Add "openapi:typename" meta to user types (#3572)

This update forces OpenAPI generators to use specified type names rather than merging structurally identical types automatically.

Note: Goa-generated types (e.g., from anonymous payload or result definitions) will still be merged if structurally identical. This approach helps prevent the unnecessary proliferation of types in OpenAPI specifications.

dsl/result_type.go

@@ -116,6 +116,7 @@ func ResultType(identifier string, args ...any) *expr.ResultTypeExpr {
 	}
 	// Add the type to the generated types root for later evaluation.
 	rt := expr.NewResultTypeExpr(typeName, identifier, fn)
+	rt.Meta = expr.MetaExpr{"openapi:typename": []string{typeName}}
 	expr.Root.ResultTypes = append(expr.Root.ResultTypes, rt)
 
 	return rt

dsl/user_type.go

@@ -103,8 +103,12 @@ func Type(name string, args ...any) expr.UserType {
 	}
 
 	t := &expr.UserTypeExpr{
-		TypeName:      name,
-		AttributeExpr: &expr.AttributeExpr{Type: base, DSLFunc: fn},
+		TypeName: name,
+		AttributeExpr: &expr.AttributeExpr{
+			Type:    base,
+			DSLFunc: fn,
+			Meta:    expr.MetaExpr{"openapi:typename": []string{name}},
+		},
 	}
 	expr.Root.Types = append(expr.Root.Types, t)
 	return t

http/codegen/openapi/v2/files_test.go

@@ -13,6 +13,7 @@ import (
 
 	"github.com/getkin/kin-openapi/openapi2"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	httpgen "goa.design/goa/v3/http/codegen"
 	"goa.design/goa/v3/http/codegen/openapi"
@@ -99,15 +100,15 @@ func TestSections(t *testing.T) {
 						t.Fatalf("failed to read golden file: %s", err)
 					}
 					if !bytes.Equal(buf.Bytes(), want) {
-						var left, right string
+						var got, expected string
 						if filepath.Ext(o.Path) == ".json" {
-							left = prettifyJSON(t, buf.Bytes())
-							right = prettifyJSON(t, want)
+							got = prettifyJSON(t, buf.Bytes())
+							expected = prettifyJSON(t, want)
 						} else {
-							left = buf.String()
-							right = string(want)
+							got = buf.String()
+							expected = string(want)
 						}
-						assert.Equal(t, left, right)
+						assert.Equal(t, expected, got)
 					}
 				})
 			}
@@ -145,51 +146,32 @@ func TestValidations(t *testing.T) {
 			openapi.Definitions = make(map[string]*openapi.Schema)
 			root := httpgen.RunHTTPDSL(t, c.DSL)
 			oFiles, err := openapiv2.Files(root)
-			if err != nil {
-				t.Fatalf("OpenAPI failed with %s", err)
-			}
-			if len(oFiles) == 0 {
-				t.Fatalf("No swagger files")
-			}
+			require.NoError(t, err, "OpenAPI failed")
+			require.NotEmpty(t, oFiles, "No swagger files")
 			for i, o := range oFiles {
 				tname := fmt.Sprintf("file%d", i)
 				s := o.SectionTemplates
 				t.Run(tname, func(t *testing.T) {
-					if len(s) != 1 {
-						t.Fatalf("expected 1 section, got %d", len(s))
-					}
-					if s[0].Source == "" {
-						t.Fatalf("empty section template")
-					}
-					if s[0].Data == nil {
-						t.Fatalf("nil data")
-					}
+					require.Len(t, s, 1, "expected 1 section, got %d", len(s))
+					require.NotEmpty(t, s[0].Source, "empty section template")
+					require.NotNil(t, s[0].Data, "nil data")
 					var buf bytes.Buffer
 					tmpl := template.Must(template.New("openapi").Funcs(s[0].FuncMap).Parse(s[0].Source))
-					if err := tmpl.Execute(&buf, s[0].Data); err != nil {
-						t.Fatalf("failed to render template: %s", err)
-					}
+					require.NoError(t, tmpl.Execute(&buf, s[0].Data), "failed to render template")
 					if filepath.Ext(o.Path) == ".json" {
-						if err := validateSwagger(buf.Bytes()); err != nil {
-							t.Fatalf("invalid swagger: %s", err)
-						}
+						require.NoError(t, validateSwagger(buf.Bytes()), "invalid swagger")
 					}
 
