du-node-utils

dueros node utils

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[npm-url]: https://npmjs.com/package/du-node-utils
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[download-url]: https://npmjs.com/package/du-node-utils
[david-image]: https://img.shields.io/david/imcooder/du-node-utils.svg
[david-url]: https://david-dm.org/imcooder/du-node-utils

Installation

``bash
npm install du-node-utils
`

Usage

`javascript
const util = require('du-node-utils');
`

You can also import specific modules:

`javascript
const { string, network, id } = require('du-node-utils');
// or
const string = require('du-node-utils/lib/string');
`

API Reference

$3

| Method | Description |
|--------|-------------|
| toString(obj) | Convert object to string |
| toObject(str) | Parse JSON string to object |
| format(source, data) | Format string with #{key} placeholders |
| trimStringLeft(str, charset) | Trim specified characters from left |
| trimStringRight(str, charset) | Trim specified characters from right |
| trimString(str, charset) | Trim specified characters from both sides |
| simplifyString(str) | Keep only alphanumeric and underscores, convert to lowercase |
| formatErrorMsg(message) | Format error message |

`javascript
// Example
util.format('Hello #{name}!', { name: 'World' });
// Returns: "Hello World!"

util.simplifyString('Hello World!');
// Returns: "hello_world"
`

$3

| Method | Description |
|--------|-------------|
| getIPAdress() | Get local IPv4 address |
| ip2int(ip) | Convert IP to integer (network byte order) |
| ip2long(ip) | Convert IP to long integer |
| parseIp(ipString) | Parse IP address from string |
| getClientIpFromHttpHeader(headers) | Get client IP from HTTP headers |
| postJson(options, body) | Send POST JSON request (returns Promise) |
| makeRpcUrl(host) | Generate RPC URL |

`javascript
// Example
util.getIPAdress();
// Returns: "192.168.1.100"

util.ip2long('192.168.1.1');
// Returns: 3232235777
`

$3

| Method | Description |
|--------|-------------|
| makeUUID(trim) | Generate UUID, optionally remove hyphens |
| randomInt(min, max) | Generate random integer in range [min, max) |
| randomString(len) | Generate random alphanumeric string |
| makeUidPostfix() | Generate hexadecimal UID postfix |
| makeUserId(appid, uid, cuid) | Generate user ID |
| parseUserid(userId) | Parse user ID |
| makeDbKey(uid) | Generate database key |
| setSessionPrefix(prefix) | Set custom session ID prefix |
| generateSessionId() | Generate unique session ID |

`javascript
// Example
util.makeUUID(true);
// Returns: "550e8400e29b41d4a716446655440000"

util.randomString(8);
// Returns: "a3f7e9b2"

// Session ID with default random prefix
util.generateSessionId();
// Returns: "a3f7e9b2c1d41735088400123x9y8z"

// Session ID with custom prefix
util.setSessionPrefix('myapp');
util.generateSessionId();
// Returns: "myapp1735088400123x9y8z"
`

#### generateSessionId Format

The session ID consists of three parts:

`
{prefix}{timestamp}{randomSuffix}
`

| Part | Description | Example |
|------|-------------|---------|
| prefix | Custom prefix (via setSessionPrefix) or random 12-char string | a3f7e9b2c1d4 |
| timestamp | 13-digit millisecond timestamp | 1735088400123 |
| randomSuffix | 5-character random string (base36) | x9y8z |

Example breakdown:
`
a3f7e9b2c1d41735088400123x9y8z
|___________|____________|____|
prefix timestamp rand
(12 char) (13 digit) (5 char)
`

- prefix: Identifies the app instance. Use setSessionPrefix() to set a custom value, otherwise a random string is generated at module load.
- timestamp: Provides natural chronological ordering.
- randomSuffix: Prevents collisions when multiple IDs are generated within the same millisecond.

#### Use Cases

- Request Tracing: Track requests across microservices by passing session ID in headers
- Log Correlation: Group related log entries using the same session ID
- User Session Management: Identify user sessions in web applications
- Distributed Systems: Trace operations across multiple nodes (prefix identifies the origin node)
- Debugging: Quickly locate all logs for a specific request or session

$3

| Method | Description |
|--------|-------------|
| parseData(data, schema) | Parse data according to schema |
| parseArgs(args) | Parse command line arguments |

`javascript
// Example
const schema = {
name: { type: 'string' },
age: { type: 'int' },
active: { type: 'bool' }
};
util.parseData({ name: 'John', age: '25', active: 'true' }, schema);
// Returns: { name: 'John', age: 25, active: true }
`

$3

| Method | Description |
|--------|-------------|
| now() | Get current timestamp in milliseconds |
| formatDate(date, fmt) | Format date with pattern |

`javascript
// Example
util.now();
// Returns: 1735088400123

util.formatDate(new Date(), 'yyyy-MM-dd hh:mm:ss');
// Returns: "2024-01-09 14:30:00"
`

$3

| Method | Description |
|--------|-------------|
| arrayToMap(array, key) | Convert array to map using specified key |
| toArray(obj) | Convert object to array |
| clone(obj) | Shallow clone object |
| deepClone(obj) | Deep clone object |
| selectByIDC(configs, idc) | Filter configs by IDC |

`javascript
// Example
const users = [
{ id: 1, name: 'Alice' },
{ id: 2, name: 'Bob' }
];
util.arrayToMap(users, 'id');
// Returns: { 1: { id: 1, name: 'Alice' }, 2: { id: 2, name: 'Bob' } }

util.deepClone({ a: { b: 1 } });
// Returns: { a: { b: 1 } } (new object)
`

$3

| Method | Description |
|--------|-------------|
| md5(str) | Calculate MD5 hash of string |

`javascript
// Example
util.md5('hello');
// Returns: "5d41402abc4b2a76b9719d911017c592"
`

$3

| Method | Description |
|--------|-------------|
| invokeCallback(cb, ...args) | Safely invoke callback function |
| json(status, msg, data) | Build JSON response object |
| stringArrayBuffer(str) | Convert string to ArrayBuffer |

`javascript
// Example
util.json(0, 'success', { id: 1 });
// Returns: { status: 0, msg: 'success', data: { id: 1 } }
``

License

MIT