Merge pull request #3985 from monopole/stringslice

Gather some string slice utils.

api/filters/imagetag/legacy.go

@@ -4,6 +4,7 @@
 package imagetag
 
 import (
+	"sigs.k8s.io/kustomize/api/internal/utils"
 	"sigs.k8s.io/kustomize/api/types"
 	"sigs.k8s.io/kustomize/kyaml/kio"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
@@ -74,7 +75,7 @@ func (f findFieldsFilter) walk(node *yaml.RNode) error {
 				return err
 			}
 			key := n.Key.YNode().Value
-			if contains(f.fields, key) {
+			if utils.StringSliceContains(f.fields, key) {
 				return f.fieldCallback(n.Value)
 			}
 			return nil
@@ -87,15 +88,6 @@ func (f findFieldsFilter) walk(node *yaml.RNode) error {
 	return nil
 }
 
-func contains(slice []string, str string) bool {
-	for _, s := range slice {
-		if s == str {
-			return true
-		}
-	}
-	return false
-}
-
 func checkImageTagsFn(imageTag types.Image) fieldCallback {
 	return func(node *yaml.RNode) error {
 		if node.YNode().Kind != yaml.SequenceNode {

api/internal/utils/stringslice.go

@@ -0,0 +1,44 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package utils
+
+// StringSliceIndex returns the index of the str, else -1.
+func StringSliceIndex(slice []string, str string) int {
+	for i := range slice {
+		if slice[i] == str {
+			return i
+		}
+	}
+	return -1
+}
+
+// StringSliceContains returns true if the slice has the string.
+func StringSliceContains(slice []string, str string) bool {
+	for _, s := range slice {
+		if s == str {
+			return true
+		}
+	}
+	return false
+}
+
+// SameEndingSubSlice returns true if the slices end the same way, e.g.
+// {"a", "b", "c"}, {"b", "c"} => true
+// {"a", "b", "c"}, {"a", "b"} => false
+// If one slice is empty and the other is not, return false.
+func SameEndingSubSlice(shortest, longest []string) bool {
+	if len(shortest) > len(longest) {
+		longest, shortest = shortest, longest
+	}
+	diff := len(longest) - len(shortest)
+	if len(shortest) == 0 {
+		return diff == 0
+	}
+	for i := len(shortest) - 1; i >= 0; i-- {
+		if longest[i+diff] != shortest[i] {
+			return false
+		}
+	}
+	return true
+}

api/internal/utils/stringslice_test.go

@@ -0,0 +1,37 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package utils_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	. "sigs.k8s.io/kustomize/api/internal/utils"
+)
+
+func TestStringSliceIndex(t *testing.T) {
+	assert.Equal(t, 0, StringSliceIndex([]string{"a", "b"}, "a"))
+	assert.Equal(t, 1, StringSliceIndex([]string{"a", "b"}, "b"))
+	assert.Equal(t, -1, StringSliceIndex([]string{"a", "b"}, "c"))
+	assert.Equal(t, -1, StringSliceIndex([]string{}, "c"))
+}
+
+func TestStringSliceContains(t *testing.T) {
+	assert.True(t, StringSliceContains([]string{"a", "b"}, "a"))
+	assert.True(t, StringSliceContains([]string{"a", "b"}, "b"))
+	assert.False(t, StringSliceContains([]string{"a", "b"}, "c"))
+	assert.False(t, StringSliceContains([]string{}, "c"))
+}
+
+func TestSameEndingSubarray(t *testing.T) {
+	assert.True(t, SameEndingSubSlice([]string{"", "a", "b"}, []string{"a", "b"}))
+	assert.True(t, SameEndingSubSlice([]string{"a", "b", ""}, []string{"b", ""}))
+	assert.True(t, SameEndingSubSlice([]string{"a", "b"}, []string{"a", "b"}))
+	assert.True(t, SameEndingSubSlice([]string{"a", "b"}, []string{"b"}))
+	assert.True(t, SameEndingSubSlice([]string{"b"}, []string{"a", "b"}))
+	assert.True(t, SameEndingSubSlice([]string{}, []string{}))
+	assert.False(t, SameEndingSubSlice([]string{"a", "b"}, []string{"b", "a"}))
+	assert.False(t, SameEndingSubSlice([]string{"a", "b"}, []string{}))
+	assert.False(t, SameEndingSubSlice([]string{"a", "b"}, []string{""}))
+}

api/resource/resource.go

@@ -199,22 +199,6 @@ func (r *Resource) appendCsvAnnotation(name, value string) {
 	}
 }
 
-func SameEndingSubarray(shortest, longest []string) bool {
-	if len(shortest) > len(longest) {
-		longest, shortest = shortest, longest
-	}
-	diff := len(longest) - len(shortest)
-	if len(shortest) == 0 {
-		return diff == 0
-	}
-	for i := len(shortest) - 1; i >= 0; i-- {
-		if longest[i+diff] != shortest[i] {
-			return false
-		}
-	}
-	return true
-}
-
 // Implements ResCtx GetNamePrefixes
 func (r *Resource) GetNamePrefixes() []string {
 	return r.getCsvAnnotation(utils.BuildAnnotationPrefixes)
@@ -237,7 +221,8 @@ func (r *Resource) getCsvAnnotation(name string) []string {
 // as OutermostPrefixSuffix but performs a deeper comparison
 // of the suffix and prefix slices.
 func (r *Resource) PrefixesSuffixesEquals(o ResCtx) bool {
-	return SameEndingSubarray(r.GetNamePrefixes(), o.GetNamePrefixes()) && SameEndingSubarray(r.GetNameSuffixes(), o.GetNameSuffixes())
+	return utils.SameEndingSubSlice(r.GetNamePrefixes(), o.GetNamePrefixes()) &&
+		utils.SameEndingSubSlice(r.GetNameSuffixes(), o.GetNameSuffixes())
 }
 
 // RemoveBuildAnnotations removes annotations created by the build process.

api/resource/resource_test.go

@@ -9,6 +9,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"sigs.k8s.io/kustomize/api/internal/utils"
 	"sigs.k8s.io/kustomize/api/provider"
 	. "sigs.k8s.io/kustomize/api/resource"
 	"sigs.k8s.io/kustomize/api/types"
@@ -1077,7 +1078,7 @@ func TestSameEndingSubarray(t *testing.T) {
 	for n := range testCases {
 		tc := testCases[n]
 		t.Run(n, func(t *testing.T) {
-			assert.Equal(t, tc.expected, SameEndingSubarray(tc.a, tc.b))
+			assert.Equal(t, tc.expected, utils.SameEndingSubSlice(tc.a, tc.b))
 		})
 	}
 }