private/apigen: Support Go generics (TypeScript)

This commit fixes the TypeScript API generator to generate correct names
from Go structs that use generics.

Change-Id: Ic512b8ac3eae19fe2a27f7e9508ad679f86389c3

private/apigen/common.go

@@ -219,3 +219,7 @@ func parseJSONTag(structType reflect.Type, field reflect.StructField) (_ jsonTag
 
 	return info, true, nil
 }
+
+func typeNameWithoutGenerics(n string) string {
+	return strings.SplitN(n, "[", 2)[0]
+}

private/apigen/example/api.gen.go

@@ -35,6 +35,7 @@ type DocumentsService interface {
 type UsersService interface {
 	Get(ctx context.Context) ([]myapi.User, api.HTTPError)
 	Create(ctx context.Context, request []myapi.User) api.HTTPError
+	GetAge(ctx context.Context) (*myapi.UserAge[int16], api.HTTPError)
 }
 
 // DocumentsHandler is an api handler that implements all Documents API endpoints functionality.
@@ -80,6 +81,7 @@ func NewUsers(log *zap.Logger, mon *monkit.Scope, service UsersService, router *
 	usersRouter := router.PathPrefix("/api/v0/users").Subrouter()
 	usersRouter.HandleFunc("/", handler.handleGet).Methods("GET")
 	usersRouter.HandleFunc("/", handler.handleCreate).Methods("POST")
+	usersRouter.HandleFunc("/age", handler.handleGetAge).Methods("GET")
 
 	return handler
 }
@@ -304,3 +306,22 @@ func (h *UsersHandler) handleCreate(w http.ResponseWriter, r *http.Request) {
 		api.ServeError(h.log, w, httpErr.Status, httpErr.Err)
 	}
 }
+
+func (h *UsersHandler) handleGetAge(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+	var err error
+	defer h.mon.Task()(&ctx)(&err)
+
+	w.Header().Set("Content-Type", "application/json")
+
+	retVal, httpErr := h.service.GetAge(ctx)
+	if httpErr.Err != nil {
+		api.ServeError(h.log, w, httpErr.Status, httpErr.Err)
+		return
+	}
+
+	err = json.NewEncoder(w).Encode(retVal)
+	if err != nil {
+		h.log.Debug("failed to write json GetAge response", zap.Error(ErrUsersAPI.Wrap(err)))
+	}
+}

private/apigen/example/apidocs.gen.md

@@ -13,6 +13,7 @@
 * Users
   * [Get Users](#users-get-users)
   * [Create Users](#users-create-users)
+  * [Get User's age](#users-get-users-age)
 
 <h3 id='documents-get-documents'>Get Documents (<a href='#list-of-endpoints'>go to full list</a>)</h3>
 
@@ -226,3 +227,20 @@ Create users
 
 ```
 
+<h3 id='users-get-users-age'>Get User's age (<a href='#list-of-endpoints'>go to full list</a>)</h3>
+
+Get the user's age
+
+`GET /api/v0/users/age`
+
+**Response body:**
+
+```typescript
+{
+	day: number
+	month: number
+	year: number
+}
+
+```
+

private/apigen/example/client-api-mock.gen.ts

@@ -28,6 +28,12 @@ export class User {
     position: string;
 }
 
+export class UserAge {
+    day: number;
+    month: number;
+    year: number;
+}
+
 export class Version {
     date: Time;
     number: number;
@@ -136,4 +142,12 @@ export class UsersHttpApiV0 {
 
         return;
     }
+
+    public async getAge(): Promise<UserAge> {
+        if (this.respStatusCode !== 0) {
+            throw new APIError('mock error message: ' + this.respStatusCode, this.respStatusCode);
+        }
+
+        return JSON.parse('{"day":1,"month":1,"year":2000}') as UserAge;
+    }
 }

private/apigen/example/client-api.gen.ts

@@ -30,6 +30,12 @@ export class User {
     position: string;
 }
 
+export class UserAge {
+    day: number;
+    month: number;
+    year: number;
+}
+
 export class Version {
     date: Time;
     number: number;
@@ -125,4 +131,14 @@ export class UsersHttpApiV0 {
         const err = await response.json();
         throw new APIError(err.error, response.status);
     }
+
+    public async getAge(): Promise<UserAge> {
+        const fullPath = `${this.ROOT_PATH}/age`;
+        const response = await this.http.get(fullPath);
+        if (response.ok) {
+            return response.json().then((body) => body as UserAge);
+        }
+        const err = await response.json();
+        throw new APIError(err.error, response.status);
+    }
 }

private/apigen/example/gen.go

@@ -159,6 +159,15 @@ func main() {
 		Request:        []myapi.User{},
 	})
 
+	g.Get("/age", &apigen.Endpoint{
+		Name:           "Get User's age",
+		Description:    "Get the user's age",
+		GoName:         "GetAge",
+		TypeScriptName: "getAge",
+		Response:       myapi.UserAge[int16]{},
+		ResponseMock:   myapi.UserAge[int16]{Day: 1, Month: 1, Year: 2000},
+	})
+
 	a.MustWriteGo("api.gen.go")
 	a.MustWriteTS("client-api.gen.ts")
 	a.MustWriteTSMock("client-api-mock.gen.ts")

private/apigen/example/myapi/types.go

@@ -49,3 +49,14 @@ type Professional struct {
 	Company  string `json:"company"`
 	Position string `json:"position"`
 }
+
+// UserAge represents a user's age.
+//
+// The value is generic for being able to increase the year's size to afford to recompile the code
+// when we have users that were born in a too far DC year or allow to register users in a few years
+// in the future. JOKING, we need it for testing that the API generator works fine with them.
+type UserAge[T ~int16 | int32 | int64] struct {
+	Day   uint8 `json:"day"`
+	Month uint8 `json:"month"`
+	Year  T     `json:"year"`
+}

private/apigen/tstypes.go

@@ -76,7 +76,7 @@ func (types *Types) All() map[reflect.Type]string {
 				panic(fmt.Sprintf("BUG: found an anonymous 'struct'. Found type=%q", t))
 			}
 
-			all[t] = t.Name()
+			all[t] = typeNameWithoutGenerics(t.Name())
 
 			for i := 0; i < t.NumField(); i++ {
 				field := t.Field(i)
@@ -211,7 +211,7 @@ func TypescriptTypeName(t reflect.Type) string {
 		if t.Name() == "" {
 			panic(fmt.Sprintf(`anonymous struct aren't accepted because their type doesn't have a name. Type="%+v"`, t))
 		}
-		return capitalize(t.Name())
+		return capitalize(typeNameWithoutGenerics(t.Name()))
 	default:
 		panic(fmt.Sprintf(`unhandled type. Type="%+v"`, t))
 	}