Improve robutness of helper code

As per request, changed usage of pointer to int into plain int.
Use -1 value where nil use to be used.

k8sdeps/kunstruct/helper.go

@@ -31,7 +31,11 @@ import (
 // field of the first item in the foo list
 type PathSection struct {
 	fields []string
-	idx    *int
+	idx    int
+}
+
+func newPathSection() PathSection {
+	return PathSection{idx: -1}
 }
 
 func appendNonEmpty(section *PathSection, field string) {
@@ -41,7 +45,7 @@ func appendNonEmpty(section *PathSection, field string) {
 }
 
 func parseFields(path string) ([]PathSection, error) {
-	section := PathSection{}
+	section := newPathSection()
 	sectionset := []PathSection{}
 	if !strings.Contains(path, "[") {
 		section.fields = strings.Split(path, ".")
@@ -75,9 +79,9 @@ func parseFields(path string) ([]PathSection, error) {
 				if err != nil {
 					return nil, fmt.Errorf("invalid index %s", path)
 				}
-				section.idx = &tmpIdx
+				section.idx = tmpIdx
 				sectionset = append(sectionset, section)
-				section = PathSection{}
+				section = newPathSection()
 
 				start = i + 1
 				insideParentheses = false

k8sdeps/kunstruct/helper_test.go

@@ -23,20 +23,15 @@ import (
 
 type PathSectionSlice []PathSection
 
-func buildPath(idx *int, fields ...string) PathSectionSlice {
+func buildPath(idx int, fields ...string) PathSectionSlice {
 	return PathSectionSlice{PathSection{fields: fields, idx: idx}}
 }
 
-func (a PathSectionSlice) addSection(idx *int, fields ...string) PathSectionSlice {
+func (a PathSectionSlice) addSection(idx int, fields ...string) PathSectionSlice {
 	return append(a, PathSection{fields: fields, idx: idx})
 }
 
 func TestParseField(t *testing.T) {
-	i := 1
-	var one *int = &i
-	j := 0
-	var zero *int = &j
-
 	tests := []struct {
 		name          string
 		pathToField   string
@@ -47,55 +42,55 @@ func TestParseField(t *testing.T) {
 		{
 			name:          "oneField",
 			pathToField:   "Kind",
-			expectedValue: buildPath(nil, "Kind"),
+			expectedValue: buildPath(-1, "Kind"),
 			errorExpected: false,
 		},
 		{
 			name:          "twoFields",
 			pathToField:   "metadata.name",
-			expectedValue: buildPath(nil, "metadata", "name"),
+			expectedValue: buildPath(-1, "metadata", "name"),
 			errorExpected: false,
 		},
 		{
 			name:          "threeFields",
 			pathToField:   "spec.ports.port",
-			expectedValue: buildPath(nil, "spec", "ports", "port"),
+			expectedValue: buildPath(-1, "spec", "ports", "port"),
 			errorExpected: false,
 		},
 		{
 			name:          "empty",
 			pathToField:   "",
-			expectedValue: buildPath(nil, ""),
+			expectedValue: buildPath(-1, ""),
 			errorExpected: false,
 		},
 		{
 			name:          "validStringIndex",
 			pathToField:   "that[1]",
-			expectedValue: buildPath(one, "that"),
+			expectedValue: buildPath(1, "that"),
 			errorExpected: false,
 		},
 		{
 			name:          "sliceInSlice",
 			pathToField:   "that[1][0]",
-			expectedValue: buildPath(one, "that").addSection(zero),
+			expectedValue: buildPath(1, "that").addSection(0),
 			errorExpected: false,
 		},
 		{
 			name:          "validStructSubField",
 			pathToField:   "those[1].field2",
-			expectedValue: buildPath(one, "those").addSection(nil, "field2"),
+			expectedValue: buildPath(1, "those").addSection(-1, "field2"),
 			errorExpected: false,
 		},
 		{
 			name:          "validStructSubFieldIndex",
 			pathToField:   "these[1].field2[0]",
-			expectedValue: buildPath(one, "these").addSection(zero, "field2"),
+			expectedValue: buildPath(1, "these").addSection(0, "field2"),
 			errorExpected: false,
 		},
 		{
 			name:          "validStructSubFieldIndexSubfield",
 			pathToField:   "complextree[1].field2[1].stringsubfield",
-			expectedValue: buildPath(one, "complextree").addSection(one, "field2").addSection(nil, "stringsubfield"),
+			expectedValue: buildPath(1, "complextree").addSection(1, "field2").addSection(-1, "stringsubfield"),
 			errorExpected: false,
 		},
 		{
@@ -119,7 +114,7 @@ func TestParseField(t *testing.T) {
 		{
 			name:          "validFieldsWithQuotes",
 			pathToField:   "'complextree'[1].field2[1].'stringsubfield'",
-			expectedValue: buildPath(one, "complextree").addSection(one, "field2").addSection(nil, "stringsubfield"),
+			expectedValue: buildPath(1, "complextree").addSection(1, "field2").addSection(-1, "stringsubfield"),
 			errorExpected: false,
 		},
 	}

k8sdeps/kunstruct/kunstruct.go

@@ -92,7 +92,7 @@ func (fs *UnstructAdapter) selectSubtree(path string) (map[string]interface{}, [
 		idx := sections[sectionIdx].idx
 		fields := sections[sectionIdx].fields
 
-		if idx == nil {
+		if idx == -1 {
 			// This section has no index
 			return content, fields, true, nil
 		}
@@ -107,24 +107,24 @@ func (fs *UnstructAdapter) selectSubtree(path string) (map[string]interface{}, [
 		if !ok {
 			return content, fields, false, fmt.Errorf("%v is of the type %T, expected []interface{}", indexedField, indexedField)
 		}
-		if *idx >= len(s) {
-			return content, fields, false, fmt.Errorf("index %d is out of bounds", *idx)
+		if idx >= len(s) {
+			return content, fields, false, fmt.Errorf("index %d is out of bounds", idx)
 		}
 
 		if sectionIdx == lastSectionIdx-1 {
 			// This is the last section. Let's build a fake map
 			// to let the rest of the field extraction to work.
-			idxstring := fmt.Sprintf("[%v]", *idx)
-			newContent := map[string]interface{}{idxstring: s[*idx]}
+			idxstring := fmt.Sprintf("[%v]", idx)
+			newContent := map[string]interface{}{idxstring: s[idx]}
 			newFields := []string{idxstring}
 			return newContent, newFields, true, nil
 		}
 
-		newContent, ok := s[*idx].(map[string]interface{})
+		newContent, ok := s[idx].(map[string]interface{})
 		if !ok {
 			// Only map are supported here
 			return content, fields, false,
-				fmt.Errorf("%#v is expected to be of type map[string]interface{}", s[*idx])
+				fmt.Errorf("%#v is expected to be of type map[string]interface{}", s[idx])
 		}
 		content = newContent
 	}