enhanced-resolve research

webpack enhanced-resolve configuration behavior relevant to TypeScript extension aliases.

Extension aliases

enhanced-resolve does not substitute TypeScript extensions by default. Its default extensions are .js, .json, and .node (resolver options).

extensionAlias is an explicit opt-in policy. Candidate order determines precedence: '.js': ['.ts', '.js'] prefers TypeScript, while '.js': ['.js', '.ts'] preserves the requested JavaScript file first (implementation, tests).