updated according to code review

all_test.go

@@ -364,7 +364,7 @@ func TestOptions_CopyRateLimit(t *testing.T) {
 
 func TestOptions_OnFileError(t *testing.T) {
 	opt := Options{
-		OnErr: nil,
+		OnError: nil,
 	}
 
 	// existing, process nromally
@@ -378,26 +378,23 @@ func TestOptions_OnFileError(t *testing.T) {
 	_, err = os.Stat("test/data.copy/case17/non-existing")
 	Expect(t, os.IsNotExist(err)).ToBe(true)
 
-	// existing, err not passed
-	var called bool
-	opt.OnErr = func(err error) error {
-		called = true
+	// existing, nil err not passed
+	opt.OnError = func(_, _ string, err error) error {
 		return err
 	}
 	err = Copy("test/data/case17", "test/data.copy/case17", opt)
 	Expect(t, err).ToBe(nil)
-	Expect(t, called).ToBe(false)
 
 	// not existing, process err
-	opt.OnErr = func(err error) error { return err }
+	opt.OnError = func(_, _ string, err error) error { return err }
 	err = Copy("test/data/case17/non-existing", "test/data.copy/case17/non-existing", opt)
 	Expect(t, os.IsNotExist(err)).ToBe(true)
 
 	_, err = os.Stat("test/data.copy/case17/non-existing")
 	Expect(t, os.IsNotExist(err)).ToBe(true)
 
 	// not existing, ignore err
-	opt.OnErr = func(err error) error { return nil }
+	opt.OnError = func(_, _ string, err error) error { return nil }
 	err = Copy("test/data/case17/non-existing", "test/data.copy/case17/non-existing", opt)
 	Expect(t, err).ToBe(nil)
 

copy.go

@@ -19,20 +19,16 @@ func Copy(src, dest string, opts ...Options) error {
 	opt := assureOptions(src, dest, opts...)
 	info, err := os.Lstat(src)
 	if err != nil {
-		return onError(err, opt)
+		return onError(src, dest, err, opt)
 	}
 	return switchboard(src, dest, info, opt)
 }
 
 // switchboard switches proper copy functions regarding file type, etc...
 // If there would be anything else here, add a case to this switchboard.
 func switchboard(src, dest string, info os.FileInfo, opt Options) (err error) {
-	defer func() {
-		err = onError(err, opt)
-	}()
-
 	if info.Mode()&os.ModeDevice != 0 && !opt.Specials {
-		return err
+		return onError(src, dest, err, opt)
 	}
 
 	switch {
@@ -46,7 +42,7 @@ func switchboard(src, dest string, info os.FileInfo, opt Options) (err error) {
 		err = fcopy(src, dest, info, opt)
 	}
 
-	return err
+	return onError(src, dest, err, opt)
 }
 
 // copyNextOrSkip decide if this src should be copied or not.
@@ -241,13 +237,10 @@ func fclose(f *os.File, reported *error) {
 
 // onError lets caller to handle errors
 // occured when copying a file.
-func onError(err error, opt Options) error {
-	if err == nil {
-		return nil
-	}
-	if opt.OnErr == nil {
+func onError(src, dest string, err error, opt Options) error {
+	if opt.OnError == nil {
 		return err
 	}
 
-	return opt.OnErr(err)
+	return opt.OnError(src, dest, err)
 }

options.go

@@ -15,7 +15,7 @@ type Options struct {
 	OnDirExists func(src, dest string) DirExistsAction
 
 	// OnErr lets called decide whether or not to continue on particular copy error.
-	OnErr func(err error) error
+	OnError func(src, dest string, err error) error
 
 	// Skip can specify which files should be skipped
 	Skip func(srcinfo os.FileInfo, src, dest string) (bool, error)
@@ -98,7 +98,7 @@ func getDefaultOptions(src, dest string) Options {
 			return Shallow // Do shallow copy
 		},
 		OnDirExists:       nil,                // Default behavior is "Merge".
-		OnErr:             nil,                // Default is "accept error"
+		OnError:           nil,                // Default is "accept error"
 		Skip:              nil,                // Do not skip anything
 		AddPermission:     0,                  // Add nothing
 		PermissionControl: PerservePermission, // Just preserve permission

test/data/case17/README.md

@@ -1,5 +1,5 @@
 So if you wanted to ignore error you should add something like this:
 ```go
-opt.OnFileErr = func(_ error) error { return nil } 
+opt.OnError = func(src, dst string, _ error) error { return nil } 
 ```
 The default value is nil and accepts raised error.