Nodejs bindings

[thekingofcity]

Problem description
According to the Supported APIs, Nodejs will be supported. But it is missing right now.

Problem location
./nodejs/

Suggestions for an improvement

[thekingofcity]

I want to contribute to the Nodejs bindings of the Pravega client.

Changes will be split into several PRs:

• StreamManager Nodejs StreamManager #354
• ReaderGroup and EventReader Nodejs ReaderGroup and EventReader #357
• EventWriter and tests Nodejs EventWriter #360
• Transaction and TxnWriter Nodejs transaction #383
• ByteStream?
• CI/CD (Github Actions and Npm publish) Nodejs publish #363
• Async list scopes and streams Nodejs async list scopes and streams #371

[thekingofcity]

The binding uses neon-bindings instead of wasm-bindgen.

The reason is that the latter targets pure rust logic w/o touching sys and net. It can do everything pure js scripts can do. But for sys and net, they are not allowed in the browser. Touching the system files requires a proxy using the File System Access API and making a TCP connection is somewhat impossible in the browser. Workarounds will be a WebSocket proxy at the Pravega server-side to translate WebSocket to TCP.

This is what I get when I tried the wasm-bindgen:

$ wasm-pack build --target nodejs
[INFO]: Checking for the Wasm target...
[INFO]: Compiling to Wasm...
warning: profiles for the non root package will be ignored, specify profiles at the workspace root:
package:   /home/thekingofcity/pravega-client-rust/pravegactl/Cargo.toml
workspace: /home/thekingofcity/pravega-client-rust/Cargo.toml
   Compiling socket2 v0.4.4
   Compiling slab v0.4.5
   Compiling futures-io v0.3.21
   Compiling regex-syntax v0.6.25
   Compiling fnv v1.0.7
   Compiling cfg-if v0.1.10
   Compiling base64 v0.13.0
   Compiling percent-encoding v2.1.0
error[E0583]: file not found for module `sys`
   --> /home/thekingofcity/.cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.4/src/lib.rs:124:1
    |
124 | mod sys;
    | ^^^^^^^^
    |
    = help: to create the module `sys`, create file "/home/thekingofcity/.cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.4/src/sys.rs" or "/home/thekingofcity/.cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.4/src/sys/mod.rs"

error: Socket2 doesn't support the compile target
   --> /home/thekingofcity/.cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.4/src/lib.rs:127:1
    |
127 | compile_error!("Socket2 doesn't support the compile target");
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

error[E0432]: unresolved imports `crate::sys::sa_family_t`, `crate::sys::sockaddr`, `crate::sys::sockaddr_in`, `crate::sys::sockaddr_in6`, `crate::sys::sockaddr_storage`, `crate::sys::socklen_t`, `crate::sys::AF_INET`, `crate::sys::AF_INET6`
 --> /home/thekingofcity/.cargo/registry/src/github.com-1ecc6299db9ec823/socket2-0.4.4/src/sockaddr.rs:6:5
  |
6 |     sa_family_t, sockaddr, sockaddr_in, sockaddr_in6, sockaddr_storage, socklen_t, AF_INET,
  |     ^^^^^^^^^^^  ^^^^^^^^  ^^^^^^^^^^^  ^^^^^^^^^^^^  ^^^^^^^^^^^^^^^^  ^^^^^^^^^  ^^^^^^^ no `AF_INET` in `sys`
  |     |            |         |            |             |                 |
  |     |            |         |            |             |                 no `socklen_t` in `sys`
  |     |            |         |            |             no `sockaddr_storage` in `sys`
  |     |            |         |            no `sockaddr_in6` in `sys`
  |     |            |         no `sockaddr_in` in `sys`
  |     |            no `sockaddr` in `sys`
  |     no `sa_family_t` in `sys`
7 |     AF_INET6,
  |     ^^^^^^^^ no `AF_INET6` in `sys`

Similar error and discussion could be found at WebAssembly with Rust problem compiling wasm.

[thekingofcity]

Although the neon has an example of how to construct a class in JS, this passage suggests a way of doing so without prototypes or classes.

JavaScript Pop Quiz 6: Which Do Experienced JavaScript Developers Prefer—Prototypes or Classes?
You guessed it, that’s another trick question—experienced JavaScript developers tend to avoid both when they can.
...

I update the code in 678caf3 to be composition and the code should look modern now. ✨

[thekingofcity]

Every feature mentioned in this issue is implemented in the related issues. The first stage of Nodejs binding should be complete.

Say Hi to @pravega/pravega and its documentation. 🎉