Cannot transpile TypeScript containing async await

Question

When trying to transpile the following TypeScript code containing async and await keywords

async function foo() {
    await bar();
}

I get the following error

src/aa.ts(1,7): error TS1005: ';' expected.
src/aa.ts(2,11): error TS1005: ';' expected.

The result is a .js file with this content

async;
function foo() {
    await;
    bar();
}

I'm using these tsc options: -t es6 -m commonjs, following instructions on this MSDN blog. I have TypeScript 1.8.9 installed.

Any ideas?

Answer 1

For some reason the TypeScript compiler did not recognize the async and await keywords. This happened even though the TypeScript compiler version was of the correct version.

What I did to solve this is uninstall tsc and install typescript globally:

npm uninstall --global tsc
npm install --global typescript

Answer 2

I encountered a similar issue with an asynchronous arrow function:

async resource_type => some_value
// error TS1005: ',' expected.

Typescript was happy once I wrapped my function parameter in parenthesis:

async (resource_type) => some_value