naming-conventions

naming-conventions

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Overview

Move on Sui has specific naming conventions that differ from what AI agents typically generate from training data. This skill covers every naming pattern from the official code quality checklist.

All patterns sourced from https://move-book.com/guides/code-quality-checklist

Error Constants: EPascalCase with #[error]

Error constants MUST use PascalCase with an E prefix. Do NOT use SCREAMING_SNAKE_CASE.

Use the #[error] attribute to attach human-readable messages to error constants. When an abort occurs, the message is included in the error output, making debugging much easier for users and support.

// WRONG
const NOT_AUTHORIZED: u64 = 0;
const INSUFFICIENT_BALANCE: u64 = 1;

// CORRECT — with #[error] for readable abort messages
#[error]
const ENotAuthorized: vector<u8> = b"Caller is not authorized to perform this action";
#[error]
const EInsufficientBalance: vector<u8> = b"Insufficient balance for this operation";

// Also valid — u64 without #[error] (less informative on abort)
const ENotAuthorized: u64 = 0;
const EInsufficientBalance: u64 = 1;

When using #[error], the constant type is vector<u8> (a byte string message) instead of u64. The compiler assigns numeric codes automatically. Prefer #[error] for all new code — it produces clearer error output in explorers, wallets, and logs.

Regular Constants: ALL_CAPS

Non-error constants use uppercase snake_case. This is the opposite of error constants.

// WRONG
const MyConstant: vector<u8> = b"hello";
const feeNumerator: u64 = 3;

// CORRECT
const MY_CONSTANT: vector<u8> = b"hello";
const FEE_NUMERATOR: u64 = 3;

Capability Structs: Cap Suffix

Any struct that represents a capability (authorization to perform actions) MUST be suffixed with Cap.