HostComponentInfo

Kind: Interface

Source: packages/core/injector/instance-wrapper.ts

Part of: Core

HostComponentInfo describes metadata associated with the component that hosts a provider or dependency instance. It identifies the host through its injection token and indicates whether the host belongs to a durable dependency tree via isTreeDurable.

Properties

Diagram

mermaid
graph LR
  Wrapper[Instance Wrapper] --> HostInfo[HostComponentInfo]
  HostInfo --> Token[token: InjectionToken]
  HostInfo --> Durable[isTreeDurable: boolean]
  Token --> HostComponent[Host Component / Provider]
  Durable --> Tree[Dependency Tree Durability]

Usage

ts
import type { InjectionToken } from '@nestjs/common';
import type { HostComponentInfo } from '@nestjs/core/injector/instance-wrapper';

class UsersService {}

const hostComponentInfo: HostComponentInfo = {
  token: UsersService as InjectionToken,
  isTreeDurable: true,
};

// Store this metadata when creating or inspecting an instance wrapper.
function registerHost(info: HostComponentInfo) {
  console.log(`Host token: ${String(info.token)}`);
  console.log(`Tree durable: ${info.isTreeDurable}`);
}

registerHost(hostComponentInfo);

AI Coding Instructions

• Preserve both fields when cloning, transforming, or forwarding host component metadata.
• Use the same injection token that identifies the owning provider or component; do not substitute an instance value.
• Set isTreeDurable based on dependency-tree durability rules, especially when working with scoped providers.
• Treat token as an InjectionToken, which may be a class, string, symbol, or custom token.
• Keep this interface focused on host metadata; lifecycle and instance state belong on the surrounding instance wrapper.

Used by

2 references from 2 files. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

Imported by (2)

• DurableContextIdStrategy — integration/inspector/src/durable/durable-context-id.strategy.ts:6
• TenantContext — integration/scopes/src/durable/durable-context-id.strategy.ts:4