query-binding.md

title	query-binding: Descriptor disagrees with parameter
description	Keep explicit query descriptors in positional sync.

What

The number of @query descriptors differs from the runtime method parameter count, or a provable constructor token type disagrees with its parameter. Rule: arc-core/query-binding. Count checks work without a TypeScript program; type comparisons need one.

Why

Arc binds explicit query arguments and services in declaration order and counts parameters using method.length (before the first default or rest parameter). Argument wire names need not match TypeScript parameter names. Bare @query() uses inferred metadata and is not checked by this rule.

Bad

@query(argument('id', TaskId), argument('limit', Number))
static byId(id: TaskId, limit = 10) { return tasks.byId(id); }

Good

@query(argument('taskId', TaskId))
static byId(id: TaskId) { return tasks.byId(id); }