added mac and hardhat support

trimport_hardhat.sh

@@ -0,0 +1,43 @@
+#!/bin/sh
+# This script tries to remove imports one by one while making sure that the
+# project can still be compiled, so that the minimum number of imports is used.
+# This approach is really inefficient, but good enough given that it can just
+# be run once in a while to unclutter imports.
+set -e
+set -u
+
+compile(){
+  echo Compiling...
+  hardhat compile >/dev/null 2>&1
+}
+
+echo "This script will run on the following files:"
+find 'contracts' -iname '*.sol'
+echo "Continue? [y/N]"
+
+read -r answer
+if [ "$answer" != "y" ]; then
+  exit 2
+fi
+
+
+echo "Compiling once with original files as a sanity check"
+compile || exit 3
+
+tmp="$(mktemp)"
+
+find 'contracts' -type f -iname '*.sol' |\
+while read -r f ; do
+  grep -n '^ *import' "$f" | cut -d':' -f1 |\
+    while read -r line; do
+      cp "$f" "$tmp"
+      # mac shell bsd needs the option .bak
+      # https://stackoverflow.com/a/4247333/10832249
+      sed -i .bak "$line"'s/.*//' "$f"
+      compile || cp "$tmp" "$f"
+    done
+done
+
+echo "remove .bak files created in contracts folder"
+find contracts -name "*.bak" -delete
+exit 0