build: scripts/sync-upstream.sh for upstream merges

Author: Broccolito

scripts/sync-upstream.sh

@@ -0,0 +1,74 @@
+#!/usr/bin/env bash
+# Sync engine/ with a newer upstream CodeGraph release.
+#
+# Usage: scripts/sync-upstream.sh <upstream-tag>
+#
+# Workflow:
+#   1. Clone upstream at the target tag into a tmp dir.
+#   2. rsync into engine/ (preserving our patches isn't fully automatic —
+#      conflicts on files we patched must be resolved by hand in the resulting
+#      diff).
+#   3. Update engine/UPSTREAM.md with the new tag/SHA.
+#   4. Leaves the working tree dirty so the user can review + commit.
+
+set -euo pipefail
+
+if [[ $# -ne 1 ]]; then
+  echo "usage: $0 <upstream-tag>"
+  exit 64
+fi
+
+TAG="$1"
+cd "$(dirname "$0")/.."
+REPO_ROOT="$(pwd)"
+
+TMP="$(mktemp -d -t cga-sync-XXXXXX)"
+trap "rm -rf '$TMP'" EXIT
+
+echo "[1/4] Cloning upstream at $TAG..."
+gh repo clone colbymchenry/codegraph "$TMP/upstream" -- --depth 1 --branch "$TAG"
+
+SHA="$(cd "$TMP/upstream" && git rev-parse HEAD)"
+
+echo "[2/4] Syncing into engine/..."
+rsync -a --delete \
+  --exclude='.git' \
+  --exclude='.github' \
+  --exclude='node_modules' \
+  --exclude='release' \
+  --exclude='UPSTREAM.md' \
+  --exclude='PATCHES.md' \
+  "$TMP/upstream/" engine/
+
+echo "[3/4] Updating engine/UPSTREAM.md..."
+DATE="$(date +%Y-%m-%d)"
+cat > engine/UPSTREAM.md <<EOF
+# Upstream Provenance
+
+This directory is a flat copy of [CodeGraph](https://github.com/colbymchenry/codegraph)
+at a pinned commit. We do not preserve upstream's git history here.
+
+| Field | Value |
+| --- | --- |
+| Upstream repo | https://github.com/colbymchenry/codegraph |
+| Vendored tag | $TAG |
+| Vendored commit SHA | $SHA |
+| Vendored on | $DATE |
+
+## Updating
+
+Run \`scripts/sync-upstream.sh <new-tag>\`. It fetches upstream at the target
+tag, syncs into \`engine/\`, and updates this file. Re-apply our patches as
+needed (see \`engine/PATCHES.md\`).
+
+## What we change
+
+See \`engine/PATCHES.md\` for the list of modifications layered on top of this
+upstream snapshot.
+EOF
+
+echo "[4/4] Done. Review with:"
+echo "    git status engine/"
+echo "    git diff engine/PATCHES.md"
+echo
+echo "Then re-apply patches per engine/PATCHES.md, run tests, and commit."