This page documents the 0.4 release candidates of @nexusdi/core. The newest on npm is 0.4.0-rc.1. The documentation for 0.3.2, the current release, is at nexus.js.org. Try the release candidate.
NEXUS_INTERCEPTOR_LIFETIME
@nexusdi/interceptors reports NEXUS_INTERCEPTOR_LIFETIME when an interceptor is registered with the lifetime scoped or transient. The plugin builds every interceptor once, with the container, and every intercepted call of every scope runs through that one instance. The plugin’s check finds it while the graph compiles, before any constructor runs. Nexus.create and ship.load() reject with NEXUS_BLUEPRINT_INVALID holding it, and Nexus.check throws that error.
Reproduce NEXUS_INTERCEPTOR_LIFETIME
interceptors() reports NEXUS_INTERCEPTOR_LIFETIME for AUDIT registered with lifetime: 'transient'. Without a text pack, the message is one line that starts with the code and ends with the address of this page.
import { Nexus, Token, defineModule, provide } from '@nexusdi/core';
import { isNexusError } from '@nexusdi/core';
import { interceptor, interceptors } from '@nexusdi/interceptors';
import type { CallContext, Interceptor, Next } from '@nexusdi/interceptors';
interface IReactorCore {
output(): number;
}
const REACTOR = new Token<IReactorCore>('ReactorCore');
const AUDIT = new Token<Interceptor>('Audit');
const audited: string[] = [];
class AuditInterceptor implements Interceptor {
intercept(call: CallContext, next: Next) {
audited.push(`${call.provider.name} in ${call.scope ?? 'root'}`);
return next();
}
}
class FusionReactor implements IReactorCore {
output() {
return 1.21;
}
}
const Engineering = defineModule({
name: 'Engineering',
providers: [provide(REACTOR, { useClass: FusionReactor })],
exports: [REACTOR],
});
const error = await Nexus.create(Engineering, {
plugins: [
interceptors({
register: [
interceptor(AUDIT, {
useClass: AuditInterceptor,
lifetime: 'transient',
}),
],
global: [AUDIT],
}),
],
}).catch((caught: unknown) => caught);
const inner = isNexusError(error, 'NEXUS_BLUEPRINT_INVALID')
? error.errors[0]
: undefined;
const message = inner?.message; // -> '[NEXUS_INTERCEPTOR_LIFETIME] token=Audit detail=transient. https://nexus.js.org/errors/NEXUS_INTERCEPTOR_LIFETIME'
console.log(message);A scoped interceptor makes core report NEXUS_LIFETIME_VIOLATION as well, for the singleton registry that would capture it. It comes first in the errors list, and NEXUS_INTERCEPTOR_LIFETIME follows it. A transient interceptor reports this code alone.
Try it: run npm install @nexusdi/core@next @nexusdi/interceptors@next, save the region as lifetime.ts and run npx tsx lifetime.ts. It prints the one-line message: [NEXUS_INTERCEPTOR_LIFETIME] token=Audit detail=transient. and the address of this page. Change 'transient' to 'scoped' and run it again. The region prints the first error of the list, which is now the one of core: [NEXUS_LIFETIME_VIOLATION] path=interceptors registry,Audit lifetimes=singleton,scoped. and its address. Delete the lifetime line and run it again. The container builds, and the region prints undefined because there is no error to read. Put lifetime: 'transient' back and the first message returns.
Full text of NEXUS_INTERCEPTOR_LIFETIME with errors()
NEXUS_INTERCEPTOR_LIFETIME carries its full text and fix line when interceptorsText from @nexusdi/interceptors/text is passed to errors() from @nexusdi/errors, as errors({ text: [interceptorsText] }) in the plugins of Nexus.create. devtools({ text: [interceptorsText] }) words the error the same way.
