add tests for zstd compression

tests/local.mk

@@ -27,6 +27,7 @@ nix_tests = \
   signing.sh \
   shell.sh \
   brotli.sh \
+  zstd.sh \
   pure-eval.sh \
   check.sh \
   plugins.sh \

tests/zstd.sh

@@ -0,0 +1,28 @@
+source common.sh
+
+clearStore
+clearCache
+
+cacheURI="file://$cacheDir?compression=zstd"
+
+outPath=$(nix-build dependencies.nix --no-out-link)
+
+nix copy --to $cacheURI $outPath
+
+HASH=$(nix hash path $outPath)
+
+clearStore
+clearCacheCache
+
+nix copy --from $cacheURI $outPath --no-check-sigs
+
+if ls $cacheDir/nar/*.zst &> /dev/null; then
+    echo "files do exist"
+else
+    echo "nars do not exist"
+    exit 1
+fi
+
+HASH2=$(nix hash path $outPath)
+
+[[ $HASH = $HASH2 ]]