Attempt to centralize MSRV definition

.github/workflows/rust-ci.yml

@@ -16,26 +16,29 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        # 1.85 is the MSRV for the crate
-        rust: ['nightly', 'beta', 'stable', '1.85']
+        rust: ['nightly', 'beta', 'stable', 'msrv']
 
     runs-on: ubuntu-latest
     steps:
       - name: Checkout source
         uses: actions/checkout@v3
 
-      - name: Install ${{matrix.rust}} toolchain
+      - name: Resolve version
+        id: resolve_version
+        run: echo "version=$(./scripts/resolve-toolchain-version.sh ${{matrix.rust}})" >> "${GITHUB_OUTPUT}"
+
+      - name: Install ${{ steps.resolve_version.outputs.version }} toolchain
         if: matrix.rust == 'nightly'
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: ${{matrix.rust}}
+          toolchain: ${{ steps.resolve_version.outputs.version }}
           components: miri rustfmt clippy
 
-      - name: Install ${{matrix.rust}} toolchain
+      - name: Install ${{ steps.resolve_version.outputs.version }} toolchain
         if: matrix.rust != 'nightly'
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: ${{matrix.rust}}
+          toolchain: ${{ steps.resolve_version.outputs.version }}
           components: rustfmt clippy
 
       - uses: taiki-e/install-action@cargo-binstall
@@ -51,4 +54,4 @@ jobs:
 
 
       - name: Run full test script
-        run: ./scripts/full-test.sh "${{matrix.rust}}"
+        run: ./scripts/full-test.sh "${{ steps.resolve_version.outputs.version }}"

scripts/resolve-toolchain-version.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+set -o errexit # make script exit when a command fails
+set -o nounset # make script exit when using undeclared variables
+set -o pipefail # make script exit when command fails in a pipe
+set -o xtrace # print a trace of all commands executed by script
+
+if [ "$#" -ne 1 ]; then
+    >&2 echo "Illegal number of parameters [$#]"
+    >&2 echo "usage: ${0} <toolchain>"
+    exit 1
+fi
+
+MAYBE_RESOLVED="${1}"
+
+if [[ "${MAYBE_RESOLVED}" == "msrv" ]]; then
+    MAYBE_RESOLVED="$(cargo metadata --no-deps --format-version 1 \
+        | jq -r '.packages | map(select(.name == "blart"))[0].rust_version')"
+fi
+
+echo "${MAYBE_RESOLVED}"