ci: Add CI for automatic release

.Rbuildignore

@@ -21,3 +21,7 @@
 ^dev$
 ^\.posit$
 ^temp$
+^CHANGELOG\.md$
+^version\.txt$
+^release-please-config\.json$
+^\.release-please-manifest\.json$

.github/workflows/R-CMD-check.yaml

@@ -8,6 +8,9 @@ on:
   pull_request:
     branches: [main]
 
+permissions:
+  contents: read
+
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: ${{ github.event_name == 'pull_request' }}
@@ -90,3 +93,32 @@ jobs:
           error-on: '"error"'
           args: 'c("--no-manual", "--ignore-vignettes", "--as-cran")'
           build_args: 'c("--no-manual", "--no-build-vignettes")'
+
+  version-sync:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: Verify release-please can still bump DESCRIPTION
+        shell: bash
+        run: |
+          set -euo pipefail
+
+          # write.dcf() and desc::desc_set() silently drop comment lines, which
+          # would stop release-please bumping Version with no error anywhere.
+          for marker in '# x-release-please-start-version' '# x-release-please-end'; do
+            if ! grep -qxF "$marker" DESCRIPTION; then
+              echo "::error file=DESCRIPTION::Missing '$marker'. release-please can no longer update Version; restore the marker."
+              exit 1
+            fi
+          done
+
+          desc_version="$(sed -n 's/^Version:[[:space:]]*//p' DESCRIPTION | tr -d '[:space:]')"
+          manifest_version="$(jq -r '."."' .release-please-manifest.json)"
+
+          if [ "$desc_version" != "$manifest_version" ]; then
+            echo "::error::DESCRIPTION Version ($desc_version) != .release-please-manifest.json ($manifest_version). These must match; release-please updates both together."
+            exit 1
+          fi
+
+          echo "OK: markers present, version $desc_version in sync."

.github/workflows/release-please.yaml

@@ -0,0 +1,24 @@
+# Maintains a rolling "release PR" on main. Merging it tags the version and
+# publishes a GitHub Release, which is what r-universe tracks ("branch": "*release").
+name: Release Please
+
+on:
+    push:
+        branches: [main]
+
+permissions:
+    contents: write
+    pull-requests: write
+
+concurrency:
+    group: ${{ github.workflow }}-${{ github.ref }}
+    cancel-in-progress: false
+
+jobs:
+    release-please:
+        runs-on: ubuntu-latest
+        steps:
+            - uses: googleapis/release-please-action@v4
+              with:
+                  config-file: release-please-config.json
+                  manifest-file: .release-please-manifest.json

.release-please-manifest.json

@@ -0,0 +1,3 @@
+{
+    ".": "3.2.4"
+}

DESCRIPTION

@@ -1,7 +1,9 @@
 Type: Package
 Package: Pmetrics
 Title: Pmetrics for Population Modeling and Simulation
+# x-release-please-start-version
 Version: 3.2.4
+# x-release-please-end
 Authors@R: c(
     person("Michael", "Neely", , "mneely@usc.edu", role = c("aut", "cre")),
     person("Julián", "Otálvaro", , "juliandavid347@gmail.com", role = "aut"),

release-please-config.json

@@ -0,0 +1,58 @@
+{
+    "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
+    "packages": {
+        ".": {
+            "release-type": "simple",
+            "package-name": "Pmetrics",
+            "changelog-path": "CHANGELOG.md",
+            "extra-files": [
+                {
+                    "type": "generic",
+                    "path": "DESCRIPTION"
+                }
+            ],
+            "include-component-in-tag": false,
+            "include-v-in-tag": true,
+            "changelog-sections": [
+                {
+                    "type": "feat",
+                    "section": "Features"
+                },
+                {
+                    "type": "fix",
+                    "section": "Bug Fixes"
+                },
+                {
+                    "type": "perf",
+                    "section": "Performance"
+                },
+                {
+                    "type": "deps",
+                    "section": "Dependencies"
+                },
+                {
+                    "type": "chore",
+                    "section": "Maintenance"
+                },
+                {
+                    "type": "docs",
+                    "section": "Documentation"
+                },
+                {
+                    "type": "refactor",
+                    "section": "Refactoring"
+                },
+                {
+                    "type": "ci",
+                    "section": "Continuous Integration",
+                    "hidden": true
+                },
+                {
+                    "type": "test",
+                    "section": "Tests",
+                    "hidden": true
+                }
+            ]
+        }
+    }
+}