53 lines
1.2 KiB
Rust
53 lines
1.2 KiB
Rust
use std::pin::Pin;
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use std::task::{Context, Poll};
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use futures_util::sink::Sink;
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use wasm_bindgen::prelude::*;
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/// A Sink that always errors on the first write.
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pub struct FailingSink {
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failed: bool,
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}
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impl FailingSink {
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pub fn new() -> Self {
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Self { failed: false }
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}
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}
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impl Default for FailingSink {
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fn default() -> Self {
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Self::new()
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}
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}
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impl Sink<JsValue> for FailingSink {
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type Error = JsValue;
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fn poll_ready(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
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Poll::Ready(Ok(()))
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}
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fn start_send(mut self: Pin<&mut Self>, _item: JsValue) -> Result<(), Self::Error> {
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if !self.failed {
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self.failed = true;
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// Return an error on first write
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Err(JsValue::from_str("intentional error"))
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} else {
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Ok(())
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}
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}
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fn poll_flush(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
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if self.failed {
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Poll::Ready(Err(JsValue::from_str("sink has failed")))
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} else {
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Poll::Ready(Ok(()))
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}
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}
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fn poll_close(self: Pin<&mut Self>, _cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
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Poll::Ready(Ok(()))
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}
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}
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