how to write tests

test/testing.md

@@ -0,0 +1,159 @@
+# How to write tests
+
+1. You can have a separate function for faktory manager setup that you can call in func main(), for e.g.
+
+``` go
+func faktoryManagerSetup() error {
+	// create faktory manager
+	mgr = worker.NewManager()
+
+	// set logger to the app's logger
+	mgr.Logger = app.Log
+
+	// NewPool creates a new Pool object through which multiple clients
+	// are managed.
+	pool, err := faktory.NewPool(5)
+	if err != nil {
+		return err
+	}
+
+	mgr.Pool = pool
+
+	mgr.Use(func(ctx context.Context, job *faktory.Job, next func(ctx context.Context) error) error {
+		app.Log.Infof("Starting work on job %s of type %s\n", job.Jid, job.Type)
+		err := next(ctx)
+		app.Log.Infof("Finished work on job %s with error %v\n", job.Jid, err)
+		return err
+	})
+
+	// use up to N goroutines to execute jobs
+	mgr.Concurrency = 20
+
+	// pull jobs from these queues, in this order of precedence
+	mgr.ProcessStrictPriorityQueues("critical", "default", "bulk")
+
+	// register a job type and the handler
+	// jobs will go into the "default" queue
+	mgr.Register("UpdateWiki", UpdateWikiHandler)
+
+	// register another job type
+	mgr.Register("UpdateReleaseStatus", UpdateReleaseStatusHandler)
+
+	return nil
+}
+```
+
+2. Now, when you are writing a test for a function where you enqueue a faktory job, you can call this function.
+
+``` go
+func TestMain(m *testing.M) {
+    testSetUp()
+    faktoryManagerSetup()
+    exitCode := m.Run()
+    os.Exit(exitCode)
+
+```
+
+3. Table driven testing is a very good way of avoiding duplicate code, and it works really well in this case. Let's take an example:
+
+``` go
+var payload []byte
+func (suite *FunctionalTestSuite) TestJob_Errors() {
+    uniqueID := uuid.NewUUID()
+    testCases := []struct {
+        name                string
+        hasError            bool
+        expectedError       string
+        jobEnqueued         bool
+    }{
+        {
+            "Malformed Payload",
+            true,
+            "unable to process payload",
+            false,
+        },
+        {
+            "Empty Payload",
+            true,
+            "empty payload",
+            false,
+        },
+        {
+            "Empty Metadata",
+            true,
+            "empty metadata",
+            false,
+        },
+    }
+
+    for _, testCase := range testCases {
+        fn := func() {
+            payload = []byte("test payload")
+			pool, _ := faktory.NewPool(5)
+			perf := worker.NewTestExecutor(pool)
+            someJob := faktory.NewJob("UpdateWiki", uniqueID, payload)
+
+            // now call the function that actually creates a job in your flow
+            err = suite.processSomePayload(payload)
+
+            if testCase.jobEnqueued && testCase.hasError {
+				err = perf.Execute(someJob, func(ctx context.Context, args ...interface{}) error {
+					return fmt.Errorf(testCase.expectedError)
+				})
+				suite.require.Error(err)
+            }
+
+            if !testCase.jobEnqueued && testCase.hasError {
+				err = perf.Execute(someJob, func(ctx context.Context, args ...interface{}) error {
+					return fmt.Errorf(testCase.expectedError)
+				})
+				suite.require.Error(err)
+				suite.assert.Contains(err.Error(), testCase.expectedError)
+
+			} else {
+				err = perf.Execute(someJob, func(ctx context.Context, args ...interface{}) error {
+					return nil
+				})
+				suite.NoError(err)
+			}
+            }
+		suite.Run(testCase.name, fn)
+	}
+}
+```
+
+Another example for testing the handler response:
+
+``` go
+func (suite *FunctionalTestSuite) TestJob_Errors() {
+    uniqueID := uuid.NewUUID()
+    testCases := []struct {
+        name                string
+        hasError            bool
+        jobEnqueued         bool
+    }{
+        {
+            "Success",
+            true,
+            true,
+        },
+    }
+
+    for _, testCase := range testCases {
+		fn := func() {
+			pool, _ := faktory.NewPool(5)
+			perf := worker.NewTestExecutor(pool)
+			var i interface{} = []string{uniqueID.String(), "payload"}
+			jobArgs := []interface{}{i}
+			someJob := faktory.NewJob("UpdateWiki", jobArgs...)
+
+    	    err = perf.Execute(someJob, UpdateWikiHandler)
+            suite.require.NotNil(err)
+        }
+
+        suite.Run(testCase.name, fn)
+    }
+
+}
+
+```