Auto import generates wrong module specifier for `a/index.ts` when `a.ts` exists

[andrewbranch]

TypeScript Version: 3.8.1-rc

Search Terms: auto import index

Code

// tsconfig.json
{
  "compilerOptions": {
    "module": "commonjs" // ensures `importModuleSpecifierEnding` defaults to `Ending.Minimal`
  }
}

// a/index.ts
export const aIndex = 0;

// a.ts
export {}

// index.ts
aIndex/* auto-import here */

Expected behavior:
Module specifier from auto-import is "./a/index"

Actual behavior:
Module specifier is "./a"

Related Issues: #36725 #24779