import { Nexus, Token, defineModule, provide } from '@nexusdi/core';
import { isNexusError } from '@nexusdi/core';
import { errors } from '@nexusdi/errors';
import { interceptor, interceptors } from '@nexusdi/interceptors';
import type { CallContext, Interceptor, Next } from '@nexusdi/interceptors';
import { interceptorsText } from '@nexusdi/interceptors/text';
interface IReactorCore {
output(): number;
}
const REACTOR = new Token<IReactorCore>('ReactorCore');
const AUDIT = new Token<Interceptor>('Audit');
class AuditInterceptor implements Interceptor {
intercept(_call: CallContext, next: Next) {
return next();
}
}
class FusionReactor implements IReactorCore {
output() {
return 1.21;
}
}
const Engineering = defineModule({
name: 'Engineering',
providers: [provide(REACTOR, { useClass: FusionReactor })],
exports: [REACTOR],
});
const error = await Nexus.create(Engineering, {
plugins: [
errors({ text: [interceptorsText] }),
interceptors({
register: [
interceptor(AUDIT, {
useClass: AuditInterceptor,
lifetime: 'transient',
}),
],
global: [AUDIT],
}),
],
}).catch((caught: unknown) => caught);
const inner = isNexusError(error, 'NEXUS_BLUEPRINT_INVALID')
? error.errors[0]
: undefined;
const lines = inner?.message.split('\n'); // -> ['[NEXUS_INTERCEPTOR_LIFETIME] the interceptor Audit is transient, and interceptors are singletons.', ' Fix: remove its lifetime, and read request data from call.instance.']
console.log(lines?.join('\n'));Try it: run npm install @nexusdi/errors@next, save the region as full.ts and run npx tsx full.ts. It prints the two-line message with its Fix: line: [NEXUS_INTERCEPTOR_LIFETIME] the interceptor Audit is transient, and interceptors are singletons. and Fix: remove its lifetime, and read request data from call.instance.
Fix NEXUS_INTERCEPTOR_LIFETIME
NEXUS_INTERCEPTOR_LIFETIME goes away when the interceptor’s registration names no lifetime, or names singleton. An interceptor that needs data from one request reads it from the call: call.instance is the service the call runs on, and call.scope is the id of the scope that built it, or null at the root.
import { Nexus, Token, defineModule, provide } from '@nexusdi/core';
import { interceptor, interceptors } from '@nexusdi/interceptors';
import type { CallContext, Interceptor, Next } from '@nexusdi/interceptors';
interface IReactorCore {
output(): number;
}
const REACTOR = new Token<IReactorCore>('ReactorCore');
const AUDIT = new Token<Interceptor>('Audit');
const audited: string[] = [];
class AuditInterceptor implements Interceptor {
intercept(call: CallContext, next: Next) {
audited.push(`${call.provider.name} in ${call.scope ?? 'root'}`);
return next();
}
}
class FusionReactor implements IReactorCore {
output() {
return 1.21;
}
}
const Engineering = defineModule({
name: 'Engineering',
providers: [provide(REACTOR, { useClass: FusionReactor })],
exports: [REACTOR],
});
await using ship = await Nexus.create(Engineering, {
plugins: [
interceptors({
register: [interceptor(AUDIT, { useClass: AuditInterceptor })],
global: [AUDIT],
}),
],
});
const output = ship.get(REACTOR).output(); // -> 1.21
console.log(output);
const entries = audited; // -> ['ReactorCore in root']
console.log(entries);The fix region differs from the reproduce region in the lifetime line, which it leaves out, and in what follows: it calls output() on the container it keeps and prints what the interceptor saw.
Try it: save the region as fixed.ts and run npx tsx fixed.ts. It prints 1.21 and [ 'ReactorCore in root' ]. Add lifetime: 'transient' to the registration and run it again. npx tsc accepts the file, and npx tsx fixed.ts throws an uncaught BlueprintError and prints a stack trace headed BlueprintError: [NEXUS_BLUEPRINT_INVALID] 1 error., whose message goes on with the line [NEXUS_INTERCEPTOR_LIFETIME] token=Audit detail=transient. and the address of this page. Remove the line and the program prints its two lines again.
Method Interceptors covers the singleton rule.
Fields of InterceptorError
code:'NEXUS_INTERCEPTOR_LIFETIME'.reason:nullfor this code.token: the interceptor token’s name.target:nullfor this code.method:nullfor this code.state:nullfor this code.detail: the lifetime found,['transient']or['scoped'].