Add Github Actions CI jobs for testing, linting, formatting etc

.github/workflows/build-and-test.yml

@@ -0,0 +1,61 @@
+---
+name: Build and test
+on:
+  pull_request:
+  workflow_dispatch:
+
+env:
+  CARGO_TERM_COLOR: always
+  # TODO: Do not allow dead_code once crate is out of early prototyping stage
+  RUSTFLAGS: --deny warnings --allow dead_code
+
+jobs:
+  build-and-test:
+    strategy:
+      matrix:
+        # TODO: Add and make Windows work in CI also
+        os: [ubuntu-latest, macos-latest]
+        # Keep MSRV in sync with rust-version in Cargo.toml
+        rust: [stable, beta, nightly, 1.79.0]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: dtolnay/rust-toolchain@21dc36fb71dd22e3317045c0c31a3f4249868b17 # master at the time of writing this
+        with:
+          toolchain: ${{ matrix.rust }}
+
+      - name: Build
+        run: cargo --version && cargo build --all-targets --locked
+
+      - name: Test
+        run: cargo test --locked
+
+      # Make sure documentation builds without warnings (broken links etc)
+      - name: Generate documentation
+        if: matrix.rust == 'stable'
+        run: RUSTDOCFLAGS="--deny warnings" cargo doc
+
+  # Make sure the library builds with all dependencies downgraded to their
+  # oldest versions allowed by the semver spec. This ensures we have not
+  # under-specified any dependency
+  minimal-versions:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install stable Rust
+        uses: dtolnay/rust-toolchain@21dc36fb71dd22e3317045c0c31a3f4249868b17 # master at the time of writing this
+        with:
+          toolchain: stable
+
+      - name: Install nightly Rust
+        uses: dtolnay/rust-toolchain@21dc36fb71dd22e3317045c0c31a3f4249868b17 # master at the time of writing this
+        with:
+          toolchain: nightly
+
+      - name: Downgrade dependencies to minimal versions
+        run: cargo +nightly update -Z minimal-versions
+
+      - name: Compile with minimal versions
+        run: cargo +stable build --all-targets --locked

.github/workflows/cargo-audit.yml

@@ -0,0 +1,29 @@
+---
+name: Audit dependencies
+on:
+  pull_request:
+    paths:
+      - .github/workflows/cargo-audit.yml
+      - Cargo.toml
+      - Cargo.lock
+  schedule:
+    # At 06:20 UTC every day. Will create an issue if a CVE is found.
+    - cron: '20 6 * * *'
+  workflow_dispatch:
+
+jobs:
+  audit:
+    runs-on: ubuntu-latest
+    permissions:
+      issues: write
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions-rust-lang/audit@160ac8b6edd32f74656cabba9d1de3fc8339f676 # v1.2
+        name: Audit Rust Dependencies
+        with:
+          denyWarnings: true
+          # Ignored audit issues. This list should be kept short, and effort should be
+          # put into removing items from the list.
+          ignore:

.github/workflows/formatting.yml

@@ -0,0 +1,24 @@
+---
+name: Rust formatting
+on:
+  pull_request:
+    paths:
+      - .github/workflows/formatting.yml
+      - '**/*.rs'
+  workflow_dispatch:
+jobs:
+  check-formatting:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install stable Rust
+        uses: dtolnay/rust-toolchain@21dc36fb71dd22e3317045c0c31a3f4249868b17 # master at the time of writing this
+        with:
+          toolchain: stable
+          components: rustfmt
+
+      - name: Check formatting
+        run: |
+          rustfmt --version
+          cargo fmt -- --check

.github/workflows/git-commit-message-style.yml

@@ -0,0 +1,32 @@
+---
+name: Git - Check commit message style
+on:
+  push:
+  workflow_dispatch:
+
+jobs:
+  check-commit-message-style:
+    name: Check commit message style
+    runs-on: ubuntu-latest
+    steps:
+      # Make sure there are no whitespaces other than space, tab and newline in a commit message.
+      - name: Check for unicode whitespaces
+        uses: gsactions/commit-message-checker@16fa2d5de096ae0d35626443bcd24f1e756cafee #v2.0.0
+        with:
+          # Pattern matches strings not containing weird unicode whitespace/separator characters
+          # \P{Z} = All non-whitespace characters (the u-flag is needed to enable \P{Z})
+          # [ \t\n] = Allowed whitespace characters
+          pattern: '^(\P{Z}|[ \t\n])+$'
+          flags: 'u'
+          error: 'Detected unicode whitespace character in commit message.'
+          checkAllCommitMessages: 'true' # optional: this checks all commits associated with a pull request
+          accessToken: ${{ secrets.GITHUB_TOKEN }} # only required if checkAllCommitMessages is true
+
+      # Git commit messages should follow these guidelines: https://cbea.ms/git-commit/
+      - name: Check against guidelines
+        uses: mristin/opinionated-commit-message@f3b9cec249cabffbae7cd564542fd302cc576827 #v3.1.1
+        with:
+          # Commit messages are allowed to be subject only, no body
+          allow-one-liners: 'true'
+          # This action defaults to 50 char subjects, but 72 is fine.
+          max-subject-line-length: '72'

.github/workflows/linting.yml

@@ -0,0 +1,28 @@
+---
+name: Rust linting
+on:
+  pull_request:
+    paths:
+      - .github/workflows/linting.yml
+      - '**/*.rs'
+      - Cargo.toml
+      - Cargo.lock
+  workflow_dispatch:
+jobs:
+  clippy-linting:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+
+      - name: Install stable Rust
+        uses: dtolnay/rust-toolchain@21dc36fb71dd22e3317045c0c31a3f4249868b17 # master at the time of writing this
+        with:
+          toolchain: stable
+          components: clippy
+
+      - name: Clippy check
+        env:
+          # TODO: Do not allow dead_code once crate is out of early prototyping stage
+          RUSTFLAGS: --deny warnings --allow dead_code
+        run: cargo clippy --locked --all-targets

Cargo.toml

@@ -28,4 +28,4 @@ toml = "0.8.14"
 serde = { version = "1.0.203", features = ["derive"] }
 
 [dev-dependencies]
-trycmd = "0.15.4"
+trycmd = "0.15.5"

src/config.rs

@@ -53,7 +53,7 @@ fn unicode_notation_to_char(unicode_notation: &str) -> Result<char, InvalidChara
     let parse = |unicode_notation: &str| -> Option<char> {
         let hex_str_number = unicode_notation.strip_prefix("U+")?;
         let int_number = u32::from_str_radix(hex_str_number, 16).ok()?;
-        Some(char::from_u32(int_number)?)
+        char::from_u32(int_number)
     };
     parse(unicode_notation).ok_or_else(|| InvalidCharacterType(unicode_notation.to_owned()))
 }
@@ -126,7 +126,7 @@ mod tests {
     #[should_panic]
     fn invalid_language() {
         static INVALID_LANGUAGE: &str = "[language.nonon]";
-        let config: Config = toml::from_str(INVALID_LANGUAGE).unwrap();
+        let _config: Config = toml::from_str(INVALID_LANGUAGE).unwrap();
     }
 
     #[test]