github.com/googleapis/api-linter@v1.65.2/rules/aip0135/response_message_name.go (about)

     1  // Copyright 2019 Google LLC
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     https://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package aip0135
    16  
    17  import (
    18  	"fmt"
    19  	"strings"
    20  
    21  	"bitbucket.org/creachadair/stringset"
    22  	"github.com/googleapis/api-linter/lint"
    23  	"github.com/googleapis/api-linter/locations"
    24  	"github.com/googleapis/api-linter/rules/internal/utils"
    25  	"github.com/jhump/protoreflect/desc"
    26  )
    27  
    28  // Delete messages should use google.protobuf.Empty,
    29  // google.longrunning.Operation, or the resource itself as the response
    30  // message.
    31  var responseMessageName = &lint.MethodRule{
    32  	Name:   lint.NewRuleName(135, "response-message-name"),
    33  	OnlyIf: utils.IsDeleteMethod,
    34  	LintMethod: func(m *desc.MethodDescriptor) []lint.Problem {
    35  		resource := strings.Replace(m.GetName(), "Delete", "", 1)
    36  
    37  		// Rule check: Establish that for methods such as `DeleteFoo`, the response
    38  		// message is `google.protobuf.Empty` or `Foo`.
    39  		got := m.GetOutputType().GetName()
    40  		if stringset.New("Empty", "Operation").Contains(got) {
    41  			got = m.GetOutputType().GetFullyQualifiedName()
    42  		}
    43  		want := stringset.New(resource, "google.protobuf.Empty")
    44  
    45  		// If the return type is an Operation, use the annotated response type.
    46  		lro := false
    47  		if utils.IsOperation(m.GetOutputType()) {
    48  			got = utils.GetOperationInfo(m).GetResponseType()
    49  			lro = true
    50  		}
    51  
    52  		// If we did not get a permitted value, return a problem.
    53  		//
    54  		// Note: If `got` is empty string, this is an unannotated LRO.
    55  		// The AIP-151 rule will whine about that, and this rule should not as it
    56  		// would be confusing.
    57  		if !want.Contains(got) && got != "" {
    58  			// Customize the error message (by including Empty iff the resource is
    59  			// not marked declarative-friendly)
    60  			msg := "Delete RPCs should have response message type of Empty or the resource, not %q."
    61  			suggestion := "google.protobuf.Empty"
    62  
    63  			// Customize the location based on whether an LRO is in use.
    64  			location := locations.MethodResponseType(m)
    65  			if lro {
    66  				location = locations.MethodOperationInfo(m)
    67  				suggestion = "" // We can not offer a precise enough location to make a suggestion.
    68  			}
    69  
    70  			// Create and return the problem.
    71  			problem := lint.Problem{
    72  				Message:    fmt.Sprintf(msg, got),
    73  				Descriptor: m,
    74  				Location:   location,
    75  			}
    76  			if len(suggestion) > 0 {
    77  				problem.Suggestion = suggestion
    78  			}
    79  			return []lint.Problem{problem}
    80  		}
    81  
    82  		return nil
    83  	},
    84  }