refstore: Add ref shortening

1 files changed, 68 insertions, 0 deletions

diff --git a/refstore/shorten_test.go b/refstore/shorten_test.go
new file mode 100644
index 00000000..1975ab3f
--- /dev/null
+++ b/refstore/shorten_test.go
@@ -0,0 +1,68 @@
+package refstore_test
+
+import (
+	"testing"
+
+	"codeberg.org/lindenii/furgit/refstore"
+)
+
+func TestShortenName(t *testing.T) {
+	t.Parallel()
+
+	t.Run("simple", func(t *testing.T) {
+		got := refstore.ShortenName("refs/heads/main", []string{"refs/heads/main"})
+		if got != "main" {
+			t.Fatalf("ShortenName simple = %q, want %q", got, "main")
+		}
+	})
+
+	t.Run("ambiguous with tags", func(t *testing.T) {
+		got := refstore.ShortenName(
+			"refs/heads/main",
+			[]string{
+				"refs/heads/main",
+				"refs/tags/main",
+			},
+		)
+		if got != "heads/main" {
+			t.Fatalf("ShortenName tags ambiguity = %q, want %q", got, "heads/main")
+		}
+	})
+
+	t.Run("strict remote head ambiguity", func(t *testing.T) {
+		// In strict mode, refs/remotes/%s/HEAD blocks shortening to "%s".
+		got := refstore.ShortenName(
+			"refs/heads/main",
+			[]string{
+				"refs/heads/main",
+				"refs/remotes/main/HEAD",
+			},
+		)
+		if got != "heads/main" {
+			t.Fatalf("ShortenName strict ambiguity = %q, want %q", got, "heads/main")
+		}
+	})
+
+	t.Run("deep fallback still shortens", func(t *testing.T) {
+		// refs/remotes/origin/main conflicts with refs/heads/origin/main for
+		// "origin/main", so it should fall back to "remotes/origin/main".
+		got := refstore.ShortenName(
+			"refs/remotes/origin/main",
+			[]string{
+				"refs/remotes/origin/main",
+				"refs/heads/origin/main",
+			},
+		)
+		if got != "remotes/origin/main" {
+			t.Fatalf("ShortenName deep fallback = %q, want %q", got, "remotes/origin/main")
+		}
+	})
+
+	t.Run("refs-prefix fallback", func(t *testing.T) {
+		name := "refs/notes/review/topic"
+		got := refstore.ShortenName(name, []string{name})
+		if got != "notes/review/topic" {
+			t.Fatalf("ShortenName refs-prefix fallback = %q, want %q", got, "notes/review/topic")
+		}
+	})
+}