Split Release Notes in public Discord into chunks

.github/workflows/tag-release.yml

@@ -54,6 +54,8 @@ jobs:
           RELEASE_URL: ${{ github.event.release.html_url || github.event.inputs.release_url }}
           RELEASE_TAG: ${{ github.event.release.tag_name || github.event.inputs.release_tag }}
         run: |
+          set -euo pipefail
+
           # Construct the Discord message with the release title and body
           message="**SpacetimeDB ${RELEASE_TAG}**"
           message+=$'\n\n'
@@ -63,26 +65,46 @@ jobs:
           message+=$'\n\n'
           message+="${RELEASE_BODY}"
 
-          # Use jq to construct the JSON payload for the webhook
-          data="$(jq --null-input \
-            --arg content "$message" \
-            '.content=$content')"
+          # Send a single chunk to Discord, exiting on HTTP error.
+          post_chunk() {
+            local chunk="$1"
+            local data
+            data="$(jq --null-input --arg content "$chunk" \
+              '.content=$content | .allowed_mentions={"parse":["roles","users"]}')"
+            if [ "${{ github.event.inputs.dry_run }}" = "true" ]; then
+              echo "=== DRY RUN chunk ==="
+              echo "$data" | jq .
+            else
+              curl --fail-with-body -X POST \
+                -H 'Content-Type: application/json' \
+                -d "$data" \
+                "${DISCORD_WEBHOOK_URL}"
+            fi
+          }
+
+          # Split message into chunks of at most 2000 characters, breaking on newlines.
+          MAX=2000
+          current_chunk=""
+          while IFS= read -r line || [ -n "$line" ]; do
+            # +1 for the newline we append after each line
+            candidate="${current_chunk}${line}"$'\n'
+            if [ "${#candidate}" -gt "$MAX" ]; then
+              if [ -n "$current_chunk" ]; then
+                post_chunk "$current_chunk"
+                current_chunk=""
+              fi
+              # If a single line exceeds the limit, bail out loudly rather than silently truncating.
+              if [ "$((${#line} + 1))" -gt "$MAX" ]; then
+                echo "ERROR: A single line is longer than ${MAX} characters and cannot be posted to Discord." >&2
+                exit 1
+              fi
+              current_chunk="${line}"$'\n'
+            else
+              current_chunk="$candidate"
+            fi
+          done <<< "$message"
 
-          # Dry run: just print what would be sent
-          if [ "${{ github.event.inputs.dry_run }}" = "true" ]; then
-            echo "=== DRY RUN - Message that would be sent to Discord ==="
-            echo "JSON payload:"
-            echo "$data" | jq .
-            echo ""
-            echo "Formatted message preview:"
-            echo "$message"
-            echo ""
-            echo "=== End of dry run ==="
-          else
-            # Send the webhook
-            echo "Sending Discord notification..."
-            curl -X POST \
-              -H 'Content-Type: application/json' \
-              -d "$data" \
-              "${DISCORD_WEBHOOK_URL}"
+          # Post any remaining content
+          if [ -n "$current_chunk" ]; then
+            post_chunk "$current_chunk"
           fi