Add GitHub Actions workflow to test R builds

test/get_platforms.py

@@ -0,0 +1,31 @@
+import argparse
+import json
+import subprocess
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Print R-builds platforms as JSON.")
+    parser.add_argument(
+        'platforms',
+        type=str,
+        nargs='?',
+        default='all',
+        help='Comma-separated list of platforms. Specify "all" to use all platforms (the default).'
+    )
+    args = parser.parse_args()
+    platforms = _get_platforms(which=args.platforms)
+    print(json.dumps(platforms))
+
+
+def _get_platforms(which='all'):
+    supported_platforms = subprocess.check_output(['make', 'print-platforms'], text=True)
+    supported_platforms = supported_platforms.split()
+    if which == 'all':
+        return supported_platforms
+    platforms = which.split(',')
+    platforms = [p for p in platforms if p in supported_platforms]
+    return platforms
+
+
+if __name__ == '__main__':
+    main()

test/get_r_versions.py

@@ -0,0 +1,67 @@
+import argparse
+import json
+import re
+import urllib.request
+
+VERSIONS_URL = 'https://cdn.rstudio.com/r/versions.json'
+
+# Minimum R version for "all"
+MIN_ALL_VERSION = '3.1.0'
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Print R-builds R versions as JSON.")
+    parser.add_argument(
+        'versions',
+        type=str,
+        nargs='?',
+        default='last-5',
+        help="""Comma-separated list of R versions. Specify "last-N" to use the
+            last N minor R versions, or "all" to use all minor R versions since R 3.1.
+            Defaults to "last-5".
+            """
+    )
+    args = parser.parse_args()
+    versions = _get_versions(which=args.versions)
+    print(json.dumps(versions))
+
+
+def _get_versions(which='all'):
+    supported_versions = sorted(_get_supported_versions(), reverse=True)
+    
+    last_n_versions = None
+    if which.startswith('last-'):
+        last_n_versions = int(which.replace('last-', ''))
+    elif which != 'all':
+        versions = which.split(',')
+        versions = [v for v in versions if v in supported_versions]
+        return versions
+
+    versions = {}
+    for ver in supported_versions:
+        # Skip unreleased versions (e.g., devel, next)
+        if not re.match(r'[\d.]', ver):
+            continue
+        if ver < MIN_ALL_VERSION:
+            continue
+        minor_ver = tuple(ver.split('.')[0:2])
+        if minor_ver not in versions:
+            versions[minor_ver] = ver
+    versions = sorted(list(versions.values()), reverse=True)
+
+    if last_n_versions:
+        return versions[0:last_n_versions]
+
+    return versions
+
+
+def _get_supported_versions():
+    request = urllib.request.Request(VERSIONS_URL)
+    response = urllib.request.urlopen(request)
+    data = response.read()
+    result = json.loads(data)
+    return result['r_versions']
+
+
+if __name__ == '__main__':
+    main()