What problem does it solve? TypeScript projects often compile successfully but fail at runtime in Node.js ESM with errors like ERR_MODULE_NOT_FOUND, directory import failures, or "works in tsx but not in node dist". This Skill resolves the mismatch between what TypeScript emits, what Node actually resolves, and what files exist on disk. ## Core Features & Use Cases - Runtime Mode Diagnosis: Determines whether the real execution contract is compiled JS (tsc -> dist -> node), native .ts type stripping, or a runner like tsx/ts-node, and checks each layer for drift. - Config and Specifier Alignment: Guides choices for module, moduleResolution, verbatimModuleSyntax, rewriteRelativeImportExtensions, .js vs .ts relative specifiers, and package.json "type"/"exports"/"imports" versus tsconfig.paths aliases. - Failure Triage: Maps concrete errors such as ERR_MODULE_NOT_FOUND, ERR_UNSUPPORTED_DIR_IMPORT, and "Cannot use import statement outside a module" to their likely mismatch seam and first discriminating check. - Use Case: A service passes tests under tsx but crashes in production with ERR_MODULE_NOT_FOUND after tsc build; the Skill inspects the start command, package.json, effective tsconfig, and emitted dist files to pinpoint the specifier or alias drift and recommend the smallest fix. ## Quick Start Ask the assistant to diagnose why your TypeScript project compiles but fails when run with node dist, and have it inspect your package.json, tsconfig, and emitted import strings.
