git: Add GitattributesSupportReadingFromHead flagej-5720-add-flag-GitatrributesSupportsReadingFromHead

Git 2.43.0 starts supporting reading gitattributes from HEAD reference.
This is a required feature for us to get rid of gitattributes-related
RPCs. This `GitattributesSupportReadingFromHead` flag function check
if current git version is above or equal 2.43.0.

2 files changed, 34 insertions, 0 deletions

diff --git a/internal/git/version.go b/internal/git/version.go
index 4a552b62c..e0d81043a 100644
--- a/internal/git/version.go
+++ b/internal/git/version.go
@@ -109,6 +109,14 @@ func (v Version) LessThan(other Version) bool {
 	}
 }
 
+// GitattributesSupportReadingFromHead detects whether the Git version supports reading
+// gitattributes from HEAD reference in bare repositories automatically.
+func (v Version) GitattributesSupportReadingFromHead() bool {
+	return !v.LessThan(Version{
+		major: 2, minor: 43,
+	})
+}
+
 func parseVersion(versionStr string) (Version, error) {
 	versionSplit := strings.SplitN(versionStr, ".", 4)
 	if len(versionSplit) < 3 {
diff --git a/internal/git/version_test.go b/internal/git/version_test.go
index c9a0db8fb..e7374da77 100644
--- a/internal/git/version_test.go
+++ b/internal/git/version_test.go
@@ -122,3 +122,29 @@ func TestVersion_IsSupported(t *testing.T) {
 		})
 	}
 }
+
+func TestVersion_GitattributesSupportReadingFromHead(t *testing.T) {
+	t.Parallel()
+
+	for _, tc := range []struct {
+		version string
+		expect  bool
+	}{
+		{"1.0.0", false},
+		{"2.40.2", false},
+		{"2.41.0", false},
+		{"2.42.0", false},
+		{"2.42.2", false},
+		{"2.43.0", true},
+		{"2.43.1.gl2", true},
+		{"3.0.0", true},
+	} {
+		tc := tc
+		t.Run(tc.version, func(t *testing.T) {
+			version, err := parseVersion(tc.version)
+			require.NoError(t, err)
+			require.Equal(t, tc.expect,
+				version.GitattributesSupportReadingFromHead())
+		})
+	}
+}