Broken Source Maps

[hediet]

TypeScript Version: 3.4.0-dev.20190311

Search Terms: Sourcemap

Code

function test(f: Function): { a: string } {
    f();
    return { a: "test" };
}

const { a: b } = test(() => {
    console.log("foo1");
    console.log("foo2");
});

const data = test(() => {
    console.log("foo3");
    console.log("foo4");
});

tsconfig.json

{
  "compilerOptions": {
    /* Basic Options */
    "target": "es5",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */
    "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */

    "strict": true,                           /* Enable all strict type-checking options. */

    "esModuleInterop": true,
    "sourceMap": true,
    "outDir": "out",
  },
  "include": ["index.ts"]
}

Expected behavior:
Both arrow functions are mapped properly.

Actual behavior:
Only the second arrow function is mapped properly.

Playground Link:
Source-Map-Visualization