refstore/reftable: Add basic implementation

1 files changed, 172 insertions, 0 deletions

diff --git a/refstore/reftable/reftable_test.go b/refstore/reftable/reftable_test.go
new file mode 100644
index 00000000..28201af2
--- /dev/null
+++ b/refstore/reftable/reftable_test.go
@@ -0,0 +1,172 @@
+package reftable_test
+
+import (
+	"errors"
+	"os"
+	"path/filepath"
+	"slices"
+	"testing"
+
+	"codeberg.org/lindenii/furgit/internal/testgit"
+	"codeberg.org/lindenii/furgit/objectid"
+	"codeberg.org/lindenii/furgit/ref"
+	"codeberg.org/lindenii/furgit/refstore"
+	"codeberg.org/lindenii/furgit/refstore/reftable"
+)
+
+// newBareReftableRepo creates a bare repository that uses reftable ref storage.
+func newBareReftableRepo(tb testing.TB, algo objectid.Algorithm) *testgit.TestRepo {
+	tb.Helper()
+	return testgit.NewRepo(tb, algo, testgit.RepoOptions{Bare: true, RefFormat: "reftable"})
+}
+
+// openStore opens a reftable store against repoDir/reftable.
+func openStore(tb testing.TB, repoDir string, algo objectid.Algorithm) *reftable.Store {
+	tb.Helper()
+	root, err := os.OpenRoot(filepath.Join(repoDir, "reftable"))
+	if err != nil {
+		tb.Fatalf("OpenRoot(reftable): %v", err)
+	}
+	tb.Cleanup(func() { _ = root.Close() })
+	store, err := reftable.New(root, algo)
+	if err != nil {
+		tb.Fatalf("reftable.New: %v", err)
+	}
+	return store
+}
+
+func TestResolveAndResolveFully(t *testing.T) {
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		repo := newBareReftableRepo(t, algo)
+		_, _, id := repo.MakeCommit(t, "resolve")
+		repo.UpdateRef(t, "refs/heads/main", id)
+		repo.SymbolicRef(t, "HEAD", "refs/heads/main")
+
+		store := openStore(t, repo.Dir(), algo)
+		head, err := store.Resolve("HEAD")
+		if err != nil {
+			t.Fatalf("Resolve(HEAD): %v", err)
+		}
+		sym, ok := head.(ref.Symbolic)
+		if !ok {
+			t.Fatalf("Resolve(HEAD) type = %T, want ref.Symbolic", head)
+		}
+		if sym.Target != "refs/heads/main" {
+			t.Fatalf("Resolve(HEAD) target = %q, want refs/heads/main", sym.Target)
+		}
+
+		main, err := store.ResolveFully("HEAD")
+		if err != nil {
+			t.Fatalf("ResolveFully(HEAD): %v", err)
+		}
+		if main.ID != id {
+			t.Fatalf("ResolveFully(HEAD) id = %s, want %s", main.ID, id)
+		}
+
+		if _, err := store.Resolve("refs/heads/missing"); !errors.Is(err, refstore.ErrReferenceNotFound) {
+			t.Fatalf("Resolve(missing) error = %v", err)
+		}
+	})
+}
+
+func TestResolveFullyCycle(t *testing.T) {
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		repo := newBareReftableRepo(t, algo)
+		repo.SymbolicRef(t, "refs/heads/a", "refs/heads/b")
+		repo.SymbolicRef(t, "refs/heads/b", "refs/heads/a")
+
+		store := openStore(t, repo.Dir(), algo)
+		if _, err := store.ResolveFully("refs/heads/a"); err == nil {
+			t.Fatalf("ResolveFully(cycle) expected error")
+		}
+	})
+}
+
+func TestListAndShorten(t *testing.T) {
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		repo := newBareReftableRepo(t, algo)
+		_, _, id := repo.MakeCommit(t, "list")
+		repo.UpdateRef(t, "refs/heads/main", id)
+		repo.UpdateRef(t, "refs/heads/feature", id)
+		repo.UpdateRef(t, "refs/tags/main", id)
+		repo.UpdateRef(t, "refs/remotes/origin/main", id)
+
+		store := openStore(t, repo.Dir(), algo)
+		all, err := store.List("")
+		if err != nil {
+			t.Fatalf("List(all): %v", err)
+		}
+		names := make([]string, 0, len(all))
+		for _, entry := range all {
+			names = append(names, entry.Name())
+		}
+		want := []string{"HEAD", "refs/heads/feature", "refs/heads/main", "refs/remotes/origin/main", "refs/tags/main"}
+		if !slices.Equal(names, want) {
+			t.Fatalf("List(all) = %v, want %v", names, want)
+		}
+
+		heads, err := store.List("refs/heads/*")
+		if err != nil {
+			t.Fatalf("List(heads): %v", err)
+		}
+		headNames := make([]string, 0, len(heads))
+		for _, entry := range heads {
+			headNames = append(headNames, entry.Name())
+		}
+		wantHeads := []string{"refs/heads/feature", "refs/heads/main"}
+		if !slices.Equal(headNames, wantHeads) {
+			t.Fatalf("List(heads) = %v, want %v", headNames, wantHeads)
+		}
+
+		short, err := store.Shorten("refs/remotes/origin/main")
+		if err != nil {
+			t.Fatalf("Shorten(remote): %v", err)
+		}
+		if short != "origin/main" {
+			t.Fatalf("Shorten(remote) = %q, want origin/main", short)
+		}
+	})
+}
+
+func TestTombstoneNewestWins(t *testing.T) {
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		repo := newBareReftableRepo(t, algo)
+		_, _, oldID := repo.MakeCommit(t, "old")
+		repo.UpdateRef(t, "refs/heads/main", oldID)
+		_, _, newID := repo.MakeCommit(t, "new")
+		repo.UpdateRef(t, "refs/heads/main", newID)
+		repo.DeleteRef(t, "refs/heads/main")
+
+		store := openStore(t, repo.Dir(), algo)
+		if _, err := store.Resolve("refs/heads/main"); !errors.Is(err, refstore.ErrReferenceNotFound) {
+			t.Fatalf("Resolve(main) after delete error = %v", err)
+		}
+	})
+}
+
+func TestAnnotatedTagPeeled(t *testing.T) {
+	testgit.ForEachAlgorithm(t, func(t *testing.T, algo objectid.Algorithm) {
+		repo := newBareReftableRepo(t, algo)
+		_, _, commitID := repo.MakeCommit(t, "tagged")
+		tagID := repo.TagAnnotated(t, "v1.0.0", commitID, "annotated")
+
+		store := openStore(t, repo.Dir(), algo)
+		resolved, err := store.Resolve("refs/tags/v1.0.0")
+		if err != nil {
+			t.Fatalf("Resolve(tag): %v", err)
+		}
+		detached, ok := resolved.(ref.Detached)
+		if !ok {
+			t.Fatalf("Resolve(tag) type = %T, want ref.Detached", resolved)
+		}
+		if detached.ID != tagID {
+			t.Fatalf("Resolve(tag) id = %s, want %s", detached.ID, tagID)
+		}
+		if detached.Peeled == nil {
+			t.Fatalf("Resolve(tag) peeled = nil")
+		}
+		if *detached.Peeled != commitID {
+			t.Fatalf("Resolve(tag) peeled = %s, want %s", *detached.Peeled, commitID)
+		}
+	})
+}