feat: Add rule for required standard fields.

Fixes #659.

docs/rules/0148/declarative-friendly-fields.md

@@ -0,0 +1,99 @@
+---
+rule:
+  aip: 148
+  name: [core, '0148', declarative-friendly-fields]
+  summary: Declarative-friendly resources must include some standard fields.
+permalink: /148/declarative-friendly-fields
+redirect_from:
+  - /0148/declarative-friendly-fields
+---
+
+# Declarative-friendly fields
+
+This rule requires certain standard fields on declarative-friendly resources,
+as mandated in [AIP-148][].
+
+## Details
+
+This rule looks at any resource with a `google.api.resource` annotation that
+includes `style: DECLARATIVE_FRIENDLY`, and complains if it does not include
+all of the following fields:
+
+- `string name`
+- `string uid`
+- `string display_name`
+- `google.protobuf.Timestamp create_time`
+- `google.protobuf.Timestamp update_time`
+- `google.protobuf.Timestamp delete_time`
+
+## Examples
+
+**Incorrect** code for this rule:
+
+```proto
+// Incorrect.
+message Book {
+  option (google.api.resource) = {
+    type: "library.googleapis.com/Book"
+    pattern: "publishers/{publisher}/books/{book}
+    style: DECLARATIVE_FRIENDLY
+  };
+
+  string name = 1;
+  // string uid should be included!
+  string display_name = 2;
+  google.protobuf.Timestamp create_time = 3;
+  google.protobuf.Timestamp update_time = 4;
+  // google.protobuf.TImestamp delete_time should be included!
+}
+```
+
+**Correct** code for this rule:
+
+```proto
+// Correct.
+message Book {
+  option (google.api.resource) = {
+    type: "library.googleapis.com/Book"
+    pattern: "publishers/{publisher}/books/{book}
+    style: DECLARATIVE_FRIENDLY
+  };
+
+  string name = 1;
+  string uid = 2;
+  string display_name = 3;
+  google.protobuf.Timestamp create_time = 4;
+  google.protobuf.Timestamp update_time = 5;
+  google.protobuf.TImestamp delete_time = 6;
+}
+```
+
+## Disabling
+
+If you need to violate this rule, use a leading comment above the message.
+Remember to also include an [aip.dev/not-precedent][] comment explaining why.
+
+```proto
+// (-- api-linter: core::0148::declarative-friendly-fields=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}
+    style: DECLARATIVE_FRIENDLY
+  };
+
+  string name = 1;
+  // string uid should be included!
+  string display_name = 2;
+  google.protobuf.Timestamp create_time = 3;
+  google.protobuf.Timestamp update_time = 4;
+  // google.protobuf.TImestamp delete_time should be included!
+}
+```
+
+If you need to violate this rule for an entire file, place the comment at the
+top of the file.
+
+[aip-148]: https://aip.dev/148
+[aip.dev/not-precedent]: https://aip.dev/not-precedent

docs/rules/0148/human-names.md

@@ -3,9 +3,9 @@ rule:
   aip: 148
   name: [core, '0148', human-names]
   summary: Avoid imprecise terms for human names.
-permalink: /148/standardized-codes
+permalink: /148/human-names
 redirect_from:
-  - /0148/standardized-codes
+  - /0148/human-names
 ---
 
 # Human names

rules/aip0148/aip0148.go

@@ -23,6 +23,7 @@ import (
 func AddRules(r lint.RuleRegistry) error {
 	return r.Register(
 		148,
+		declarativeFriendlyRequired,
 		humanNames,
 	)
 }

