Is it possible to use 'import_style' for Typescript

[wiewioraseb]

I want to have access to types when I get statically generated protobuff files.

Running code:
protoc -I=Protos --js_out=import_style=es6,binary:Javascript Protos/MessageEvnelope.proto Protos/Messages.proto

Generates .js files that are not easily imported in Typescript. When:
import { SomeMessage } from './Messages_pb';
I got error:

Could not find a declaration file for module './Messages_pb' ... implicitly has an 'any' type.

To overcome this, I have to use require('./Messages_pb') which results with no types, which does not satisfy me.

Is there an automatic way to create types for such generated js file? Or some other way to have types in typescript?

[acozzette]

I'm afraid we don't have much experience with TypeScript and so I'm not sure of the best way to handle that use case well. If you have any ideas then we would probably be open to taking pull requests, though.

[dominikeinkemmer]

@wiewioraseb we currently use this plugin to generate the typescript typings, maybe it helps you?
It basically generates .d.ts files for all javascript files.
https://github.com/improbable-eng/ts-protoc-gen

[clehene]

@dominikeinkemmer would it make sense to name the issue "TypeScript Support"?

@acozzette note that grpc-web already implemented Typescript support - see here https://github.com/grpc/grpc-web#typescript-support

@dominikeinkemmer In order to get the definitions working it's possible to just create a dummy gRPC service that depends on some protobuf hierarchy and using

import_style=commonjs+dts: existing CommonJS style stub + .d.ts typings
import_style=typescript: full TypeScript output

will work.
My suggestion is to start from the existing plugin (https://github.com/grpc/grpc-web/blob/master/javascript/net/grpc/web/grpc_generator.cc) or from one of the various implementations out there, but regardless it should be consistent between protocol buffers and grpc at least.

As an additional note, it would also be nice to support a fluent API and have some thinking around JS / TS number type vs the variety that protobuf supports.

Reference

https://github.com/dcodeIO/ProtoBuf.js/#usage-with-typescript
https://github.com/improbable-eng/ts-protoc-gen
https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/google-protobuf/google/protobuf

[clehene]

This is related / duplicates #98

[acozzette]

I haven't worked on Javascript in a while but @dankurka and @TeBoring might have thoughts on this.

[grzpotry]

Is workaround with gRPC service still necessary just to import generated files with type definitions to typescript ?

[thesayyn]

For this particular problem, we have created a plugin that generates typescript sources. You do not need to depend on js generator or ts-protoc-gen. It is just pure typescript sources that work out-of-the-box.

This might solve your problem.

https://github.com/thesayyn/protoc-gen-ts

[chris-kruining]

I've made a PR for "native" Typescript support over at protocolbuffers/protobuf#9412.

Any help is more than welcome, I am way out of my depth in c++

[dibenede]

Duplicate of #98