add util/release.sh script to automatically bump the rules_rust version

util/release.sh

@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+#
+# Usage: util/release.sh [version]
+#
+# where version (optional) is the new version of rules_rust.
+set -xeuo pipefail
+
+# Normalize working directory to root of repository.
+cd "$(dirname "${BASH_SOURCE[0]}")"/..
+
+# Read the old version.
+readonly OLD="$(cat version.bzl | grep VERSION | awk '{print $3}' | tr -d '"')"
+
+function new_from_old() {
+  local major=$(awk -F. '{print $1}' <<<"$OLD")
+  local minor=$(awk -F. '{print $2}' <<<"$OLD")
+  echo "$major.$((minor + 1)).0"
+}
+
+readonly NEW="${1:-$(new_from_old)}"
+
+# Update matching VERSION constants in version.bzl files.
+function version_pattern() {
+  local version_quoted="\"$1\""
+  echo "VERSION = $version_quoted"
+}
+
+grep -rl \
+  --include='version.bzl' \
+  "$(version_pattern $OLD)" \
+  | xargs sed -i "s/^$(version_pattern $OLD)$/$(version_pattern $NEW)/g"
+
+# Update matching bazel_dep(name = "rules_rust", version = ...) declarations.
+function bazel_dep_pattern() {
+  local version_quoted="\"$1\""
+  echo "bazel_dep(name = \"rules_rust\", version = $version_quoted)"
+}
+
+grep -rl \
+  --include='MODULE.bazel' --include='*.bzl' --include='*.md' \
+  "$(bazel_dep_pattern $OLD)" \
+  | xargs sed -i "s/^$(bazel_dep_pattern $OLD)$/$(bazel_dep_pattern $NEW)/"
+
+# Update module() declarations:
+# module(
+#     name = "rules_rust",
+#     version = "...",
+# )
+function update_module_version() {
+  local file=$1
+
+  local out="$(awk -v old=$OLD -v new=$NEW '
+  BEGIN {
+    VERSION_PATTERN = "version = \"" old "\"";
+    NAME_PATTERN = "name = \"rules_rust.*\"";
+    CLOSING_PAREN_PATTERN = "^)$";
+
+    inside_module = 0;
+    name_matches = 0;
+  }
+  /^module\($/ {
+    inside_module = 1;
+  }
+  inside_module {
+    if ($0 ~ NAME_PATTERN) {
+      name_matches = 1;
+    } else if ($0 ~ VERSION_PATTERN && name_matches) {
+      gsub(old, new);
+    } else if ($0 ~ CLOSING_PAREN_PATTERN) {
+      inside_module = 0;
+      name_matches = 0;
+    }
+  }
+  { print }
+  ' "$file")"
+  echo "$out" > "$file"
+}
+
+find . -name MODULE.bazel -print0 | while IFS= read -r -d $'\0' file; do
+  update_module_version "$file"
+done