chore: simplify matcher flag functions

cmd/command.go

@@ -26,7 +26,7 @@ import (
 )
 
 // Command returns a complete command line handler for krf.
-func Command() *cobra.Command { //nolint:funlen,maintidx
+func Command() *cobra.Command { //nolint:funlen
 	cmd := &cobra.Command{
 		Use:     "krf [directory|file|-]",
 		Long:    "krf - kubernetes resource filter",
@@ -50,195 +50,163 @@ func Command() *cobra.Command { //nolint:funlen,maintidx
 	mf := mflag.NewMatcherFlags(cmd.Flags())
 
 	// Define --annotation flag.
-	mf.StringSliceErrorMatcher(matcher.NewAnnotationMatcher,
+	mf.StringSliceMatcher(matcher.NewAnnotationMatcher,
 		"annotation",
-		nil,
 		"include resources by annotation")
 
 	// Define --not-annotation flag.
-	mf.StringSliceErrorMatcher(matcher.NewAnnotationMatcher,
+	mf.StringSliceMatcher(matcher.NewAnnotationMatcher,
 		"not-annotation",
-		nil,
 		"exclude resources by annotation")
 
 	// Define --apiversion flag.
-	mf.StringSliceErrorMatcher(matcher.NewAPIVersionMatcher,
+	mf.StringSliceMatcher(matcher.NewAPIVersionMatcher,
 		"apiversion",
-		nil,
 		"include resources by api version")
 
 	// Define --not-apiversion flag.
-	mf.StringSliceErrorMatcher(matcher.NewAPIVersionMatcher,
+	mf.StringSliceMatcher(matcher.NewAPIVersionMatcher,
 		"not-apiversion",
-		nil,
 		"exclude resources by api version")
 
 	// Define --cluster-scoped flag.
 	mf.BoolMatcher(matcher.NewClusterScopedMatcher,
 		"cluster-scoped",
-		false,
 		"include resources that are cluster-scoped")
 
 	// Define --contains flag.
 	mf.StringSliceMatcher(matcher.NewContainsMatcher,
 		"contains",
-		nil,
 		"include resources by substring contents")
 
 	// Define --not-contains flag.
 	mf.StringSliceMatcher(matcher.NewContainsMatcher,
 		"not-contains",
-		nil,
 		"exclude resources by substring contents")
 
 	// Define --diff flag.
-	mf.StringErrorMatcher(matcher.NewDiffMatcher,
+	mf.StringMatcher(matcher.NewDiffMatcher,
 		"diff",
-		"",
 		"include resources which differ from those in a file")
 
 	// Define --not-diff flag.
-	mf.StringErrorMatcher(matcher.NewDiffMatcher,
+	mf.StringMatcher(matcher.NewDiffMatcher,
 		"not-diff",
-		"",
 		"exclude resources which differ from those in a file")
 
 	// Define --exec flag.
-	mf.StringErrorMatcher(matcher.NewExecMatcher,
+	mf.StringMatcher(matcher.NewExecMatcher,
 		"exec",
-		"",
 		"include resources by executing a script")
 
 	// Define --not-exec flag.
-	mf.StringErrorMatcher(matcher.NewExecMatcher,
+	mf.StringMatcher(matcher.NewExecMatcher,
 		"not-exec",
-		"",
 		"exclude resources by executing a script")
 
 	// Define --fieldpath flag.
-	mf.StringSliceErrorMatcher(matcher.NewFieldPathMatcher,
+	mf.StringSliceMatcher(matcher.NewFieldPathMatcher,
 		"fieldpath",
-		nil,
 		"include resources by kustomize fieldpath")
 
 	// Define --not-fieldpath flag.
-	mf.StringSliceErrorMatcher(matcher.NewFieldPathMatcher,
+	mf.StringSliceMatcher(matcher.NewFieldPathMatcher,
 		"not-fieldpath",
-		nil,
 		"exclude resources by kustomize fieldpath")
 
 	// Define --jsonpath flag.
-	mf.StringSliceErrorMatcher(matcher.NewJsonpathMatcher,
+	mf.StringSliceMatcher(matcher.NewJsonpathMatcher,
 		"jsonpath",
-		nil,
 		"include resources by jsonpath")
 
 	// Define --not-jsonpath flag.
-	mf.StringSliceErrorMatcher(matcher.NewJsonpathMatcher,
+	mf.StringSliceMatcher(matcher.NewJsonpathMatcher,
 		"not-jsonpath",
-		nil,
 		"exclude resources by jsonpath")
 
