Boolean variables (prefix required)

• Selector: variable with types: ["boolean"]
• Format: PascalCase
• Required prefixes: is, are, should, has, can, did, will

Why This Rule

Boolean variables should read like yes/no questions. This makes conditionals read like natural language and eliminates ambiguity.

Without prefixes:

if (loading && permission && retry) {
}
// Is "loading" a boolean or a string status?
// Is "permission" a boolean or an object?

With prefixes:

if (isLoading && hasPermission && shouldRetry) {
}
// Crystal clear - all booleans, reads like English

Why these specific prefixes:

• is: State or condition (isActive, isVisible)
• are: Plural state (areItemsSelected, areUsersOnline)
• has: Possession or presence (hasAccess, hasError)
• should: Conditional logic (shouldRetry, shouldValidate)
• can: Capability or permission (canEdit, canDelete)
• did: Past action (didComplete, didTimeout)
• will: Future action (willExpire, willReset)

This convention is nearly universal in professional codebases and recommended by every major style guide.

References:

• TypeScript ESLint - Naming Convention for Boolean Variables

✅ Good

const isActive: boolean = true; // WHY: 'is' prefix makes intention clear and reads like a boolean
const hasPermission: boolean = false; // WHY: 'has' prefix shows possession/presence
const shouldRetry: boolean = true; // WHY: 'should' prefix indicates conditional behavior

❌ Bad

const active: boolean = true; // WHY: missing prefix — unclear if boolean
const enabled: boolean = false; // WHY: ambiguous name without a boolean prefix