Update CI

.github/dependabot.yml

@@ -0,0 +1,14 @@
+version: 2
+updates:
+- package-ecosystem: github-actions
+  directory: "/"
+  schedule:
+    interval: daily
+    timezone: Etc/UTC
+  open-pull-requests-limit: 10
+  reviewers:
+  - str4d
+  assignees:
+  - str4d
+  labels:
+  - "A-CI"

.github/workflows/ci.yml

@@ -3,25 +3,6 @@ name: CI checks
 on: [push, pull_request]
 
 jobs:
-  lint:
-    name: Lint
-    runs-on: ubuntu-latest
-
-    steps:
-      - uses: actions/checkout@v1
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: 1.56.0
-          override: true
-
-      # Ensure all code has been formatted with rustfmt
-      - run: rustup component add rustfmt
-      - name: Check formatting
-        uses: actions-rs/cargo@v1
-        with:
-          command: fmt
-          args: -- --check --color always
-
   test:
     name: Test on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
@@ -30,25 +11,9 @@ jobs:
         os: [ubuntu-latest, windows-latest, macOS-latest]
 
     steps:
-      - uses: actions/checkout@v1
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: 1.56.0
-          override: true
-      - name: cargo fetch
-        uses: actions-rs/cargo@v1
-        with:
-          command: fetch
-      - name: Build tests
-        uses: actions-rs/cargo@v1
-        with:
-          command: build
-          args: --verbose --release --tests --features experimental,zeroize
+      - uses: actions/checkout@v3
       - name: Run tests
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --verbose --release --features experimental,zeroize
+        run: cargo test --verbose --release --features experimental,zeroize
 
   no-std:
     name: Check no-std target ${{ matrix.target }}
@@ -61,41 +26,41 @@ jobs:
           - wasm32-wasi
 
     steps:
-      - uses: actions/checkout@v1
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: 1.56.0
-          override: true
+      - uses: actions/checkout@v3
       - run: rustup target add ${{ matrix.target }}
-      - name: cargo fetch
-        uses: actions-rs/cargo@v1
-        with:
-          command: fetch
+      - run: cargo fetch
       - name: Build
-        uses: actions-rs/cargo@v1
-        with:
-          command: build
-          args: --verbose --target ${{ matrix.target }} --no-default-features --features groups,pairings
+        run: >
+          cargo build
+          --verbose
+          --target ${{ matrix.target }}
+          --no-default-features
+          --features groups,pairings
 
-  doc-links:
-    name: Nightly lint
+  bitrot:
+    name: Bitrot check
     runs-on: ubuntu-latest
-
     steps:
-      - uses: actions/checkout@v1
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: nightly
-          override: true
-      - name: cargo fetch
-        uses: actions-rs/cargo@v1
-        with:
-          command: fetch
+      - uses: actions/checkout@v3
+      # Build benchmarks and all-features to prevent bitrot
+      - name: Build benchmarks
+        run: cargo build --benches --examples --all-features
 
-      # Ensure intra-documentation links all resolve correctly
-      # Requires #![deny(intra_doc_link_resolution_failure)] in crate.
+  doc-links:
+    name: Intra-doc links
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - run: cargo fetch
+      # Requires #![deny(rustdoc::broken_intra_doc_links)] in crate.
       - name: Check intra-doc links
-        uses: actions-rs/cargo@v1
-        with:
-          command: doc
-          args: --document-private-items
+        run: cargo doc --document-private-items
+
+  fmt:
+    name: Rustfmt
+    timeout-minutes: 30
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Check formatting
+        run: cargo fmt --all -- --check

.github/workflows/lints-beta.yml

@@ -0,0 +1,24 @@
+name: Beta lints
+
+# These lints are only informative, so we only run them directly on branches
+# and not trial-merges of PRs, to reduce noise.
+on: push
+
+jobs:
+  clippy-beta:
+    name: Clippy (beta)
+    timeout-minutes: 30
+    runs-on: ubuntu-latest
+    continue-on-error: true
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dtolnay/rust-toolchain@beta
+        id: toolchain
+      - run: rustup override set ${{steps.toolchain.outputs.name}}
+      - name: Run Clippy (beta)
+        uses: actions-rs/clippy-check@v1
+        continue-on-error: true
+        with:
+          name: Clippy (beta)
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --all-features --all-targets -- -W clippy::all

.github/workflows/lints-stable.yml

@@ -0,0 +1,18 @@
+name: Stable lints
+
+# We only run these lints on trial-merges of PRs to reduce noise.
+on: pull_request
+
+jobs:
+  clippy:
+    name: Clippy (MSRV)
+    timeout-minutes: 30
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Run clippy
+        uses: actions-rs/clippy-check@v1
+        with:
+          name: Clippy (MSRV)
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --all-features --all-targets -- -D warnings

Cargo.toml

@@ -16,6 +16,7 @@ edition = "2021"
 rustdoc-args = [ "--html-in-header", "katex-header.html" ]
 
 [dev-dependencies]
+csv = ">= 1.0, < 1.2" # csv 1.2 has MSRV 1.60
 criterion = "0.3"
 hex = "0.4"
 rand_xorshift = "0.3"

rust-toolchain.toml

@@ -0,0 +1,3 @@
+[toolchain]
+channel = "1.56.0"
+components = [ "clippy", "rustfmt" ]

src/hash_to_curve/map_scalar.rs

@@ -10,7 +10,7 @@ impl HashToField for Scalar {
 
     fn from_okm(okm: &GenericArray<u8, U48>) -> Scalar {
         let mut bs = [0u8; 64];
-        bs[16..].copy_from_slice(&okm);
+        bs[16..].copy_from_slice(okm);
         bs.reverse(); // into little endian
         Scalar::from_bytes_wide(&bs)
     }