Nostics

Nostics attacks a narrow, real problem: errors from libraries are usually unsearchable strings that give users no next step. Its answer is a catalog. You call defineDiagnostics with a codes map; each code defines why, fix, and data — inline strings or functions whose params are inferred and required at the call site. Because the keys become callable handles, diagnostics.NUXT_B2011({ src, mode }) both constructs the Diagnostic and runs every registered reporter, returning the instance for you to throw or inspect. That single mechanic is the whole product, and it's a good one: TypeScript keeps your message and fix in sync with the data you pass, and the docsBase function (or string, or per-code override, or false to omit) turns a code into a docs URL like https://nuxt.com/e/b2011. The code format is a convention rather than a rule — the docs recommend <PREFIX>_<CATEGORY><NUMBER> with letters like C for config, R for runtime, B for build, D for deprecation, W for warning, and E for error, but an explicit name like invalidDate works and reads better for small catalogs. The important rule is that a published code is never renamed or reused. Reporters are pluggable: createConsoleReporter is shown in the docs, and the site documents NDJSON file output, HTTP POST, and bring-your-own reporters, plus custom formatters. The two Vite plugins add the practical edge — dev collection forwards browser diagnostics to a local log file, and production stripping removes report-only diagnostics and their catalog text from bundles, which also means code stability is a correctness requirement, not just tidiness. The honest limits: you have to define codes and wire up reporters yourself, the tool is a development-time diagnostic system rather than a logger or production monitor, and it targets the Node.js and Vite ecosystems. Small libraries with a handful of errors may find the catalog setup heavier than the payoff. It is a developer tool, not an AI product — there is no model underneath.