Upload in GraphQL with NestJs and ValidationPipe - upload

Question

Im trying to make file upload in my api using this strategy: https://stephen-knutter.github.io/2020-02-07-nestjs-graphql-file-upload/.
Without the ValidationPipe works, but when i enable ValidationPipe this apresent error on class-transformer:
TypeError: Promise resolver undefined is not a function
at new Promise (<anonymous>)
at TransformOperationExecutor.transform (/Users/victorassis/Workspace/barreiroclub/api/node_modules/class-transformer/TransformOperationExecutor.js:117:32)
at _loop_1 (/Users/victorassis/Workspace/barreiroclub/api/node_modules/class-transformer/TransformOperationExecutor.js:235:45)
at TransformOperationExecutor.transform (/Users/victorassis/Workspace/barreiroclub/api/node_modules/class-transformer/TransformOperationExecutor.js:260:17)
at ClassTransformer.plainToClass (/Users/victorassis/Workspace/barreiroclub/api/node_modules/class-transformer/ClassTransformer.js:17:25)
at Object.plainToClass (/Users/victorassis/Workspace/barreiroclub/api/node_modules/class-transformer/index.js:20:29)
at ValidationPipe.transform (/Users/victorassis/Workspace/barreiroclub/api/node_modules/#nestjs/common/pipes/validation.pipe.js:40:39)
at /Users/victorassis/Workspace/barreiroclub/api/node_modules/#nestjs/core/pipes/pipes-consumer.js:15:33
at processTicksAndRejections (internal/process/task_queues.js:97:5)
I searched a lot, but seens like class-transformer is abandoned, and the answers was to not use ValidationPipe with upload.
Someone pass for this and found a solution?

Answer 1

I try to follow the example you posted above and then enable the transformation of class and I got no error as you mentioned. But I met this error before when I was trying to put the wrong type of argument in the resolver.
Below is where I setup my app bootstrap:
async function bootstrap() {
const app = await NestFactory.create(AppModule);
app.enableCors({
origin: extractOrigins(app.get(ConfigService).get('CORS_ORIGINS')),
});
app.useGlobalPipes(
new ValidationPipe({
transform: true,
}),
);
app.use(graphqlUploadExpress());
await app.listen(app.get(ConfigService).get('PORT') ?? 3000);
logScaffoldApp(app);
}
bootstrap();
The resolver code:
#Mutation(() => Boolean, { nullable: true })
async uploadVocabularies(
#Args({
name: 'file',
type: () => GraphQLUpload,
})
{ createReadStream, filename }: FileUpload,
) {
console.log('attachment:', filename);
const stream = createReadStream();
stream.on('data', (chunk: Buffer) => {
console.log(chunk);
});
}
And I did get the error when I try to follow another tutorial and trying to make the argument as a Promise so then the class transformer got the same error:
#Mutation(() => Boolean, { nullable: true })
async uploadVocabularies(
#Args({
name: 'file',
type: () => GraphQLUpload,
})
attachment: Promise<FileUpload>,
) {
const { filename, createReadStream } = await attachment;
console.log('attachment:', filename);
const stream = createReadStream();
stream.on('data', (chunk: Buffer) => {
console.log(chunk);
});
}
I hope this can help you and other people who viewed this post ^^