Add script to easily update Spin formula for new releases

Signed-off-by: Kate Goldenring <[email protected]>

README.md

@@ -22,3 +22,15 @@ a pull request.
 ```sh
 brew test-bot --only-tap-syntax
 ```
+
+### Updating the Spin Formula for a New Release
+
+Run the [`bump-spin-formula.sh`](scripts/bump-spin-formula.sh) to update the
+formula to use the assets of a specific release (say `v2.4.0`):
+
+```sh
+./scripts/bump-spin-formula.sh v2.4.0
+```
+
+The script will update the version in the formula, get the checksums file from
+the specified release, and update the checksum for each architecture and OS.

scripts/bump-spin-formula.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+
+VERSION=$1
+FORMULA=${2:-Formula/Spin.rb}
+
+usage() {
+    echo "Usage: $0 <VERSION> [<FORMULA_PATH>]"
+    echo "Updates the Spin Formula for the specified release version"
+    echo "Example: $0 3.0.0"
+}
+
+if [ $# -ne 1 ]; then
+    usage
+    exit 1
+fi
+
+# Get the checksum file for the release
+wget -qO checksums.txt "https://github.com/fermyon/spin/releases/download/$VERSION/checksums-$VERSION.txt"
+
+# Update the formula version
+ERSION="${VERSION:1}"
+sed -i '' -e "s/version \"[^\"]*\"/version \"$ERSION\"/" $FORMULA
+
+# Update the sha256 checksums for each OS/Arch
+while read -r line; do
+    filename=$(echo "$line" | awk '{print $2}')
+    sha256=$(echo "$line" | awk '{print $1}')
+    os_arch="${filename:12}"
+    if grep -q "$os_arch" $FORMULA; then
+    sed -i '' -E "/url \".*$os_arch\"/ { n; s/sha256 \"[^\"]*\"/sha256 \"$sha256\"/; }" $FORMULA
+    fi
+
+done < checksums.txt
+
+rm checksums.txt
+
+echo "Formula updated to version $VERSION with new checksums."