Add error propagation and test todos for watcher

libraries/shared/watcher.go

@@ -56,12 +56,17 @@ func (watcher *Watcher) Execute() error {
 
 	// TODO Handle start and end numbers in transformers?
 	missingHeaders, err := shared.MissingHeaders(0, -1, watcher.DB, notCheckedSQL)
+	if err != nil {
+		log.Error("Fetching of missing headers failed in watcher!")
+		return err
+	}
 
 	for _, header := range missingHeaders {
 		// TODO Extend FetchLogs for doing several blocks at a time
 		logs, err := watcher.Fetcher.FetchLogs(watcher.Addresses, watcher.Topics, header)
 		if err != nil {
 			// TODO Handle fetch error in watcher
+			log.Error("Error while fetching logs in watcher")
 			return err
 		}
 

libraries/shared/watcher_test.go

@@ -41,10 +41,9 @@ func fakeTransformerInitializer(db *postgres.DB) shared2.Transformer {
 }
 
 var _ = Describe("Watcher", func() {
-	// TODO Add test for watcher setting the BC
+	It("initialises correctly", func() {
-	// TODO Add tests for log chunk delegation
+		// TODO Test watcher initialisation
-	// TODO Add tests for aggregate fetching
+	})
-	// TODO Add tests for MissingHeaders
 
 	It("adds transformers", func() {
 		watcher := shared.Watcher{}
@@ -102,5 +101,25 @@ var _ = Describe("Watcher", func() {
 			Expect(err).To(HaveOccurred())
 			Expect(fakeTransformer.executeWasCalled).To(BeFalse())
 		})
+
+		It("calls MissingHeaders", func() {
+			// TODO Tests for calling MissingHeaders
+		})
+
+		It("returns an error if missingHeaders returns an error", func() {
+			// TODO Test for propagating missingHeaders error
+		})
+
+		It("calls the log fetcher", func() {
+			// TODO Test for calling FetchLogs
+		})
+
+		It("returns an error if the log fetcher returns an error", func() {
+			// TODO Test for propagating log fetcher error
+		})
+
+		It("passes only relevant logs to each transformer", func() {
+			// TODO Test log delegation
+		})
 	})
 })