simple-properties-db/index.js

A simple file-based key-value properties database for Node.js

const fs = require('fs');
const path = require('path');

class SimplePropertiesDB {
    constructor(dbPath, options = {}) {
        const absPath = path.isAbsolute(dbPath) ? dbPath : path.join(process.cwd(), dbPath);
        this.DB_FILE_PATH = path.join(absPath, "db.properties");
        
        // Extract the directory part of the path
        const dir = path.dirname(this.DB_FILE_PATH);

        // Ensure the directory exists
        if (!fs.existsSync(dir)) {
            fs.mkdirSync(dir, { recursive: true });
        }

        // Then safely create the file
        if (!fs.existsSync(this.DB_FILE_PATH)) {
            fs.writeFileSync(this.DB_FILE_PATH, '');
        }
    }

    // Enhanced: parse string, number, boolean, and JSON object/array
    _parseValue(value) {
        if (value === "true") return true;
        if (value === "false") return false;
        if (value === "") return value;
        if (!isNaN(value)) return parseFloat(value);

        // Try to parse as JSON if it looks like an object or array
        if (
            typeof value === "string" &&
            ((value.startsWith("{") && value.endsWith("}")) ||
            (value.startsWith("[") && value.endsWith("]")))
        ) {
            try {
                return JSON.parse(value);
            } catch (e) {
                // Not valid JSON, return as string
            }
        }
        return value;
    }

    _loadData() {
        const data = fs.readFileSync(this.DB_FILE_PATH, "utf8");
        const lines = data.split("\n")
                .filter(line => line.trim() !== "")
                .filter(line => line.startsWith("#") || line.includes("="))

        const originLines = [];
        const parsedData = {};

        lines.forEach(line => {
            const isComment = line.startsWith("#");
            if (isComment) {
                originLines.push({type: "comment", value: line});
                return;
            }

            //get key and value
            const [key, ...valueArr] = line.split("=");
            const value = valueArr.join("=").trim();

            originLines.push({type: "property", key, value});
            parsedData[key] = this._parseValue(value);
        })

        return {originLines, parsedData};
    }

    get(key) {
        const {parsedData} = this._loadData();
        return parsedData[key];
    }

    getAll() {
        const {parsedData} = this._loadData();
        return parsedData;
    }

    set(key, value) {
        const {originLines} = this._loadData();

        // If value is an object or array, stringify it
        let storeValue = value;
        if (
            (typeof value === "object" && value !== null) ||
            Array.isArray(value)
        ) {
            storeValue = JSON.stringify(value);
        }

        const target = originLines.find(line => line.type === "property" && line.key === key);
        if (target) {
            target.value = storeValue;
        } else {
            originLines.push({type: "property", key, value: storeValue});
        }

        const data = originLines.map(line => line.type === "comment" ? line.value : `${line.key}=${line.value}`).join("\n");

        fs.writeFileSync(this.DB_FILE_PATH, data);
    }

    delete(key) {
        const {originLines} = this._loadData();
        const data = originLines.filter(line => line.type === "property" && line.key !== key).join("\n");
        fs.writeFileSync(this.DB_FILE_PATH, data);
    }

}

module.exports = SimplePropertiesDB;