Odb: use a callback instead of a channel for ForEach

A channel provides no way to specify whether we stopped sending data
because of an error or because there is no more data.

Therefore, make Odb.ForEach() take a callback with which the user is free to
do whatever they need, letting us return en error.

1 files changed, 35 insertions, 1 deletions

diff --git a/odb_test.go b/odb_test.go
index 17b3ad2..14a3658 100644
--- a/odb_test.go
+++ b/odb_test.go
@@ -3,6 +3,7 @@ package git
 import (
 	"io"
 	"os"
+	"errors"
 	"testing"
 )
 
@@ -48,7 +49,7 @@ parent 66e1c476199ebcd3e304659992233132c5a52c6c
 author John Doe <[email protected]> 1390682018 +0000
 committer John Doe <[email protected]> 1390682018 +0000
 
-Initial commit.`;
+Initial commit.`
 
 	oid, error := odb.Hash([]byte(str), ObjectCommit)
 	checkFatal(t, error)
@@ -60,3 +61,36 @@ Initial commit.`;
 		t.Fatal("Hash and write Oids are different")
 	}
 }
+
+func TestOdbForeach(t *testing.T) {
+	repo := createTestRepo(t)
+	defer os.RemoveAll(repo.Workdir())
+	_, _ = seedTestRepo(t, repo)
+
+	odb, err := repo.Odb()
+	checkFatal(t, err)
+
+	expect := 3
+	count := 0
+	err = odb.ForEach(func(id *Oid) error {
+		count++
+		return nil
+	})
+
+	checkFatal(t, err)
+	if count != expect {
+		t.Fatalf("Expected %v objects, got %v")
+	}
+
+	expect = 1
+	count = 0
+	to_return := errors.New("not really an error")
+	err = odb.ForEach(func(id *Oid) error {
+		count++
+		return to_return
+	})
+
+	if err != to_return {
+		t.Fatalf("Odb.ForEach() did not return the expected error, got %v", err)
+	}
+}