jsonb-plugin.ts

import type { KyselyPlugin, PluginTransformQueryArgs, PluginTransformResultArgs, QueryResult, RootOperationNode, UnknownRow } from 'kysely';

function toJsonb(func: unknown) {
    if (typeof func !== 'string') {
        throw new Error('Invalid function');
    }

    switch (func) {
        case 'json_agg': return 'jsonb_agg';
        case 'to_json': return 'to_jsonb';
        default: return func;
    }
}

function transformFuncKey(obj: unknown): unknown {
    if (typeof obj !== 'object' || obj === null) {
        return obj;
    }

    if (Array.isArray(obj)) {
        return obj.map(transformFuncKey);
    }

    return Object.fromEntries(
        Object.entries(obj as Record<string, unknown>).map(([key, value]) => {
            if (key === 'func' && typeof value === 'string') {
                // eslint-disable-next-line no-param-reassign
                value = toJsonb(value);
            }
            else {
                // eslint-disable-next-line no-param-reassign
                value = transformFuncKey(value);
            }
            return [key, value];
        })
    );
}

export class JSONBPlugin implements KyselyPlugin {
    public transformQuery(args: PluginTransformQueryArgs): RootOperationNode {
        if (args.node.kind !== 'SelectQueryNode') {
            return args.node;
        }

        const res = transformFuncKey(args.node) as RootOperationNode;
        console.log(JSON.stringify(res, null, 4));
        return transformFuncKey(args.node) as RootOperationNode;
    }

    // eslint-disable-next-line @typescript-eslint/require-await
    public async transformResult(args: PluginTransformResultArgs): Promise<QueryResult<UnknownRow>> {
        // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
        if (args.result.rows && Array.isArray(args.result.rows)) {
            return {
                ...args.result,
                rows: args.result.rows,
            };
        }

        return args.result;
    }
}