feat: Require a name field in messages with google.api.resource annot…

…ations (#839)

docs/rules/0123/resource-name-field.md

@@ -0,0 +1,83 @@
+---
+rule:
+  aip: 123
+  name: [core, '0123', resource-name-field]
+  summary: Resource messages should have a `string name` field.
+permalink: /123/resource-name-field
+redirect_from:
+  - /0123/resource-name-field
+---
+
+# Resource `name` field
+
+This rule enforces that messages that appear to represent resources have a
+`string name` field, as described in [AIP-123][].
+
+## Details
+
+This rule scans all messages that have a `google.api.resource` annotation, and
+complains if the `name` field is missing or if it is any type other than
+singular `string`.
+
+## Examples
+
+**Incorrect** code for this rule:
+
+```proto
+// Incorrect: missing `string name` field.
+message Book {
+  option (google.api.resource) = {
+    type: "library.googleapis.com/Book"
+    pattern: "publishers/{publisher}/books/{book}"
+  };
+}
+```
+
+```proto
+// Incorrect.
+message Book {
+  option (google.api.resource) = {
+    type: "library.googleapis.com/Book"
+    pattern: "publishers/{publisher}/books/{book}"
+  };
+
+  // Should be `string`, not `bytes`.
+  bytes name = 1;
+}
+```
+
+**Correct** code for this rule:
+
+```proto
+// Correct.
+message Book {
+  option (google.api.resource) = {
+    type: "library.googleapis.com/Book"
+    pattern: "publishers/{publisher}/books/{book}"
+  };
+
+  string name = 1;
+}
+```
+
+## Disabling
+
+If you need to violate this rule, use a leading comment above the message, or
+above the field if it is the wrong type.
+
+```proto
+// (-- api-linter: core::0123::resource-name-field=disabled
+//     aip.dev/not-precedent: We need to do this because reasons. --)
+message Book {
+  option (google.api.resource) = {
+    type: "library.googleapis.com/Book"
+    pattern: "publishers/{publisher}/books/{book}"
+  };
+}
+```
+
+If you need to violate this rule for an entire file, place the comment at the
+top of the file.
+
+[aip-123]: http://aip.dev/123
+[aip.dev/not-precedent]: https://aip.dev/not-precedent

rules/aip0123/aip0123.go

@@ -33,6 +33,7 @@ func AddRules(r lint.RuleRegistry) error {
 		123,
 		duplicateResource,
 		resourceAnnotation,
+		resourceNameField,
 		resourcePattern,
 		resourceReferenceType,
 		resourceVariables,

rules/aip0123/resource_name_field.go

@@ -0,0 +1,26 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package aip0123
+
+import (
+	"github.com/googleapis/api-linter/lint"
+	"github.com/googleapis/api-linter/rules/internal/utils"
+)
+
+var resourceNameField = &lint.MessageRule{
+	Name:        lint.NewRuleName(123, "resource-name-field"),
+	OnlyIf:      utils.IsResource,
+	LintMessage: utils.LintFieldPresentAndSingularString("name"),
+}

rules/aip0123/resource_name_field_test.go

@@ -0,0 +1,55 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package aip0123
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/googleapis/api-linter/rules/internal/testutils"
+	"github.com/jhump/protoreflect/desc"
+)
+
+func TestResourceNameField(t *testing.T) {
+	for _, test := range []struct {
+		name     string
+		Options  string
+		Field    string
+		problems testutils.Problems
+	}{
+		{"ValidBothPresent", `option (google.api.resource) = { type: "foo" };`, `string name = 1;`, nil},
+		{"InvalidNoField", `option (google.api.resource) = { type: "foo" };`, ``, testutils.Problems{{Message: "`name`"}}},
+		{"InvalidTypeNotString", `option (google.api.resource) = { type: "foo" };`, `int32 name = 1;`, testutils.Problems{{Suggestion: "string"}}},
+		{"InvalidTypeRepeated", `option (google.api.resource) = { type: "foo" };`, `repeated string name = 1;`, testutils.Problems{{Suggestion: "string"}}},
+		{"IrrelevantNoAnnotation", ``, ``, nil},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			f := testutils.ParseProto3Tmpl(t, `
+				import "google/api/resource.proto";
+				message Book {
+					{{.Options}}
+					{{.Field}}
+				}
+			`, test)
+			var d desc.Descriptor = f.GetMessageTypes()[0]
+			if strings.HasPrefix(test.name, "InvalidType") {
+				d = f.GetMessageTypes()[0].GetFields()[0]
+			}
+			if diff := test.problems.SetDescriptor(d).Diff(resourceNameField.Lint(f)); diff != "" {
+				t.Error(diff)
+			}
+		})
+	}
+}