 					golden := filepath.Join(goldenPath, fmt.Sprintf("%s_%s.golden", c.Name, tname))
 					if *update {
-						if err := os.WriteFile(golden, buf.Bytes(), 0644); err != nil {
-							t.Fatalf("failed to update golden file: %s", err)
-						}
+						require.NoError(t, os.WriteFile(golden, buf.Bytes(), 0644), "failed to update golden file")
+						return
 					}
 
 					want, err := os.ReadFile(golden)
+					require.NoError(t, err, "failed to read golden file")
 					want = bytes.ReplaceAll(want, []byte{'\r', '\n'}, []byte{'\n'})
-					if err != nil {
-						t.Fatalf("failed to read golden file: %s", err)
-					}
-					if !bytes.Equal(buf.Bytes(), want) {
-						t.Errorf("result do not match the golden file:\n--BEGIN--\n%s\n--END--\n", buf.Bytes())
-					}
+					assert.Equal(t, string(want), buf.String())
 				})
 			}
 		})
@@ -212,51 +194,32 @@ func TestExtensions(t *testing.T) {
 			openapi.Definitions = make(map[string]*openapi.Schema)
 			root := httpgen.RunHTTPDSL(t, c.DSL)
 			oFiles, err := openapiv2.Files(root)
-			if err != nil {
-				t.Fatalf("OpenAPI failed with %s", err)
-			}
-			if len(oFiles) == 0 {
-				t.Fatalf("No swagger files")
-			}
+			require.NoError(t, err, "OpenAPI failed")
+			require.NotEmpty(t, oFiles, "No swagger files")
 			for i, o := range oFiles {
 				tname := fmt.Sprintf("file%d", i)
 				s := o.SectionTemplates
 				t.Run(tname, func(t *testing.T) {
-					if len(s) != 1 {
-						t.Fatalf("expected 1 section, got %d", len(s))
-					}
-					if s[0].Source == "" {
-						t.Fatalf("empty section template")
-					}
-					if s[0].Data == nil {
-						t.Fatalf("nil data")
-					}
+					require.Len(t, s, 1, "expected 1 section, got %d", len(s))
+					require.NotEmpty(t, s[0].Source, "empty section template")
+					require.NotNil(t, s[0].Data, "nil data")
 					var buf bytes.Buffer
 					tmpl := template.Must(template.New("openapi").Funcs(s[0].FuncMap).Parse(s[0].Source))
-					if err := tmpl.Execute(&buf, s[0].Data); err != nil {
-						t.Fatalf("failed to render template: %s", err)
-					}
+					require.NoError(t, tmpl.Execute(&buf, s[0].Data), "failed to render template")
 					if filepath.Ext(o.Path) == ".json" {
-						if err := validateSwagger(buf.Bytes()); err != nil {
-							t.Fatalf("invalid swagger: %s", err)
-						}
+						require.NoError(t, validateSwagger(buf.Bytes()), "invalid swagger")
 					}
 
 					golden := filepath.Join(goldenPath, fmt.Sprintf("%s_%s.golden", c.Name, tname))
 					if *update {
-						if err := os.WriteFile(golden, buf.Bytes(), 0644); err != nil {
-							t.Fatalf("failed to update golden file: %s", err)
-						}
+						require.NoError(t, os.WriteFile(golden, buf.Bytes(), 0644), "failed to update golden file")
+						return
 					}
 
 					want, err := os.ReadFile(golden)
 					want = bytes.ReplaceAll(want, []byte{'\r', '\n'}, []byte{'\n'})
-					if err != nil {
-						t.Fatalf("failed to read golden file: %s", err)
-					}
-					if !bytes.Equal(buf.Bytes(), want) {
-						t.Errorf("result do not match the golden file:\n--BEGIN--\n%s\n--END--\n", buf.Bytes())
-					}
+					require.NoError(t, err, "failed to read golden file")
+					assert.Equal(t, string(want), buf.String())
 				})
 			}
 		})