rules/aip0148/declarative_friendly_fields.go

@@ -0,0 +1,72 @@
+// Copyright 2020 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 aip0148
+
+import (
+	"fmt"
+	"strings"
+
+	"bitbucket.org/creachadair/stringset"
+	"github.com/googleapis/api-linter/lint"
+	"github.com/googleapis/api-linter/rules/internal/utils"
+	"github.com/jhump/protoreflect/desc"
+)
+
+var declarativeFriendlyRequired = &lint.MessageRule{
+	Name: lint.NewRuleName(148, "declarative-friendly-required"),
+	OnlyIf: func(m *desc.MessageDescriptor) bool {
+		if resource := utils.DeclarativeFriendlyResource(m); resource == m {
+			return true
+		}
+		return false
+	},
+	LintMessage: func(m *desc.MessageDescriptor) []lint.Problem {
+		// Define the fields that are expected.
+		missingFields := stringset.New()
+		for name, typ := range reqFields {
+			f := m.FindFieldByName(name)
+			if f == nil || utils.GetTypeName(f) != typ {
+				missingFields.Add(fmt.Sprintf("%s %s", typ, name))
+			}
+		}
+		if missingFields.Len() > 0 {
+			msg := "Declarative-friendly resources must include the following fields:\n"
+			if missingFields.Len() == 1 {
+				msg = fmt.Sprintf(
+					"Declarative-friendly resources must include the `%s` field.",
+					missingFields.Unordered()[0],
+				)
+			} else {
+				for _, field := range missingFields.Elements() {
+					msg += fmt.Sprintf("  - `%s`\n", field)
+				}
+			}
+			return []lint.Problem{{
+				Message:    strings.TrimSuffix(msg, "\n"),
+				Descriptor: m,
+			}}
+		}
+		return nil
+	},
+}
+
+var reqFields = map[string]string{
+	"name":         "string",
+	"uid":          "string",
+	"display_name": "string",
+	"create_time":  "google.protobuf.Timestamp",
+	"update_time":  "google.protobuf.Timestamp",
+	"delete_time":  "google.protobuf.Timestamp",
+}

rules/aip0148/declarative_friendly_fields_test.go

@@ -0,0 +1,105 @@
+// Copyright 2020 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 aip0148
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"bitbucket.org/creachadair/stringset"
+	"github.com/googleapis/api-linter/rules/internal/testutils"
+)
+
+func TestDeclarativeFriendlyFields(t *testing.T) {
+	for _, test := range []struct {
+		name    string
+		skipped stringset.Set
+	}{
+		{"Valid", stringset.New()},
+		{"Name", stringset.New("name")},
+		{"UID", stringset.New("uid")},
+		{"DisplayName", stringset.New("display_name")},
+		{"CreateTime", stringset.New("create_time")},
+		{"UpdateTime", stringset.New("update_time")},
+		{"DeleteTime", stringset.New("delete_time")},
+		{"AllTimes", stringset.New("create_time", "update_time", "delete_time")},
+		{"Randos", stringset.New("uid", "display_name")},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			// Set up the string with the fields we will include.
+			fields := ""
+			cursor := 1
+			for fieldName, fieldType := range reqFields {
+				if !test.skipped.Contains(fieldName) {
+					fields += fmt.Sprintf("  %s %s = %d;\n", fieldType, fieldName, cursor)
+					cursor++
+				}
+			}
+
+			// Create the potential problem object for the missing fields.
+			var problems testutils.Problems
+			if test.skipped.Len() == 1 {
+				f := test.skipped.Unordered()[0]
+				problems = testutils.Problems{{
+					Message: fmt.Sprintf("must include the `%s %s` field", reqFields[f], f),
+				}}
+			} else if test.skipped.Len() > 1 {
+				missingFields := stringset.New()
+				for _, f := range test.skipped.Unordered() {
+					missingFields.Add(fmt.Sprintf("%s %s", reqFields[f], f))
+				}
+				msg := ""
+				for _, f := range missingFields.Elements() {
+					msg += fmt.Sprintf("  - `%s`\n", f)
+				}
+				problems = testutils.Problems{{Message: strings.TrimSuffix(msg, "\n")}}
+			}
+
+			// Test against declarative-friendly and standard styles.
+			for _, subtest := range []struct {
+				name     string
+				style    string
+				problems testutils.Problems
+			}{
+				{"DeclFriendly", "style: DECLARATIVE_FRIENDLY", problems},
+				{"NotDeclFriendly", "", nil},
+			} {
+				t.Run(subtest.name, func(t *testing.T) {
+					f := testutils.ParseProto3Tmpl(t, `
+						import "google/api/resource.proto";
+						import "google/protobuf/timestamp.proto";
+						message Book {
+							option (google.api.resource) = {
+								type: "library.googleapis.com/Book"
+								pattern: "publishers/{publisher}/books/{book}"
+								{{.Style}}
+							};
+							{{.Fields}}
+						}
+					`, struct {
+						Fields string
+						Style  string
+					}{Fields: fields, Style: subtest.style})
+					m := f.GetMessageTypes()[0]
+					got := declarativeFriendlyRequired.Lint(f)
+					if diff := subtest.problems.SetDescriptor(m).Diff(got); diff != "" {
+						t.Errorf(diff)
+					}
+				})
+			}
+		})
+	}
+}