#!/usr/bin/env bash
# Shared helper functions for MCP handlers.
# Reduces duplication of error formatting and response building across handlers.
set -euo pipefail
# Normalize error codes: convert 0, empty, or "null" to default JSON-RPC internal error.
# Usage: code="$(mcp_handler_normalize_error_code "${code}" "${default:-32603}")"
mcp_handler_normalize_error_code() {
local code="${1:-}"
local default="${2:--32603}"
case "${code}" in
0 | "" | "null") printf '%s' "${default}" ;;
*) printf '%s' "${code}" ;;
esac
}
# Format a JSON-RPC 2.0 error response.
# Usage: mcp_handler_error_response "${id}" "${code}" "${quoted_message}" ["${data}"]
# Note: message must already be JSON-quoted (use mcp_json_quote_text).
mcp_handler_error_response() {
local id="$1"
local code="$2"
local message="$3"
local data="${4:-}"
if [ -n "${data}" ] && [ "${data}" != "null" ]; then
printf '{"jsonrpc":"2.0","id":%s,"error":{"code":%s,"message":%s,"data":%s}}' \
"${id}" "${code}" "${message}" "${data}"
else
printf '{"jsonrpc":"2.0","id":%s,"error":{"code":%s,"message":%s}}' \
"${id}" "${code}" "${message}"
fi
}
# Format a JSON-RPC 2.0 success response.
# Usage: mcp_handler_success_response "${id}" "${result_json}"
mcp_handler_success_response() {
local id="$1"
local result="$2"
printf '{"jsonrpc":"2.0","id":%s,"result":%s}' "${id}" "${result}"
}