http/codegen/openapi/v2/testdata/TestExtensions/endpoint_file0.golden

@@ -1 +1 @@
-{"swagger":"2.0","info":{"title":"","version":"0.0.1","x-test-api":"API"},"host":"goa.design","consumes":["application/json","application/xml","application/gob"],"produces":["application/json","application/xml","application/gob"],"paths":{"/":{"post":{"operationId":"testService#testEndpoint","parameters":[{"in":"body","name":"TestEndpointRequestBody","required":true,"schema":{"$ref":"#/definitions/TestServiceTestEndpointRequestBody"}}],"responses":{"200":{"description":"OK response.","schema":{"$ref":"#/definitions/TestServiceTestEndpointResponseBody"}}},"schemes":["https"],"summary":"testEndpoint testService","tags":["testService"],"x-test-operation":"Operation"},"x-test-foo":"bar"}},"definitions":{"TestServiceTestEndpointRequestBody":{"title":"TestServiceTestEndpointRequestBody","type":"object","properties":{"string":{"example":"","type":"string","x-test-schema":"Payload"}},"example":{"string":""}},"TestServiceTestEndpointResponseBody":{"title":"TestServiceTestEndpointResponseBody","type":"object","properties":{"string":{"example":"","type":"string","x-test-schema":"Result"}},"example":{"string":""}}},"tags":[{"description":"Description of Backend","externalDocs":{"description":"See more docs here","url":"http://example.com"},"name":"Backend","x-data":{"foo":"bar"}}]}
+{"swagger":"2.0","info":{"title":"","version":"0.0.1","x-test-api":"API"},"host":"goa.design","consumes":["application/json","application/xml","application/gob"],"produces":["application/json","application/xml","application/gob"],"paths":{"/":{"post":{"operationId":"testService#testEndpoint","parameters":[{"in":"body","name":"TestEndpointRequestBody","required":true,"schema":{"$ref":"#/definitions/Payload"}}],"responses":{"200":{"description":"OK response.","schema":{"$ref":"#/definitions/Result"}}},"schemes":["https"],"summary":"testEndpoint testService","tags":["testService"],"x-test-operation":"Operation"},"x-test-foo":"bar"}},"definitions":{"Payload":{"title":"Payload","type":"object","properties":{"string":{"example":"","type":"string","x-test-schema":"Payload"}},"example":{"string":""}},"Result":{"title":"Result","type":"object","properties":{"string":{"example":"","type":"string","x-test-schema":"Result"}},"example":{"string":""}}},"tags":[{"description":"Description of Backend","externalDocs":{"description":"See more docs here","url":"http://example.com"},"name":"Backend","x-data":{"foo":"bar"}}]}

http/codegen/openapi/v2/testdata/TestExtensions/endpoint_file1.golden

@@ -21,12 +21,12 @@ paths:
                   name: TestEndpointRequestBody
                   required: true
                   schema:
-                    $ref: '#/definitions/TestServiceTestEndpointRequestBody'
+                    $ref: '#/definitions/Payload'
             responses:
                 "200":
                     description: OK response.
                     schema:
-                        $ref: '#/definitions/TestServiceTestEndpointResponseBody'
+                        $ref: '#/definitions/Result'
             schemes:
                 - https
             summary: testEndpoint testService
@@ -35,8 +35,8 @@ paths:
             x-test-operation: Operation
         x-test-foo: bar
 definitions:
-    TestServiceTestEndpointRequestBody:
-        title: TestServiceTestEndpointRequestBody
+    Payload:
+        title: Payload
         type: object
         properties:
             string:
@@ -45,8 +45,8 @@ definitions:
                 x-test-schema: Payload
         example:
             string: ""
-    TestServiceTestEndpointResponseBody:
-        title: TestServiceTestEndpointResponseBody
+    Result:
+        title: Result
         type: object
         properties:
             string:

http/codegen/openapi/v2/testdata/TestSections/multiple-services_file0.golden

@@ -1 +1 @@
-{"swagger":"2.0","info":{"title":"","version":"0.0.1"},"host":"goa.design","consumes":["application/json","application/xml","application/gob"],"produces":["application/json","application/xml","application/gob"],"paths":{"/":{"get":{"tags":["testService"],"summary":"testEndpoint testService","operationId":"testService#testEndpoint","parameters":[{"name":"TestEndpointRequestBody","in":"body","required":true,"schema":{"$ref":"#/definitions/TestServiceTestEndpointRequestBody"}}],"responses":{"200":{"description":"OK response.","schema":{"$ref":"#/definitions/TestServiceTestEndpointResponseBody"}}},"schemes":["https"]},"post":{"tags":["anotherTestService"],"summary":"testEndpoint anotherTestService","operationId":"anotherTestService#testEndpoint","parameters":[{"name":"TestEndpointRequestBody","in":"body","required":true,"schema":{"$ref":"#/definitions/AnotherTestServiceTestEndpointRequestBody"}}],"responses":{"200":{"description":"OK response.","schema":{"$ref":"#/definitions/AnotherTestServiceTestEndpointResponseBody"}}},"schemes":["https"]}}},"definitions":{"AnotherTestServiceTestEndpointRequestBody":{"title":"AnotherTestServiceTestEndpointRequestBody","type":"object","properties":{"string":{"type":"string","example":""}},"example":{"string":""}},"AnotherTestServiceTestEndpointResponseBody":{"title":"AnotherTestServiceTestEndpointResponseBody","type":"object","properties":{"string":{"type":"string","example":""}},"example":{"string":""}},"TestServiceTestEndpointRequestBody":{"title":"TestServiceTestEndpointRequestBody","type":"object","properties":{"string":{"type":"string","example":""}},"example":{"string":""}},"TestServiceTestEndpointResponseBody":{"title":"TestServiceTestEndpointResponseBody","type":"object","properties":{"string":{"type":"string","example":""}},"example":{"string":""}}}}
+{"swagger":"2.0","info":{"title":"","version":"0.0.1"},"host":"goa.design","consumes":["application/json","application/xml","application/gob"],"produces":["application/json","application/xml","application/gob"],"paths":{"/":{"get":{"tags":["testService"],"summary":"testEndpoint testService","operationId":"testService#testEndpoint","parameters":[{"name":"TestEndpointRequestBody","in":"body","required":true,"schema":{"$ref":"#/definitions/Payload"}}],"responses":{"200":{"description":"OK response.","schema":{"$ref":"#/definitions/Result"}}},"schemes":["https"]},"post":{"tags":["anotherTestService"],"summary":"testEndpoint anotherTestService","operationId":"anotherTestService#testEndpoint","parameters":[{"name":"TestEndpointRequestBody","in":"body","required":true,"schema":{"$ref":"#/definitions/Payload"}}],"responses":{"200":{"description":"OK response.","schema":{"$ref":"#/definitions/Result"}}},"schemes":["https"]}}},"definitions":{"Payload":{"title":"Payload","type":"object","properties":{"string":{"type":"string","example":""}},"example":{"string":""}},"Result":{"title":"Result","type":"object","properties":{"string":{"type":"string","example":""}},"example":{"string":""}}}}

http/codegen/openapi/v2/testdata/TestSections/multiple-services_file1.golden

@@ -23,12 +23,12 @@ paths:
                   in: body
                   required: true
                   schema:
-                    $ref: '#/definitions/TestServiceTestEndpointRequestBody'
+                    $ref: '#/definitions/Payload'
             responses:
                 "200":
                     description: OK response.
                     schema:
-                        $ref: '#/definitions/TestServiceTestEndpointResponseBody'
+                        $ref: '#/definitions/Result'
             schemes:
                 - https
         post:
@@ -41,44 +41,26 @@ paths:
                   in: body
                   required: true
                   schema:
-                    $ref: '#/definitions/AnotherTestServiceTestEndpointRequestBody'
+                    $ref: '#/definitions/Payload'
             responses:
                 "200":
                     description: OK response.
                     schema:
-                        $ref: '#/definitions/AnotherTestServiceTestEndpointResponseBody'
+                        $ref: '#/definitions/Result'
             schemes:
                 - https
 definitions:
-    AnotherTestServiceTestEndpointRequestBody:
-        title: AnotherTestServiceTestEndpointRequestBody
+    Payload:
+        title: Payload
         type: object
         properties:
             string:
                 type: string
                 example: ""
         example:
             string: ""
-    AnotherTestServiceTestEndpointResponseBody:
-        title: AnotherTestServiceTestEndpointResponseBody
-        type: object
-        properties:
-            string:
-                type: string
-                example: ""
-        example:
-            string: ""
-    TestServiceTestEndpointRequestBody:
-        title: TestServiceTestEndpointRequestBody
-        type: object
-        properties:
-            string:
-                type: string
-                example: ""
-        example:
-            string: ""
-    TestServiceTestEndpointResponseBody:
-        title: TestServiceTestEndpointResponseBody
+    Result:
+        title: Result
         type: object
         properties:
             string:

