addEventListener(
"install",
function (evt) {
evt.waitUntil(self.skipWaiting());
});
/**
* Given a multipart/form-data encoded string that we know to have only a single
* part, return the contents of the part. (MIME multipart encoding is too
* exciting to delve into.)
*/
function extractBlobFromMultipartFormData(text) {
const lines = text.split(/\r\n/g);
const firstBlank = lines.indexOf(
"");
const foo = lines.slice(firstBlank +
1, -
2).join(
"\n");
return foo;
}
self.addEventListener(
"fetch", event => {
const url =
new URL(event.request.url);
const mode = url.searchParams.get(
"mode");
if (mode ===
"synthetic") {
event.respondWith(
(async () => {
// This works even if there wasn't a body explicitly associated with the
// request. We just get a zero-length string in that case.
const requestBodyContents = await event.request.text();
const blobContents =
extractBlobFromMultipartFormData(requestBodyContents);
return new Response(
`<!DOCTYPE HTML><head><meta charset=
"utf-8"/></head><body>
<h1 id=
"url">${event.request.url}</h1>
<div id=
"source">ServiceWorker</div>
<div id=
"blob">${blobContents}</div>
</body>`,
{ headers: {
"Content-Type":
"text/html" } }
);
})()
);
}
else if (mode ===
"fetch") {
event.respondWith(fetch(event.request));
}
else if (mode ===
"clone") {
// In order for the act of cloning to be interesting, we want the original
// request to remain alive so that any pipes end up having to buffer.
self.originalRequest = event.request;
event.respondWith(fetch(event.request.clone()));
}
else {
event.respondWith(
new Response(
`<!DOCTYPE HTML><head><meta charset=
"utf-8"/></head><body>
<h1 id=
"error">Bad mode: ${mode}</h1>
<div id=
"source">ServiceWorker::Error</div>
<div id=
"blob">No,
this is an error.</div>
</body>`,
{ headers: {
"Content-Type":
"text/html" }, status:
400 }
)
);
}
});
