improve test and comment

Author: wxiaoguang

modules/git/attribute/batch_test.go

@@ -102,13 +102,17 @@ func Test_nulSeparatedAttributeWriter_ReadAttribute(t *testing.T) {
 	}, attr)
 }
 
-var expectedAttrs = Attributes{
-	LinguistGenerated:     "unspecified",
-	LinguistDetectable:    "unspecified",
-	LinguistDocumentation: "unspecified",
-	LinguistVendored:      "unspecified",
-	LinguistLanguage:      "Python",
-	GitlabLanguage:        "unspecified",
+func expectedAttrs() *Attributes {
+	return &Attributes{
+		m: map[string]Attribute{
+			LinguistGenerated:     "unspecified",
+			LinguistDetectable:    "unspecified",
+			LinguistDocumentation: "unspecified",
+			LinguistVendored:      "unspecified",
+			LinguistLanguage:      "Python",
+			GitlabLanguage:        "unspecified",
+		},
+	}
 }
 
 func Test_BatchChecker(t *testing.T) {
@@ -127,7 +131,7 @@ func Test_BatchChecker(t *testing.T) {
 		defer checker.Close()
 		attributes, err := checker.CheckPath("i-am-a-python.p")
 		assert.NoError(t, err)
-		assert.Equal(t, expectedAttrs, attributes)
+		assert.Equal(t, expectedAttrs(), attributes)
 	})
 
 	// run git check-attr on work tree
@@ -148,7 +152,7 @@ func Test_BatchChecker(t *testing.T) {
 		defer checker.Close()
 		attributes, err := checker.CheckPath("i-am-a-python.p")
 		assert.NoError(t, err)
-		assert.Equal(t, expectedAttrs, attributes)
+		assert.Equal(t, expectedAttrs(), attributes)
 	})
 
 	if !git.DefaultFeatures().SupportCheckAttrOnBare {
@@ -163,6 +167,6 @@ func Test_BatchChecker(t *testing.T) {
 
 		attributes, err := checker.CheckPath("i-am-a-python.p")
 		assert.NoError(t, err)
-		assert.Equal(t, expectedAttrs, attributes)
+		assert.Equal(t, expectedAttrs(), attributes)
 	})
 }

modules/git/attribute/checker.go

@@ -21,7 +21,7 @@ func checkAttrCommand(gitRepo *git.Repository, treeish string, filenames, attrib
 		cmd.AddArguments("--all")
 	}
 
-	// there is treeish, read from source or index
+	// there is treeish, read from bare repo or temp index created by "read-tree"
 	if treeish != "" {
 		if git.DefaultFeatures().SupportCheckAttrOnBare {
 			cmd.AddArguments("--source")
@@ -39,7 +39,7 @@ func checkAttrCommand(gitRepo *git.Repository, treeish string, filenames, attrib
 			)
 			cancel = deleteTemporaryFile
 		}
-	} // no treeish, read from working directory
+	} // else: no treeish, assume it is a not a bare repo, read from working directory
 
 	cmd.AddDynamicArguments(attributes...)
 	if len(filenames) > 0 {

modules/git/attribute/checker_test.go

@@ -32,7 +32,7 @@ func Test_Checker(t *testing.T) {
 		})
 		assert.NoError(t, err)
 		assert.Len(t, attrs, 1)
-		assert.Equal(t, expectedAttrs, attrs["i-am-a-python.p"])
+		assert.Equal(t, expectedAttrs(), attrs["i-am-a-python.p"])
 	})
 
 	// run git check-attr on work tree
@@ -54,7 +54,7 @@ func Test_Checker(t *testing.T) {
 		})
 		assert.NoError(t, err)
 		assert.Len(t, attrs, 1)
-		assert.Equal(t, expectedAttrs, attrs["i-am-a-python.p"])
+		assert.Equal(t, expectedAttrs(), attrs["i-am-a-python.p"])
 	})
 
 	if !git.DefaultFeatures().SupportCheckAttrOnBare {
@@ -69,6 +69,6 @@ func Test_Checker(t *testing.T) {
 		})
 		assert.NoError(t, err)
 		assert.Len(t, attrs, 1)
-		assert.Equal(t, expectedAttrs, attrs["i-am-a-python.p"])
+		assert.Equal(t, expectedAttrs(), attrs["i-am-a-python.p"])
 	})
 }