node-red-contrib-fff-random-number 2.0.0

Node-RED node that generates random numbers with configurable range, precision and an optional cryptographically secure source.

npm install node-red-contrib-fff-random-number

node-red-contrib-fff-random-number

A Node-RED node that generates a pseudo-random number within a configurable range and decimal precision. The result is written to msg.payload as a Number and shown in the node status.

The fff prefix stands for FishFarmFeeder, the project this node was originally built for. The node itself is general-purpose.

Installation

Recommended: install from the Node-RED palette manager (Menu → Manage palette → Install) and search for node-red-contrib-fff-random-number.

Manual install from your Node-RED user directory (default ~/.node-red on Linux/macOS, %HOMEPATH%\.node-red on Windows):

npm install node-red-contrib-fff-random-number

Restart Node-RED. The node appears in the function category as random number.

Configuration

Per-message overrides

Any field above can be overridden on a per-message basis. If the property is not set on the message, the editor value is used.

If an override cannot be coerced to a finite number, the node calls node.error() and does not emit a message.

Output

The incoming message is forwarded unchanged except for:

• msg.payload — the generated number (Number).

The status badge shows the last value produced.

Example

A working flow is included in examples/basic-flow.json. Import it from Node-RED with Menu → Import → select file. It contains:

• An inject node that triggers the default configuration.
• An inject node that overrides min, max and decimals via the message.
• A debug node to inspect msg.payload.

Notes and caveats

• Default source is not cryptographically secure. With cryptoSecure disabled (the default), the node uses Math.random(). Do not use that mode for tokens, keys, or any security-sensitive value.
• cryptoSecure is not a key generator. It draws from crypto.randomBytes, which is suitable for non-statistical use cases where Math.random would be too biased, but it is not a substitute for purpose-built credential or token generators.
• max and rounding. When decimals > 0, the result is rounded with Number.prototype.toFixed. Values close to max can round up to max itself.
• min > max. The node treats [min, max] as an interval and does not reorder. If min > max, you will get values in [max, min] with the sign of (max - min) applied. Validate inputs upstream if this matters.
• Invalid overrides cause an error. If msg.min, msg.max or msg.decimals is present but not coercible to a finite number, the node emits node.error() and does not forward the message.

Requirements

• Node-RED ≥ 3.0
• Node.js ≥ 18

Migrating from 1.x

The 2.0 release renames the registered node type from random-number to fff-random-number so it cannot collide with other community packages. Flows exported under 1.x reference the old type and will fail to load until they are updated:

1. Open the flow file (.json) or the Node-RED editor.
2. Replace every "type": "random-number" with "type": "fff-random-number".
3. Re-deploy.

The configuration fields (min, max, decimals) and the message overrides are unchanged. A new optional field, cryptoSecure, is added.

Contributing

Bug reports and pull requests are welcome. See CONTRIBUTING.md for the workflow.

License

ISC © Carlos Fontán