: spy };
+		reporter = { enter: this.spy() };
+
+		meld.add(advised, 'method', trace.createAspect(reporter));
+
+		advised.method(sentinel);
+
+		assert.calledOnceWith(spy, sentinel);
+		assert.calledOnce(reporter.enter);
+	},
+
+	'should call success upon returning from advised method': function() {
+		var advised, reporter;
+
+		advised = {
+			method: function() { refute.called(reporter.success); }
+		};
+		reporter = { success: this.spy() };
+
+		meld.add(advised, 'method', trace.createAspect(reporter));
+
+		advised.method();
+
+		assert.calledOnce(reporter.success);
+	},
+
+	'should call fail upon throwing from advised method': function() {
+		var advised, reporter;
+
+		advised = {
+			method: function() {
+				refute.called(reporter.fail);
+				throw sentinel;
+			}
+		};
+		reporter = { fail: this.spy() };
+
+		meld.add(advised, 'method', trace.createAspect(reporter));
+
+		assert.exception(function() {
+			advised.method();
+			assert.calledOnce(reporter.fail);
+		});
+	}
+
+});
+
+})(
+	require('buster'),
+	require('../../meld'),
+	require('../../aspect/trace')
+);
\ No newline at end of file
diff --git a/test/buster.js b/test/buster.js
index 0f2927d..32dcb98 100644
--- a/test/buster.js
+++ b/test/buster.js
@@ -1,4 +1,4 @@
 exports['meld:node'] = {
 	environment: 'node',
-	tests: ['*.js']
+	tests: ['**/*.js']
 };