WIP: Break out features

[wkatsak]

Hello,

I've created this PR to get comments on my strategy for this solution. If this is satisfactory, I'll clean everything up.

I'm working on a project targeting wasm in the browser (via wasm-pack / wasm-bindgen). For this use case, I obviously can't have any of the ZMQ code being included. I also don't particularly need the signing code (I am using cylinder instead).

The main idea is to keep the default behavior as it functioned previously, but also to allow bringing in the SDK using whatever subset of the features you need.

Thanks in advance for any feedback.

Sincerely,
Bill

[vaporos]

Looks fine to me.

[vaporos]

The best way to test this is going to be installing just and then running "just lint" and "just test". By modifying justfile, you can make it so that it tests any combination of features that you want to make sure work (i.e. if you want only one feature on, you could lint/test/build that way). The CI just runs "just build", "just lint", "just test".

[wkatsak]

The linter is not breaking because of anything I changed. The blocking error is as follows:

    Checking sawtooth-sdk v0.5.3 (/Volumes/Storage/taekion/sawtooth-sdk-rust)
error: unused `#[macro_use]` import
  --> src/lib.rs:18:1
   |
18 | #[macro_use]
   | ^^^^^^^^^^^^
   |
   = note: `-D unused-imports` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(unused_imports)]`

[vaporos]

The error occurs because we lint with "cargo clippy --manifest-path=./Cargo.toml --no-default-features -- -D warnings" to make sure things aren't broken with all features off, and with your changes, all use of logging code is behind features.

Because logging only happens in the zmq code, you can just add this to fix it:

diff --git a/src/lib.rs b/src/lib.rs
index 6ee492d1..a865d868 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -15,6 +15,7 @@
  * ------------------------------------------------------------------------------
  */

+#[cfg(feature = "zmq")]
 #[macro_use]
 extern crate log;

[wkatsak]

I made the change suggested by @vaporos and added a better commit message. The tests look like they pass now.