add msrv check

.github/workflows/readme-checks.yml

@@ -0,0 +1,44 @@
+name: rust
+
+on:
+  push:
+    branches: [ "main" ]
+  workflow_dispatch: {}
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  check msrv:
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+    - uses: actions/checkout@v4
+    - name: find version mentioned in readme
+      id: readme-version
+      run: |
+        set -euo pipefail
+        pwd
+        mkdir -p target/debug
+        cargo build
+        readme_version="$(cat README.md | ./target/debug/mdq '# Development | P: "Requires rustc >=" ' | awk '{print $NF}')"
+        echo "result=$readme_version" >> "$GITHUB_OUTPUT"
+    - name: pull cargo-msrv from docker hub
+      run: docker pull foresterre/cargo-msrv
+    - name: find minimum supported rust version
+      id: run-msrv
+      run: |
+        set -euo pipefail
+        min_version="$(docker run --rm -t -v "$PWD/":/app/ foresterre/cargo-msrv find --no-log --output-format minimal | tr -d $'\r\n')"
+        echo "result=$min_version" >> "$GITHUB_OUTPUT"
+    - name: compare versions
+      run: |
+        echo "::notice title=cargo-msrv::$MSRV_VERSION"
+        echo "::notice title=README.md-msrv::$README_VERSION"
+        if [[ "$MSRV_VERSION" != "$README_VERSION" ]]; then
+          echo "::error title=msrv-mismatch::cargo-msrv was $MSRV_VERSION but README.md says rustc >= $README_VERSION"
+          exit 1
+        fi
+      env:
+        MSRV_VERSION: ${{ steps.run-msrv.outputs.result }}
+        README_VERSION: ${{ steps.readme-version.outputs.result }}

.github/workflows/rust.yml

@@ -27,6 +27,7 @@ jobs:
           echo "::error file=$file_path,title=git-status::<$status_code> $file_path"
         done <<<"$(git status --porcelain)"
         exit "$exit_code"
+
   check:
     runs-on: ubuntu-latest
     needs: build

README.md

@@ -42,6 +42,7 @@ Any of these will work:
 
 1. ```shell
    cargo install --git https://github.com/yshavit/mdq
+   ```
 2. ```shell
    brew install mdq
    ```
@@ -179,3 +180,15 @@ cat oncall.md | mdq ':-: * :-: 2024-01-15'
 |:----------:|:-----:|:---:|:---:|----:|
 | 2024-01-15 |       |     |  x  |     |
 ```
+
+# Development
+
+Requires rustc >= 1.20.0
+
+```bash
+cargo build
+```
+
+```bash
+cargo test
+```