Return early when linting if the `templates/` dir does not exist

The `vaildateTemplatesDir` function would still return `nil` if the directory doesn't exist,
so the early return that was documented never occurs.

Signed-off-by: Zach Burgess <zachburg@google.com>

pkg/cmd/testdata/output/lint-chart-with-bad-subcharts-with-subcharts.txt

@@ -1,6 +1,5 @@
 ==> Linting testdata/testcharts/chart-with-bad-subcharts
 [INFO] Chart.yaml: icon is recommended
-[ERROR] templates/: error unpacking subchart bad-subchart in chart-with-bad-subcharts: validation: chart.metadata.name is required
 [ERROR] : unable to load chart
 	error unpacking subchart bad-subchart in chart-with-bad-subcharts: validation: chart.metadata.name is required
 
@@ -9,7 +8,6 @@
 [ERROR] Chart.yaml: apiVersion is required. The value must be either "v1" or "v2"
 [ERROR] Chart.yaml: version is required
 [INFO] Chart.yaml: icon is recommended
-[ERROR] templates/: validation: chart.metadata.name is required
 [ERROR] : unable to load chart
 	validation: chart.metadata.name is required
 

pkg/cmd/testdata/output/lint-chart-with-bad-subcharts.txt

@@ -1,6 +1,5 @@
 ==> Linting testdata/testcharts/chart-with-bad-subcharts
 [INFO] Chart.yaml: icon is recommended
-[ERROR] templates/: error unpacking subchart bad-subchart in chart-with-bad-subcharts: validation: chart.metadata.name is required
 [ERROR] : unable to load chart
 	error unpacking subchart bad-subchart in chart-with-bad-subcharts: validation: chart.metadata.name is required
 

pkg/cmd/testdata/output/lint-quiet-with-error.txt

@@ -1,7 +1,6 @@
 ==> Linting testdata/testcharts/chart-bad-requirements
 [ERROR] Chart.yaml: unable to parse YAML
 	error converting YAML to JSON: yaml: line 6: did not find expected '-' indicator
-[ERROR] templates/: cannot load Chart.yaml: error converting YAML to JSON: yaml: line 6: did not find expected '-' indicator
 [ERROR] : unable to load chart
 	cannot load Chart.yaml: error converting YAML to JSON: yaml: line 6: did not find expected '-' indicator
 

pkg/lint/lint_test.go

@@ -39,7 +39,7 @@ const invalidChartFileDir = "rules/testdata/invalidchartfile"
 
 func TestBadChart(t *testing.T) {
 	m := RunAll(badChartDir, values, namespace).Messages
-	if len(m) != 8 {
+	if len(m) != 7 {
 		t.Errorf("Number of errors %v", len(m))
 		t.Errorf("All didn't fail with expected errors, got %#v", m)
 	}

pkg/lint/rules/template.go

@@ -54,13 +54,13 @@ func TemplatesWithSkipSchemaValidation(linter *support.Linter, values map[string
 	fpath := "templates/"
 	templatesPath := filepath.Join(linter.ChartDir, fpath)
 
-	templatesDirExist := linter.RunLinterRule(support.WarningSev, fpath, validateTemplatesDir(templatesPath))
-
 	// Templates directory is optional for now
-	if !templatesDirExist {
+	if _, err := os.Stat(templatesPath); errors.Is(err, os.ErrNotExist) {
 		return
 	}
 
+	linter.RunLinterRule(support.WarningSev, fpath, validateTemplatesDir(templatesPath))
+
 	// Load chart and parse templates
 	chart, err := loader.Load(linter.ChartDir)
 
@@ -195,10 +195,12 @@ func validateTopIndentLevel(content string) error {
 
 // Validation functions
 func validateTemplatesDir(templatesPath string) error {
-	if fi, err := os.Stat(templatesPath); err == nil {
-		if !fi.IsDir() {
-			return errors.New("not a directory")
-		}
+	fi, err := os.Stat(templatesPath)
+	if err != nil {
+		return err
+	}
+	if !fi.IsDir() {
+		return errors.New("not a directory")
 	}
 	return nil
 }