adjust lint workflow

.github/workflows/lint.yml

@@ -2,8 +2,13 @@ name: lint
 
 on:
   push:
-    branches: [main, master, 0.4.x]
+    branches: [main, 0.4.x]
   pull_request:
+    paths:
+      - "**.rs"
+      - .github/**
+      - .ci/**
+      - Cargo.toml
 
 jobs:
   lint:
@@ -11,15 +16,9 @@ jobs:
 
     steps:
       - uses: actions/checkout@v2
-      - name: Install rust
-        uses: actions-rs/toolchain@v1
-        with:
-          toolchain: stable
-          override: true
+      - uses: dtolnay/rust-toolchain@stable
       - uses: Swatinem/rust-cache@v1
-      - name: Lint
-        run: bash ci/lint.sh
-      - name: Run ShellCheck
-        uses: ludeeus/action-shellcheck@0.3.0
-        with:
-          check_together: "y"
+      - run: cargo fmt -- --check --color=always
+      - run: cargo clippy --color=always -- -D warnings -A clippy::manual-non-exhaustive
+        env:
+          RUSTFLAGS: "-Dwarnings"

ci/lint.sh

@@ -1,15 +0,0 @@
-#!/usr/bin/env bash
-
-set -euo pipefail
-
-# shellcheck source=ci/_shlib.sh
-source "${BASH_SOURCE[0]%/*}/_shlib.sh"
-
-main() {
-    # rustflags are present because of: https://github.com/rust-lang/rust-clippy/issues/5749
-    runt env RUSTFLAGS="-Dwarnings" cargo clippy --color=always -- -D warnings -A clippy::manual-non-exhaustive
-    runt cargo fmt -- --check --color=always
-    runv git diff --exit-code -- README.md
-}
-
-main