error TS6054: File 'tests/cases/compiler/a.js' has unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts'.


!!! error TS6054: File 'tests/cases/compiler/a.js' has unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts'.
==== tests/cases/compiler/a.js (0 errors) ====
    declare var v;