 	// Define --kind flag.
-	mf.StringSliceErrorMatcher(matcher.NewKindMatcher,
+	mf.StringSliceMatcher(matcher.NewKindMatcher,
 		"kind",
-		nil,
 		"include resources by kind")
 
 	// Define --not-kind flag.
-	mf.StringSliceErrorMatcher(matcher.NewKindMatcher,
+	mf.StringSliceMatcher(matcher.NewKindMatcher,
 		"not-kind",
-		nil,
 		"exclude resources by kind")
 
 	// Define --label flag.
-	mf.StringSliceErrorMatcher(matcher.NewLabelMatcher,
+	mf.StringSliceMatcher(matcher.NewLabelMatcher,
 		"label",
-		nil,
 		"include resources by label")
 
 	// Define --not-label flag.
-	mf.StringSliceErrorMatcher(matcher.NewLabelMatcher,
+	mf.StringSliceMatcher(matcher.NewLabelMatcher,
 		"not-label",
-		nil,
 		"exclude resources by label")
 
 	// Define --name flag.
-	mf.StringSliceErrorMatcher(matcher.NewNameMatcher,
+	mf.StringSliceMatcher(matcher.NewNameMatcher,
 		"name",
-		nil,
 		"include resources by name")
 
 	// Define --not-name flag.
-	mf.StringSliceErrorMatcher(matcher.NewNameMatcher,
+	mf.StringSliceMatcher(matcher.NewNameMatcher,
 		"not-name",
-		nil,
 		"exclude resources by name")
 
 	// Define --namespace flag.
-	mf.StringSliceErrorMatcher(matcher.NewNamespaceMatcher,
+	mf.StringSliceMatcher(matcher.NewNamespaceMatcher,
 		"namespace",
-		nil,
 		"include resources by namespace")
 
 	// Define --not-namespace flag.
-	mf.StringSliceErrorMatcher(matcher.NewNamespaceMatcher,
+	mf.StringSliceMatcher(matcher.NewNamespaceMatcher,
 		"not-namespace",
-		nil,
 		"exclude resources by namespace")
 
 	// Define --namespace-scoped flag.
 	mf.BoolMatcher(matcher.NewNamespaceScopedMatcher,
 		"namespace-scoped",
-		false,
 		"include resources that are namespace-scoped")
 
 	// Define --patch flag.
 	mf.BoolMatcher(matcher.NewPatchMatcher,
 		"patch",
-		false,
 		"include resources from patch files")
 
 	// Define --not-patch flag.
 	mf.BoolMatcher(matcher.NewPatchMatcher,
 		"not-patch",
-		false,
 		"exclude resources from patch files")
 
 	// Define --path flag.
 	mf.StringSliceMatcher(matcher.NewPathMatcher,
 		"path",
-		nil,
 		"include resources by file path")
 
 	// Define --not-path flag.
 	mf.StringSliceMatcher(matcher.NewPathMatcher,
 		"not-path",
-		nil,
 		"exclude resources by file path")
 
 	// Define --references flag.
-	mf.StringSliceErrorMatcher(matcher.NewReferenceMatcher,
+	mf.StringSliceMatcher(matcher.NewReferenceMatcher,
 		"references",
-		nil,
 		"include resources that reference resource")
 
 	// Define --not-references flag.
-	mf.StringSliceErrorMatcher(matcher.NewReferenceMatcher,
+	mf.StringSliceMatcher(matcher.NewReferenceMatcher,
 		"not-references",
-		nil,
 		"exclude resources that reference resource")
 
 	// Define --selector flag.
-	mf.StringErrorMatcher(matcher.NewSelectorMatcher,
+	mf.StringMatcher(matcher.NewSelectorMatcher,
 		"selector",
-		"",
 		"include resources by label selector")
 
 	// Define --not-selector flag.
-	mf.StringErrorMatcher(matcher.NewSelectorMatcher,
+	mf.StringMatcher(matcher.NewSelectorMatcher,
 		"not-selector",
-		"",
 		"exclude resources by label selector")
 
 	// Define --config flag.

cmd/mflag/flags.go

@@ -75,8 +75,8 @@ func (m *FlagSet) Matcher() (matcher.Matcher, error) {
 
 // BoolMatcher creates a named bool flag paired with the given matcher.Matcher
 // constructor.
-func (m *FlagSet) BoolMatcher(callback func() matcher.Matcher, name string, value bool, usage string) {
-	result := m.flags.Bool(name, value, usage)
+func (m *FlagSet) BoolMatcher(callback func() matcher.Matcher, name string, usage string) {
+	result := m.flags.Bool(name, false, usage)
 
 	fn := func() ([]matcher.Matcher, error) {
 		if !*result {
@@ -89,10 +89,10 @@ func (m *FlagSet) BoolMatcher(callback func() matcher.Matcher, name string, valu
 	m.add(name, fn)
 }
 
