Automate backport public API inventory in APIs.md

.github/scripts/generate-public-api-list.sh

@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+mode="--write"
+if [[ "${1:-}" == "--check" ]]; then
+  mode="--check"
+fi
+
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd -P)"
+repo_root="$(cd "${script_dir}/../.." && pwd -P)"
+
+if [[ ! -f "${repo_root}/Package.swift" ]]; then
+  echo "error: Could not resolve repository root from script location." >&2
+  exit 1
+fi
+symbol_graph_dir="${repo_root}/.build/public-api-symbol-graphs"
+apis_path="${repo_root}/APIs.md"
+cd "${repo_root}"
+
+rm -rf "${symbol_graph_dir}"
+mkdir -p "${symbol_graph_dir}"
+
+if ! command -v swift >/dev/null 2>&1; then
+  echo "error: Swift is required to generate the public API list." >&2
+  exit 1
+fi
+
+help_text="$(swift package dump-symbol-graph -help 2>&1 || true)"
+
+dump_command=(swift package dump-symbol-graph --minimum-access-level public)
+
+if grep -q -- "--target" <<< "${help_text}"; then
+  dump_command+=(--target SwiftUIBackports)
+fi
+
+if grep -q -- "--output-path" <<< "${help_text}"; then
+  dump_command+=(--output-path "${symbol_graph_dir}")
+  "${dump_command[@]}"
+else
+  before_list="$(mktemp)"
+  after_list="$(mktemp)"
+  new_list="$(mktemp)"
+  cleanup() {
+    rm -f "${before_list}" "${after_list}" "${new_list}"
+  }
+  trap cleanup EXIT
+
+  find "${repo_root}/.build" -type f -name "*.symbols.json" 2>/dev/null | sort > "${before_list}" || true
+
+  "${dump_command[@]}"
+
+  find "${repo_root}/.build" -type f -name "*.symbols.json" 2>/dev/null | sort > "${after_list}" || true
+
+  comm -13 "${before_list}" "${after_list}" > "${new_list}" || true
+
+  if [[ -s "${new_list}" ]]; then
+    while IFS= read -r symbol_file; do
+      cp "${symbol_file}" "${symbol_graph_dir}/"
+    done < "${new_list}"
+  elif [[ -s "${after_list}" ]]; then
+    while IFS= read -r symbol_file; do
+      cp "${symbol_file}" "${symbol_graph_dir}/"
+    done < "${after_list}"
+  else
+    echo "error: dump-symbol-graph did not produce any .symbols.json files" >&2
+    exit 1
+  fi
+fi
+
+swift "${repo_root}/.github/scripts/generate_public_api_list.swift" \
+  --symbol-graphs-dir "${symbol_graph_dir}" \
+  --apis-file "${apis_path}" \
+  "${mode}"