mirror of
https://github.com/vercel-labs/scriptc.git
synced 2026-11-03 07:54:40 +08:00
Chris Tate
c6679d43fb
push() of an empty Buffer outside object mode put a zero-length entry into the read buffer, and the chunks pushed after it stalled behind it: a 'data' listener saw nothing more and a readline interface never closed. Node's readableAddChunk adds no empty chunk outside object mode; it clears the reading flag and may read more. The runtime now does the same, as it already did for an encoded push that decodes to nothing.
70 lines
2.1 KiB
TypeScript
70 lines
2.1 KiB
TypeScript
// readable.push() of an empty Buffer outside object mode adds nothing, as
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// in Node: the chunks pushed after it still reach 'data' listeners,
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// readline and read(), and push(null) still ends the stream. In object
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// mode an empty Buffer is a value like any other.
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import { createInterface } from "node:readline";
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import { Readable } from "node:stream";
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function lines(chunks: string[]): Promise<void> {
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return new Promise<void>((resolve) => {
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const src = new Readable({ read() {} });
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const rl = createInterface({ input: src, crlfDelay: Infinity });
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rl.on("line", (line: string) => console.log("line", JSON.stringify(line)));
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rl.on("close", () => {
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console.log("readline closed");
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resolve();
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});
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for (const chunk of chunks) src.push(Buffer.from(chunk, "utf8"));
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src.push(null);
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});
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}
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function data(): Promise<void> {
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return new Promise<void>((resolve) => {
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const src = new Readable({ read() {} });
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src.on("data", (chunk: Buffer) => console.log("data", JSON.stringify(String(chunk))));
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src.on("end", () => {
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console.log("data end");
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resolve();
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});
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console.log("push a", src.push(Buffer.from("a")));
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console.log("push empty", src.push(Buffer.alloc(0)));
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console.log("push b", src.push(Buffer.from("b")));
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src.push(null);
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});
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}
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function paused(): void {
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const src = new Readable({ read() {} });
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src.push(Buffer.from("x"));
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src.push(Buffer.alloc(0));
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src.push(Buffer.from("y"));
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console.log("readableLength", src.readableLength);
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console.log("read", JSON.stringify(String(src.read())));
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}
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function objectMode(): Promise<void> {
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return new Promise<void>((resolve) => {
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const src = new Readable({ objectMode: true, read() {} });
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src.on("data", (chunk: Buffer) => console.log("object chunk length", chunk.length));
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src.on("end", () => {
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console.log("object end");
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resolve();
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});
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src.push(Buffer.alloc(0));
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src.push(Buffer.from("z"));
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src.push(null);
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});
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}
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async function main(): Promise<void> {
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await lines(["a\nb", "", "c\n"]);
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await lines(["", "", "only\n"]);
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await data();
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paused();
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await objectMode();
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console.log("done");
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}
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main();
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