Changelog - 2026-10-06

The container names a cycle and caches any singleton

Bug Fix Behavior Change

In one line. Seven defects in @venizia/ignis-inversion are fixed. The container now behaves the same whatever the class names, the values or the key types.

Before	Now
A subclass's property @inject was written into its parent's metadata, so the parent and every sibling then required that binding	Property metadata is copy-on-write per class, like constructor metadata
@inject({ target: X, isOptional: true }) threw when X was never registered	It resolves to undefined, as an optional key does
A cycle (A -> B -> A) ended in RangeError: Maximum call stack size exceeded	It throws Circular dependency | services.A -> services.B -> services.A
A singleton that cached null, false, 0 or '' survived container.clear()	clear() clears every cached value
A singleton that answered undefined ran again on every read	It runs once, like any singleton
Symbol('x') and another Symbol('x') shared one binding	They are two keys. Symbol.for('x') is still one key everywhere
A missing { namespace, key } was reported as [object Object]	The message names namespace.key
Injection metadata carrying both a class and a key resolved by the key	The class wins - the key its registration recorded - and the key is the fallback for a class nothing recorded. @inject itself still takes one or the other; this serves metadata a framework writes

The cycle check is not on the hot path. A cached singleton or a toValue binding builds nothing and skips it. Any other read counts its nesting depth, and tracks keys only past 64 levels - deeper than any real graph. Measured, median of 9 runs: singleton, transient and provider reads all within noise of before. A cycle through an await is not detected.

Unchanged on purpose: a singleton promise that rejects stays cached until clear(). Dropping it would need a handler on the promise, and that handler would silence the unhandled-rejection report of a caller that never awaits it.

Who is affected

• A @provide method or a singleton provider that returns undefined, and expects to be asked again later. It is now asked once. Return the value when it exists, or bind it transient.
• Code that caught the old RangeError from a cycle. It now gets an ApplicationError naming the path.
• Code that looks a symbol-keyed binding up by its string (String(symbol)). The second symbol with a description is stored as Symbol(x)#2. Look it up by the symbol.
• Everyone else. No change, beyond the errors that now name what failed.

Files: packages/inversion/src/modules/container/base.ts, packages/inversion/src/modules/container/container.ts, packages/inversion/src/modules/binding/binding.ts, packages/inversion/src/modules/registry/registry.ts