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ErrorsNEXUS_INVALID_PROVIDER

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_INVALID_PROVIDER

NEXUS_INVALID_PROVIDER means an entry in a module’s providers is malformed: a value with a lifetime, a module listed as a provider, an entry with no definition or with two, a deps list that is not an array, and the other reasons below. Nexus.create reports it inside NEXUS_BLUEPRINT_INVALID.

Reproduce NEXUS_INVALID_PROVIDER

TypeScript rejects most malformed entries where you write them. It reports TS2769 on the provide( call, and the error for the overload that takes useValue names this code:

Fails the type check

provide(REACTOR, { useValue: { output: 1.21 }, lifetime: 'transient' });
// TS2769: No overload matches this call. The error for the useValue overload ends with:
// Type '"transient"' is not assignable to type '"NEXUS_INVALID_PROVIDER: useValue and useExisting take no lifetime. Remove lifetime"'.

Core checks every entry again at create, for JavaScript callers and for lists TypeScript cannot see. The region reads its provider list from configuration at run time, and the entry sets a lifetime on a value. Without a plugin, core prints a one-line message that starts with the code and ends with the address of this page. With errors() from @nexusdi/errors registered (npm install @nexusdi/errors@next), the same error carries the full text and its fix.

import { Nexus, Token, defineModule, isNexusError } from '@nexusdi/core';
import type { ProviderEntry } from '@nexusdi/core';
import { errors } from '@nexusdi/errors';
 
interface IReactorCore {
  readonly output: number;
}
const REACTOR = new Token<IReactorCore>('ReactorCore');
 
// A provider list read from configuration at run time, which TypeScript
// cannot check: a value takes no lifetime.
const fromConfig: unknown[] = [
  { token: REACTOR, useValue: { output: 1.21 }, lifetime: 'transient' },
];
const Engineering = defineModule({
  name: 'Engineering',
  providers: fromConfig as ProviderEntry[],
});
 
const thin = await Nexus.create(Engineering).catch((error: unknown) => error);
if (!isNexusError(thin, 'NEXUS_BLUEPRINT_INVALID')) throw thin;
const line = thin.errors[0]?.message; // -> '[NEXUS_INVALID_PROVIDER] module=Engineering index=0 reason=value-with-lifetime. https://nexus.js.org/errors/NEXUS_INVALID_PROVIDER'
console.log(line);
 
const full = await Nexus.create(Engineering, { plugins: [errors()] }).catch(
  (error: unknown) => error,
);
if (!isNexusError(full, 'NEXUS_BLUEPRINT_INVALID')) throw full;
const text = full.errors[0]?.message.split('\n'); // -> ['[NEXUS_INVALID_PROVIDER] Engineering.providers[0] sets a lifetime on useValue; a value has none.']
console.log(text);

Try it: save the region as error.ts and run npx tsx error.ts. It prints the one-line message, whose reason is value-with-lifetime, then the full text as one line that says Engineering.providers[0] sets a lifetime on useValue. Then save the fix region below as fixed.ts and run npx tsx fixed.ts. It prints 1.21.

Fix NEXUS_INVALID_PROVIDER

NEXUS_INVALID_PROVIDER is fixed by correcting the entry the error names with module and index, as its reason says. A value takes no lifetime, because the container never builds it. Write entries with provide(), which TypeScript checks. A deps list that holds a value that is not a token has the reason bad-dep; see NEXUS_INVALID_TOKEN for the values that are no token.

import { Nexus, Token, defineModule, provide } from '@nexusdi/core';
 
interface IReactorCore {
  readonly output: number;
}
const REACTOR = new Token<IReactorCore>('ReactorCore');
 
const Engineering = defineModule({
  name: 'Engineering',
  providers: [provide(REACTOR, { useValue: { output: 1.21 } })],
});
 
await using ship = await Nexus.create(Engineering);
const output = ship.get(REACTOR).output; // -> 1.21
console.log(output);

Fields of InvalidProviderError

InvalidProviderError carries these fields:

  • module: the module whose providers holds the entry.
  • index: the position of the entry in that list.
  • reason: why the entry is malformed: static-deps-throws, static-deps-not-array, deps-in-both, options-not-object, not-a-provider, class-throws, bad-dep, deps-not-array, bad-injectable-lifetime, is-a-module, options-throw, provides-request, no-definition, several-definitions, bad-lifetime, use-class-not-a-class, value-with-lifetime, factory-not-a-function, alias-with-lifetime, alias-to-multi-token, bad-eager or eager-not-deferrable.
  • detail: the values the reason names, such as the module listed as a provider.
  • otherCopy: true when another copy of @nexusdi/core made the value the entry holds. Load one copy of @nexusdi/core.
ErrorsRegister a plugin