redwoodjs v3 tutrial 5章~

yarn rw setup tsconfig
yarn rw g types

app_1      | gen | Modified Directory named module:  web/src/components/Comment/Comment.tsx 
app_1      | api | 12:58:35 🌲 incoming request GET xxx /auth?method=getToken
app_1      | api | 12:58:35 🌲 request completed 3ms
app_1      | api | 12:58:35 🌲 incoming request POST xxx /graphql
app_1      | api | 12:58:35 🐛 Parsing request to extract GraphQL parameters
app_1      | api | 12:58:35 🐛 Processing GraphQL Parameters
app_1      | api | 12:58:35 🐛 Execution start
app_1      | api | 12:58:35 🌲 request completed 15ms
app_1      | api | 12:58:35 🐛 Received GraphQL operation:
app_1      | api | 12:58:35 🐛 undefined 
app_1      | api | 🏷  DeleteCommentMutation 
app_1      | api | 🔭 Query
app_1      | api | "mutation DeleteCommentMutation($id: Int!) {\n  deleteComment(id: $id) {\n    id\n    __typename\n  }\n}"
app_1      | api | 12:58:35 🐛 graphql-server GraphQL execution started: DeleteCommentMutation
app_1      | api | 12:58:35 🐛 Execution end
app_1      | api | 12:58:35 🐛 undefined
app_1      | api | 12:58:35 🚨 graphql-server Cannot return null for non-nullable field Mutation.deleteComment. 
app_1      | api | 
app_1      | api | 🚨 GraphQLError Info
app_1      | api | 
app_1      | api | {
app_1      | api |   "path": [
app_1      | api |     "deleteComment"
app_1      | api |   ],
app_1      | api |   "locations": [
app_1      | api |     {
app_1      | api |       "line": 2,
app_1      | api |       "column": 3
app_1      | api |     }
app_1      | api |   ],
app_1      | api |   "extensions": {}
app_1      | api | }
app_1      | api |  
app_1      | api | 🥞 Error Stack
app_1      | api | 
app_1      | api | Error: Cannot return null for non-nullable field Mutation.deleteComment.
app_1      | api |     at completeValue (/app/node_modules/graphql/execution/execute.js:594:13)
app_1      | api |     at executeField (/app/node_modules/graphql/execution/execute.js:489:19)
app_1      | api |     at /app/node_modules/graphql/execution/execute.js:377:22
app_1      | api |     at promiseReduce (/app/node_modules/graphql/jsutils/promiseReduce.js:23:9)
app_1      | api |     at executeFieldsSerially (/app/node_modules/graphql/execution/execute.js:373:43)
app_1      | api |     at executeOperation (/app/node_modules/graphql/execution/execute.js:347:14)
app_1      | api |     at execute (/app/node_modules/graphql/execution/execute.js:136:20)
app_1      | api |     at /app/node_modules/@envelop/core/cjs/orchestrator.js:380:33
app_1      | api |     at async processRequest (/app/node_modules/@graphql-yoga/common/cjs/processRequest.js:26:20)
app_1      | api |     at async YogaServer.getResponse (/app/node_modules/@graphql-yoga/common/cjs/server.js:318:28)
app_1      | api |