-// StringErrorMatcher creates a named string flag paired with the given
+// StringMatcher creates a named string flag paired with the given
 // matcher.Matcher constructor (which can return an error).
-func (m *FlagSet) StringErrorMatcher(callback func(string) (matcher.Matcher, error), name string, value string, usage string) {
-	result := m.flags.String(name, value, usage)
+func (m *FlagSet) StringMatcher(callback func(string) (matcher.Matcher, error), name string, usage string) {
+	result := m.flags.String(name, "", usage)
 
 	fn := func() ([]matcher.Matcher, error) {
 		if *result == "" {
@@ -110,18 +110,10 @@ func (m *FlagSet) StringErrorMatcher(callback func(string) (matcher.Matcher, err
 	m.add(name, fn)
 }
 
-// StringSliceMatcher creates a named string slice flag paired with the given
-// matcher.Matcher constructor.
-func (m *FlagSet) StringSliceMatcher(callback func(string) matcher.Matcher, name string, value []string, usage string) {
-	m.StringSliceErrorMatcher(func(s string) (matcher.Matcher, error) {
-		return callback(s), nil
-	}, name, value, usage)
-}
-
-// StringSliceErrorMatcher creates a named string slice flag paired with the
+// StringSliceMatcher creates a named string slice flag paired with the
 // given matcher.Matcher constructor (which can return an error).
-func (m *FlagSet) StringSliceErrorMatcher(callback func(string) (matcher.Matcher, error), name string, value []string, usage string) {
-	results := m.flags.StringSlice(name, value, usage)
+func (m *FlagSet) StringSliceMatcher(callback func(string) (matcher.Matcher, error), name string, usage string) {
+	results := m.flags.StringSlice(name, nil, usage)
 
 	fn := func() ([]matcher.Matcher, error) {
 		if len(*results) == 0 {

matcher/matcher-contains.go

@@ -18,8 +18,8 @@ import (
 // to resources that were originally decoded from JSON files. Additionally,
 // these re-marshalled YAML documents no longer contain any of the original
 // comments or other formatting.
-func NewContainsMatcher(substring string) Matcher {
-	return containsMatcher{substring: substring}
+func NewContainsMatcher(substring string) (Matcher, error) {
+	return containsMatcher{substring: substring}, nil
 }
 
 type containsMatcher struct {

matcher/matcher-contains_test.go

@@ -17,12 +17,12 @@ func TestContainsMatcher(t *testing.T) {
 	testMatcher(t, []spec{
 		{
 			title:   "image substring",
-			matcher: matcher.NewContainsMatcher("mage: gcr.io/goog"),
+			matcher: must(matcher.NewContainsMatcher("mage: gcr.io/goog")),
 			matches: []string{"Pod/test-pod"},
 		},
 		{
 			title:   "port substring",
-			matcher: matcher.NewContainsMatcher("ort: 80"),
+			matcher: must(matcher.NewContainsMatcher("ort: 80")),
 			matches: []string{
 				"Deployment/nginx-deployment",
 				"Service/my-service",

matcher/matcher-path.go

@@ -17,8 +17,8 @@ import (
 // For example, a resource decoded from the file
 // `kustomize/environments/production/deployment.yaml` would be matched by the
 // input `environments/production` or `deployment.yaml`.
-func NewPathMatcher(path string) Matcher {
-	return pathMatcher{path: path}
+func NewPathMatcher(path string) (Matcher, error) {
+	return pathMatcher{path: path}, nil
 }
 
 type pathMatcher struct {

matcher/matcher-path_test.go

@@ -17,7 +17,7 @@ func TestPathMatcher(t *testing.T) {
 	testMatcher(t, []spec{
 		{
 			title:   "files under subdir",
-			matcher: matcher.NewPathMatcher("/subdir/"),
+			matcher: must(matcher.NewPathMatcher("/subdir/")),
 			matches: []string{
 				"ClusterRoleBinding/read-secrets-global",
 				"Deployment/nginx-deployment",
@@ -26,7 +26,7 @@ func TestPathMatcher(t *testing.T) {
 		},
 		{
 			title:   "files under subsubdir",
-			matcher: matcher.NewPathMatcher("/subdir/subsubdir"),
+			matcher: must(matcher.NewPathMatcher("/subdir/subsubdir")),
 			matches: []string{"ConfigMap/my-configmap"},
 		},
 	})