add emitting of errors

mlrawlings · Jul 5, 2016 · c2f5db9 · c2f5db9
1 parent cbdb722
commit c2f5db9
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Showing 2 changed files with 37 additions and 5 deletions.
diff --git a/src/util.js b/src/util.js
@@ -12,10 +12,15 @@ var wrapFn = exports.wrapFn = function(fn, options, instrumitter) {
 
         var args = data.arguments
         var before = process.hrtime()
-        var result = fn.apply(this, args)
-        var after = process.hrtime()
-
-        handleReturnEvent(data, options, instrumitter, result, before, after)
+        try {
+            var result = fn.apply(this, args)
+            var after = process.hrtime()
+            handleReturnEvent(data, options, instrumitter, result, before, after)
+        } catch(error) {
+            var after = process.hrtime()
+            handleReturnEventError(data, options, instrumitter, error, before, after)
+            throw error
+        }
         handlePromiseEvent(data, options, instrumitter)
 
         return result
@@ -46,6 +51,16 @@ var handleReturnEvent = exports.handleReturnEvent = function(data, options, inst
     }
 }
 
+var handleReturnEventError = exports.handleReturnEventError = function(data, options, instrumitter, error, before, after) {
+    data.time = hrTimeToMilliSeconds(before)
+    data.return = { error, time:hrTimeToMilliSeconds(after) }
+    data.return.elapsed = data.return.time - data.time
+
+    if(options.return) {
+        instrumitter.emit(options.fn+':return', data)
+    }
+}
+
 var handleCallbackEvent = exports.handleCallbackEvent = function(data, options, instrumitter) {
     var args = data.arguments
     var callback = args[args.length-1]

diff --git a/test.js b/test.js
@@ -146,5 +146,22 @@ describe('instrumitter', () => {
         var httpEvents2 = instrumitter('http').watch('request', 'get')
         expect(httpEvents2).to.equal(httpEvents)
     })
-    it('should catch errors thrown by a function')
+    it('should catch errors thrown by a function', done => {
+        var object = {
+            test:function() {
+                throw new Error('test')
+            }
+        }
+
+        var objectEvents = instrumitter(object).watch('test')
+        objectEvents.once('test:return', fn => {
+            expect(fn.arguments).to.eql(['abc'])
+            expect(fn.return.value).to.not.exist
+            expect(fn.return.error.message).to.equal('test')
+            expect(fn.return.elapsed).to.be.above(0)
+            done()
+        })
+
+        expect(() => object.test('abc')).to.throw(/test/)
+    })
 })