feat(AIP-156): allow singleton list (#1230)

Author: noahdietz

docs/rules/0156/forbidden-methods.md

@@ -2,23 +2,23 @@
 rule:
   aip: 156
   name: [core, '0156', forbidden-methods]
-  summary: Singletons must not define List, Create, or Delete methods.
+  summary: Singletons must not define Create, or Delete methods.
 permalink: /156/forbidden-methods
 redirect_from:
   - /0156/forbidden-methods
 ---
 
 # Singletons: Forbidden methods
 
-This rule enforces that singleton resources do not define `List`, `Create`, or
-`Delete` methods, as mandated in [AIP-156][].
+This rule enforces that singleton resources do not define `Create`, or `Delete`
+methods, as mandated in [AIP-156][].
 
 ## Details
 
 This rule looks at any message with a `name` variable in the URI where the name
 ends in anything other than `*`. It assumes that this is a method operating on
-a singleton resource, and complains if the method is a `List`, `Create`, or
-`Delete` standard method.
+a singleton resource, and complains if the method is a `Create`, or `Delete`
+standard method.
 
 ## Examples
 

rules/aip0156/forbidden_methods.go

@@ -42,8 +42,8 @@ var forbiddenMethods = &lint.MethodRule{
 		return false
 	},
 	LintMethod: func(m *desc.MethodDescriptor) []lint.Problem {
-		// Singletons should not use Create, List, or Delete.
-		for _, badPrefix := range []string{"Create", "List", "Delete"} {
+		// Singletons should not use Create, or Delete.
+		for _, badPrefix := range []string{"Create", "Delete"} {
 			if strings.HasPrefix(m.GetName(), badPrefix) {
 				return []lint.Problem{{
 					Message:    fmt.Sprintf("Singletons must not define %q methods.", badPrefix),

rules/aip0156/forbidden_methods_test.go

@@ -29,8 +29,8 @@ func TestForbiddenMethods(t *testing.T) {
 	}{
 		{"ValidGet", "GetPublisherSettings", "/settings", testutils.Problems{}},
 		{"ValidUpdate", "UpdatePublisherSettings", "/settings", testutils.Problems{}},
+		{"ValidList", "ListPublisherSettings", "/settings", testutils.Problems{}},
 		{"InvalidCreate", "CreatePublisherSettings", "/settings", testutils.Problems{{Message: "Create"}}},
-		{"InvalidList", "ListPublisherSettings", "/settings", testutils.Problems{{Message: "List"}}},
 		{"InvalidDelete", "DeletePublisherSettings", "/settings", testutils.Problems{{Message: "Delete"}}},
 		{"Irrelevant", "CreatePublisher", "", testutils.Problems{}},
 	} {