Javascript await reading text file

Question

This is probably dead simple, but I can't quite figure it out. I simply want to read the contexts of a text file into a variable. What I have is:

async function load(path) {
    try {
        const response = await fetch(path);
        const text = await response.text();
        return text;
    } catch (err) {
        console.error(err);
    }
}

var source_text = load(source_text_path);
console.log(source_text);

To my mind, this should work but only the pending promise is returned and not the text, thought I thought it was awaiting properly.

You need to await load because it is asynchronous (or chain it with a then) — possum
– possum, Commented Oct 11, 2022 at 15:36
I was also thinking this, but awaiting load when I create source_text gives this console error: await is only valid in async functions and the top level bodies of modules. — Thomas Nicholson
– Thomas Nicholson, Commented Oct 11, 2022 at 15:49
So you need to do just that - put it in an async function. If your intent is to get the value from a synchronous call even though the operation is asynchronous, then I'm afraid you need to rethink your approach, because information can't time-travel back into the synchronous call result when it arrives only later on. If this is for initialization: A common aporoach is to have these things in asynchronous init functions which some (also async) main function will call (and await) on startup. The synchronous top-level code then does main().catch(e => { console.error(e); process.exit(1) }) — CherryDT
– CherryDT, Commented Oct 11, 2022 at 15:54
Alternatively, you could change your project to use ES modules, because then (as the error suggested as well) you can use await in top-level code (because importing a module is in itself an asynchronous operation, unlike require). — CherryDT
– CherryDT, Commented Oct 11, 2022 at 15:56

Shreenil Patel · Accepted Answer · 2022-10-11 15:37:02Z

1

You need to wait for the load method.

var source_text = await load(source_text_path);

OR

load(source_text_path).then(e => console.log(e))

answered Oct 11, 2022 at 15:37

Shreenil Patel

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Thomas Nicholson Over a year ago

I was also thinking this, but awaiting the call to load() when I create source_text gives this console error: await is only valid in async functions and the top level bodies of modules.

Abdellah Hariti · Accepted Answer · 2022-10-11 15:38:29Z

1

The function is indeed awaiting as it should, but since it's async, it will always result in a Promise<things> when you return thing.

Which means you should either await it elsewhere:

var source_text = await load(source_text_path);

or then it:

load(source_text_path).then((source_text) => {
  console.log(source_text);
})

answered Oct 11, 2022 at 15:38

Abdellah Hariti

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