http/codegen/openapi/v2/testdata/TestSections/multiple-views_file0.golden

@@ -1 +1 @@
-{"swagger":"2.0","info":{"title":"","version":"0.0.1"},"host":"localhost:80","consumes":["application/json","application/xml","application/gob"],"produces":["application/json","application/xml","application/gob"],"paths":{"/":{"get":{"tags":["testService"],"summary":"testEndpointDefault testService","operationId":"testService#testEndpointDefault","produces":["application/custom+json"],"responses":{"200":{"description":"OK response.","schema":{"$ref":"#/definitions/TestServiceTestEndpointDefaultResponseBody"}}},"schemes":["http"]}},"/tiny":{"get":{"tags":["testService"],"summary":"testEndpointTiny testService","operationId":"testService#testEndpointTiny","responses":{"200":{"description":"OK response.","schema":{"$ref":"#/definitions/TestServiceTestEndpointTinyResponseBodyTiny"}}},"schemes":["http"]}}},"definitions":{"TestServiceTestEndpointDefaultResponseBody":{"title":"Mediatype identifier: application/json; view=default","type":"object","properties":{"int":{"type":"integer","example":1,"format":"int64"},"string":{"type":"string","example":""}},"description":"TestEndpointDefaultResponseBody result type (default view)","example":{"int":1,"string":""}},"TestServiceTestEndpointTinyResponseBodyTiny":{"title":"Mediatype identifier: application/json; view=tiny","type":"object","properties":{"string":{"type":"string","example":""}},"description":"TestEndpointTinyResponseBody result type (tiny view) (default view)","example":{"string":""}}}}
+{"swagger":"2.0","info":{"title":"","version":"0.0.1"},"host":"localhost:80","consumes":["application/json","application/xml","application/gob"],"produces":["application/json","application/xml","application/gob"],"paths":{"/":{"get":{"tags":["testService"],"summary":"testEndpointDefault testService","operationId":"testService#testEndpointDefault","produces":["application/custom+json"],"responses":{"200":{"description":"OK response.","schema":{"$ref":"#/definitions/JSON"}}},"schemes":["http"]}},"/tiny":{"get":{"tags":["testService"],"summary":"testEndpointTiny testService","operationId":"testService#testEndpointTiny","responses":{"200":{"description":"OK response.","schema":{"$ref":"#/definitions/TestServiceTestEndpointTinyResponseBodyTiny"}}},"schemes":["http"]}}},"definitions":{"JSON":{"title":"Mediatype identifier: application/json; view=default","type":"object","properties":{"int":{"type":"integer","example":1,"format":"int64"},"string":{"type":"string","example":""}},"description":"TestEndpointDefaultResponseBody result type (default view)","example":{"int":1,"string":""}},"TestServiceTestEndpointTinyResponseBodyTiny":{"title":"Mediatype identifier: application/json; view=tiny","type":"object","properties":{"string":{"type":"string","example":""}},"description":"TestEndpointTinyResponseBody result type (tiny view) (default view)","example":{"string":""}}}}

http/codegen/openapi/v2/testdata/TestSections/multiple-views_file1.golden

@@ -24,7 +24,7 @@ paths:
                 "200":
                     description: OK response.
                     schema:
-                        $ref: '#/definitions/TestServiceTestEndpointDefaultResponseBody'
+                        $ref: '#/definitions/JSON'
             schemes:
                 - http
     /tiny:
@@ -41,7 +41,7 @@ paths:
             schemes:
                 - http
 definitions:
-    TestServiceTestEndpointDefaultResponseBody:
+    JSON:
         title: 'Mediatype identifier: application/json; view=default'
         type: object
         properties: