Prisma MCP Server

/** * Query parameterization logic for Prisma query insights. * * This module handles the conversion of Prisma queries into parameterized shapes * where user data values are replaced with placeholder markers. * * Design principle: when in doubt, parameterize. We're building query shapes * for observability, not actual query parameterization for the query compiler. */ /** * Placeholder object used to replace parameterized values in query shapes. */ export const PARAM_PLACEHOLDER = { $type: 'Param' } /** * Keys that represent nested relation operations within data contexts. * These switch back from data context to default context. */ const RELATION_OPERATION_KEYS = new Set([ 'connect', 'connectOrCreate', 'disconnect', 'set', 'create', 'createMany', 'update', 'updateMany', 'upsert', 'delete', 'deleteMany', ]) /** * Keys that switch from data context back to default context. */ const STRUCTURAL_KEYS_IN_DATA = new Set([ 'where', 'select', 'include', 'omit', '_count', '_sum', '_avg', '_min', '_max', ]) /** * Keys whose primitive values are structural (not user data). */ const STRUCTURAL_VALUE_KEYS = new Set(['take', 'skip', 'sort', 'nulls', 'mode', 'relationLoadStrategy', 'distinct']) type Context = 'default' | 'selection' | 'orderBy' | 'data' function isTaggedValue(value: unknown): value is { $type: string; value: unknown } { return ( typeof value === 'object' && value !== null && '$type' in value && typeof (value as { $type: unknown }).$type === 'string' ) } function isSelectionMarker(key: string): boolean { return key === '$scalars' || key === '$composites' } function isSortDirection(value: string): boolean { return value === 'asc' || value === 'desc' } /** * Get the context for a child key's value based on the key name and parent context. */ function getChildContext(key: string, parentContext: Context): Context { // These keys always introduce their specific context if (key === 'arguments') return 'default' if (key === 'selection') return 'selection' if (key === 'orderBy') return 'orderBy' if (key === 'data') return 'data' // In data context, certain keys escape back to default if (parentContext === 'data') { if (RELATION_OPERATION_KEYS.has(key) || STRUCTURAL_KEYS_IN_DATA.has(key)) { return 'default' } } // Otherwise inherit parent context return parentContext } /** * Recursively parameterize a value based on its context. */ function parameterize(value: unknown, context: Context, key?: string): unknown { if (value === null || value === undefined) { return value } if (isTaggedValue(value)) { return value.$type === 'FieldRef' ? value : PARAM_PLACEHOLDER } if (Array.isArray(value)) { return value.map((item) => parameterize(item, context, key)) } if (typeof value === 'object') { return parameterizeObject(value as Record<string, unknown>, context) } if (key && STRUCTURAL_VALUE_KEYS.has(key)) { return value } // In selection context, booleans indicate field selection if (context === 'selection' && typeof value === 'boolean') { return value } if (context === 'orderBy' && typeof value === 'string' && isSortDirection(value)) { return value } return PARAM_PLACEHOLDER } /** * Parameterize an object by processing each key-value pair. */ function parameterizeObject(obj: Record<string, unknown>, context: Context): Record<string, unknown> { const result: Record<string, unknown> = {} for (const [key, value] of Object.entries(obj)) { if (isSelectionMarker(key)) { result[key] = value continue } const childContext = getChildContext(key, context) result[key] = parameterize(value, childContext, key) } return result } /** * Parameterizes a query object, replacing all user data values with placeholders. */ export function parameterizeQuery(query: unknown): unknown { return parameterize(query, 'default') }