refactor(watch): return err instead of log fatal

core/change_event.go

@@ -7,4 +7,4 @@ type ChangeEvent struct {
 	FileName string
 }
 
-type ChangeCallback func(*ChangeEvent, *error)
+type ChangeCallback func(*ChangeEvent, *error) *error

infrastructure/file_watcher_test.go

@@ -17,9 +17,10 @@ func TestFileWatcher(t *testing.T) {
 		testFile := testFilePath + "/" + testFileName
 		ctx, cancel := context.WithCancel(context.Background())
 		var fileName string
-		callback := func(event *core.ChangeEvent, err *error) {
+		callback := func(event *core.ChangeEvent, err *error) *error {
 			fileName = event.FileName
 			cancel()
+			return nil
 		}
 		os.MkdirAll(testFilePath, 0755)
 		os.Create(testFilePath + "/" + testFileName)

use_case/watch.go

@@ -3,7 +3,6 @@ package use_case
 import (
 	"context"
 	"fmt"
-	"log"
 
 	"github.com/lucaschain/beholder/core"
 	"github.com/lucaschain/beholder/core/event_types"
@@ -20,19 +19,20 @@ type FileWatcher func(paths []string, callback core.ChangeCallback, ctx context.
 type CommandRunner func(command []string) error
 
 func onFileChange(c WatchConfig, commandRunner CommandRunner) core.ChangeCallback {
-	return func(event *core.ChangeEvent, err *error) {
+	return func(event *core.ChangeEvent, err *error) *error {
 		if err != nil {
-			log.Fatal(err)
+			return err
 		}
 
 		if event_types.Filter(event.Type, c.AllowedTypes) {
 			command := core.CommandTokens(c.Command, event)
 			commandError := commandRunner(command)
 
 			if commandError != nil && !c.AllowFailing {
-				log.Fatal(commandError)
+				return &commandError
 			}
 		}
+		return nil
 	}
 }
 

use_case/watch_test.go

@@ -2,6 +2,7 @@ package use_case_test
 
 import (
 	"context"
+	"errors"
 	"testing"
 
 	"github.com/lucaschain/beholder/core"
@@ -59,6 +60,48 @@ func TestWatch(t *testing.T) {
 
 		assert.Equal(t, []string{"echo", "CREATE", "test.txt"}, command)
 	})
+
+	t.Run("should return watcher errors without treating anything", func(t *testing.T) {
+		config := buildWatchConfig()
+		config.AllowedTypes = []event_types.EventType{event_types.Create}
+		config.Command = []string{"echo", "{type}", "{file}"}
+
+		var returnedError error
+		var fakeErr error
+		fakeWatcher := func(paths []string, callback core.ChangeCallback, ctx context.Context) {
+			fakeErr = errors.New("error")
+			returnedError = *callback(nil, &fakeErr)
+		}
+
+		use_case.Watch(config, fakeWatcher, func(command []string) error { return nil })
+
+		assert.Equal(t, fakeErr, returnedError)
+	})
+
+	t.Run("should return command errors if allowing errors", func(t *testing.T) {
+		config := buildWatchConfig()
+		config.AllowedTypes = []event_types.EventType{event_types.Create}
+		config.Command = []string{"echo", "{type}", "{file}"}
+		config.AllowFailing = true
+
+		var returnedError error
+		commandError := errors.New("error")
+		fakeRunner := func(command []string) error {
+			return commandError
+		}
+
+		fakeWatcher := buildFakeFileWatcher("test.txt", event_types.Create)
+		use_case.Watch(config, fakeWatcher, fakeRunner)
+
+		assert.Equal(t, commandError, returnedError)
+	})
+}
+
+func buildFakeErrorFileWatcher() use_case.FileWatcher {
+	return func(paths []string, callback core.ChangeCallback, ctx context.Context) {
+		error := errors.New("error")
+		callback(nil, &error)
+	}
 }
 
 func buildFakeFileWatcher(filename string, eventType event_types.EventType) use_case.FileWatcher {