34 lines
1 KiB
JavaScript
34 lines
1 KiB
JavaScript
var xhr;
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var myself;
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async function handleLoadstart() {
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try {
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xhr.open("POST", "FOOBAR", false);
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// This will potentially queue another "loadstart" event
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// before we can catch (err). But the order should be
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// guaranteed, that is the first postMessage arriving at
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// our parent is from the first catch (err).
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xhr.send();
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myself.postMessage("MissingError");
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} catch (err) {
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if (err instanceof DOMException) {
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// This is what we expect to happen on the first error
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// and the parent will check for this to arrive.
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myself.postMessage("DOMException");
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} else {
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myself.postMessage("OtherError");
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}
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// Let's ensure we still bail out from the processing.
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xhr.removeEventListener("loadstart", handleLoadstart, true);
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throw err;
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}
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}
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self.onmessage = async function () {
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xhr = new XMLHttpRequest({ mozAnon: false });
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myself = self;
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xhr.addEventListener("loadstart", handleLoadstart, true);
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xhr.open("POST", "FOOBAR", false);
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xhr.send();
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postMessage("TERMINATE");
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};
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