json-compact/src/index.ts

Create a downsized json file from tabular data, ie [{...},{...}] Optimized for GPT/LLM processing.

interface DataObject {
  [key: string]: any;
}

const JSONcompact = {
  compact(
    data: DataObject[] | string,
    description?: string,
    roundToDecimalPlaces?: number
  ): { description: string; columns: string[]; rows: (number | null)[][] } {
    let dataArray: DataObject[];

    if (typeof data === "string") {
      try {
        dataArray = JSON.parse(data);
      } catch (error) {
        throw new Error("Invalid JSON data");
      }
    } else {
      dataArray = data;
    }

    if (!Array.isArray(dataArray)) {
      throw new Error("Input data must be an array of objects");
    }

    const defaultDescription =
      "This table's 'columns' list field names, and 'rows' are arrays of corresponding values in the same sequential order. 'null' represents missing data. All numerical fields should be provided as numbers, not strings. Ensure full dataset is included for each separate request to maintain data continuity.";

    const columns: string[] = [];
    dataArray.forEach((obj) => {
      Object.keys(obj).forEach((key) => {
        if (!columns.includes(key)) {
          columns.push(key);
        }
      });
    });

    const rows = dataArray.map((obj) =>
      columns.map((key) => {
        let value = obj[key] ?? null;
        if (
          typeof roundToDecimalPlaces === "number" &&
          typeof value === "number" &&
          Number.isFinite(value)
        ) {
          value = parseFloat(value.toFixed(roundToDecimalPlaces));
        }
        return value;
      })
    );

    return { description: description ?? defaultDescription, columns, rows };
  },
  compactedJSON(
    data: DataObject[] | string,
    description?: string,
    roundToDecimalPlaces?: number
  ): string {
    const compacted = JSONcompact.compact(
      data,
      description,
      roundToDecimalPlaces
    );
    return JSON.stringify(compacted);
  },
  expand(
    data:
      | { description: string; columns: string[]; rows: (number | null)[][] }
      | string
  ): DataObject[] {
    let compacted: {
      description: string;
      columns: string[];
      rows: (number | null)[][];
    };

    if (typeof data === "string") {
      try {
        compacted = JSON.parse(data);
      } catch (error) {
        throw new Error("Invalid JSON data");
      }
    } else {
      compacted = data;
    }

    if (!Array.isArray(compacted.rows)) {
      throw new Error("Input data must be an array of objects");
    }

    const dataArray: DataObject[] = [];
    compacted.rows.forEach((row) => {
      const obj: DataObject = {};
      row.forEach((value, index) => {
        obj[compacted.columns[index]] = value;
      });
      dataArray.push(obj);
    });

    return dataArray;
  },
  expandedJSON(
    data:
      | { description: string; columns: string[]; rows: (number | null)[][] }
      | string
  ): string {
    const expanded = JSONcompact.expand(data);
    return JSON.stringify(expanded);
  },
};

export default JSONcompact;