E024: random-requires-initialization

Metadata

• Code: E024
• Rule: random-requires-initialization
• Status: Preview since v0.0.1
• Quick fix: sometimes available

What it does

Requires random generator initialization before random value generation calls.

Why is this bad?

Calling random.uint256(...) or random.range(...) before random.initialize(...) / random.initializeBy(...) can lead to predictable or invalid randomness behavior.

Example

fun main() {
    val x = random.uint256();
E024: random generator must be initialized before `random.uint256`/`random.range` call
}

Use instead:

fun main() {
    random.initializeBy(123);
    val x = random.uint256();
}

Behavior notes

This check is control-flow aware. It does not just scan text for "init before use". It builds a control-flow graph (CFG) and verifies that for each random.uint256(...) / random.range(...) call, initialization is guaranteed on all reachable execution paths before that call.

It also follows function calls, so helper functions that initialize random are taken into account.