build: move build complexity to justfile

Keep build and test logic as agnostic as possible to whatever CI task
runner is used (today that is Github Actions). Let the CI job focus on
performance, like caching artifacts and keep the build and test logic in
the forefront easy for developers to use.

With that goal in mind, the CI job has been refactored to a handful
of jobs which each call a `just` recipe. Consistent caching has been
added to each job which shows a nice improvement in speed for the
workflow, running in less than a minute. The justfile has been
refactored with the logic that previously lived in the CI yaml. This
makes it easier to maintain as well as run locally when developing. A
few un-used recipes have been cleaned up.

Lockfile complexity has been relegated to the _test-msrv recipe. This
recipe checks that there is at least one set of dependencies which
satisfy the msrv requirements. The check no longer depends on the
checked in lockfile which doesn't matter much since consumers create
their own.

A rust-toolchain.toml file was added as a gently nudge for contributers
to stay on a recent version of "stable", that way we can use some of the
newer features like the v3 resolver and see less of "works on my
machine". CI will most likely not use the file however, since it usually
needs to test more complex things like MSRV.

Author: nyonson

.cargo/config.toml

@@ -0,0 +1,3 @@
+# Opt in to the v3 MSRV-aware resolver.
+[resolver]
+incompatible-rust-versions = "fallback"

.github/workflows/ci.yml

@@ -1,69 +1,70 @@
-name: Build & Test
+# A few guiding principles.
+# 
+# * Always use actions-rust-lang/setup-rust-toolchain for its built-in caching.
+# * Complexity lives in the justfile, this runner is as light as possible.
+ 
+name: CI
 
+# Run on direct commits to master, including merges, and any pull requests against master.
 on:
   push:
     branches:
       - master
   pull_request:
+    branches:
+      - master
 
 jobs:
-  build:
+  # Quick canary of code as well as potential issues with upcoming toolchains.
+  check:
     strategy:
       matrix:
-        platform: [ubuntu-latest, macos-latest, windows-latest]
         toolchain: [stable, beta, nightly]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: extractions/setup-just@v3
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+        with:
+          toolchain: ${{ matrix.toolchain }}
+          components: clippy,rustfmt
+      - run: just check
+  # Build and test the code across platforms.
+  test:
+    strategy:
+      matrix:
+        platform: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.platform }}
     steps:
-      - uses: actions/checkout@v3
-      - name: Update Toolchain
-        run: |
-          rustup default ${{ matrix.toolchain }}
-          rustup component add --toolchain ${{ matrix.toolchain }} rustfmt
-          rustup component add --toolchain ${{ matrix.toolchain }} clippy
-          rustup update ${{ matrix.toolchain }}
-      - name: Lint all targets
-        run: cargo clippy --all-targets
-      - name: Format
-        run: cargo fmt -- --check
-      - name: Build with defeault features
-        run: cargo build --verbose
-      - name: Check release build on Rust ${{ matrix.toolchain }}
-        run: cargo check --release --verbose --color always
-      - name: Unit test
-        run: cargo test --verbose --lib
-      - name: Doc test
-        run: cargo test --verbose --doc
-  # Check that library code can be compiled with MSRV (1.63.0).
+      - uses: actions/checkout@v4
+      - uses: extractions/setup-just@v3
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+      - run: just test unit
+  features:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: extractions/setup-just@v3
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+      - run: just test features
   msrv:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      # Modify build tools just for MSRV testing. This avoids us having
-      # to bump our MSRV just for tooling. Tooling doesn't effect consumers so not a risk.
-      - name: Prepare environment for MSRV toolchain
-        run: |
-          # Remove resolver = "3" line for MSRV compatibility. We use V3 to
-          # generate an MSRV-compliant lockfile, but this isn't necessary to
-          # check if library code is MSRV compliant. Any resolver can go
-          # and grab the versions specified in the committed lockfile.
-          #
-          # The V3 resolver is standard in rust 1.85.
-          sed -i '/resolver = "3"/d' Cargo.toml
-      - name: Install MSRV toolchain
-        run: |
-          rustup toolchain install 1.63.0
-          rustup default 1.63.0
-      - name: Build with MSRV compiler
-        run: cargo build --verbose
-  signet:
+      - uses: actions/checkout@v4
+      - uses: extractions/setup-just@v3
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+      - run: just test msrv
+  sync:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - name: Sync signet
-        run: cargo test --verbose signet_syncs
-  bitcoind:
+      - uses: actions/checkout@v4
+      - uses: extractions/setup-just@v3
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+      - run: just test sync
+  integration:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - name: Integration test
-        run: cargo test -- --test-threads 1 --skip signet_syncs --nocapture
+      - uses: actions/checkout@v4
+      - uses: extractions/setup-just@v3
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
+      - run: just test integration

.gitignore

@@ -1,3 +1,4 @@
+Cargo.lock
 /target
 /data
 /light_client_data