paseo/packages/cli/src/output/json.ts

/**
 * JSON renderer for CLI output.
 *
 * Renders structured data as formatted JSON for machine consumption.
 */

import type { AnyCommandResult, OutputOptions } from "./types.js";

/** Render command result as JSON */
export function renderJson<T>(result: AnyCommandResult<T>, _options: OutputOptions): string {
  const { schema } = result;

  // Apply custom serializer if provided
  if (schema.serialize) {
    if (result.type === "list") {
      // If all items serialize to the same object, return just one
      // This handles the case where a list of key-value rows should serialize
      // to a single structured object
      const serialized = result.data.map((item) => schema.serialize!(item));
      if (serialized.length > 0) {
        const first = JSON.stringify(serialized[0]);
        const allSame = serialized.every((s) => JSON.stringify(s) === first);
        if (allSame) {
          return JSON.stringify(serialized[0], null, 2);
        }
      }
      return JSON.stringify(serialized, null, 2);
    } else {
      const serialized = schema.serialize(result.data);
      return JSON.stringify(serialized, null, 2);
    }
  }

  return JSON.stringify(result.data, null, 2);
}

/** Render a single item as JSON line (for NDJSON streaming) */
export function renderJsonLine<T>(item: T, serialize?: (data: T) => unknown): string {
  const output = serialize ? serialize(item) : item;
  return JSON.stringify(output);
}