Diagnostics

Diagnostics

The class runtime can capture an introspection report of everything it registered — routes, providers, duplicate-route collisions, circular dependencies, and bootstrap timing — so you can debug and inspect a class-based app. Diagnostics are opt-in and zero-cost when disabled: when diagnostics is not set, no timings are measured, no report is collected, and nothing is stored.

Enabling

Turn it on in registerControllers:

import { createApp } from 'nextrush';
import { registerControllers, getClassDiagnostics } from 'nextrush/class';

const app = createApp();
await registerControllers(app, {
  controllers: [UserController],
  diagnostics: true,
});

const report = getClassDiagnostics(app);   // DiagnosticsReport | undefined

getClassDiagnostics(app) returns the report after registration completes, or undefined if diagnostics were not enabled.

What the report contains

The DiagnosticsReport is a read-only snapshot with five fields:

Field	Type	Holds
routes	RouteEntry[]	Every registered route: method, path (prefix applied), controller
providers	ProviderEntry[]	Every provider in the DI graph: token, dependencies
duplicateRoutes	DuplicateRoute[]	Routes registered more than once (method + path collision), with the registration count
circularDependencies	CircularDependency[]	Cycles in the provider graph, as an array of tokens
timings	TimingEntry[]	Bootstrap stage name + duration in ms

const { routes, duplicateRoutes, timings } = getClassDiagnostics(app)!;

for (const route of routes) {
  console.log(route.method, route.path);
}

for (const dup of duplicateRoutes) {
  console.warn(`Duplicate: ${dup.method} ${dup.path} (${dup.count}x)`);
}

When to use it

• Debugging — confirm which routes and providers actually registered, and how long each bootstrap stage took.
• Dev tooling — a scoreboard, a route table, or a startup-profile dump.
• Detecting collisions — spot duplicate routes and provider cycles at build time instead of at request time.

The report is keyed to the Application instance, so inspect the same app object you registered into.

Related

• Controllers and Decorators — the registration options and lifecycle
• Modules — module composition (register via registerControllers underneath)
• Architecture — where the class runtime sits over the functional core
• Diagnostics reference: https://0xtanzim.github.io/nextRush/docs/reference/class/controllers