fix the chunk boundary (node:stream:createReadStream)

[Hanaasagi]

Close: #3668

What does this PR do?

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

Test Code:

const fs = require("node:fs");
const s = require("node:stream");

const path = "./test.txt";
fs.writeFileSync(path, "12345");

const stream = fs.createReadStream(path, { start: 0, end: 4 });

const writable = new s.Writable({
  write(chunk, encoding, callback) {
    console.log(chunk);
  },
});

stream.pipe(writable);

Checklist

If JavaScript/TypeScript modules or builtins changed:

• I ran make js and committed the transpiled changes
• I or my editor ran Prettier on the changed files (or I ran bun fmt)
• I included a test for the new code, or an existing test covers it

If Zig files changed:

• I checked the lifetime of memory allocated to verify it's (1) freed and (2) only freed when it should be
• I or my editor ran zig fmt on the changed files
• I included a test for the new code, or an existing test covers it
• JSValue used outside outside of the stack is either wrapped in a JSC.Strong or is JSValueProtect'ed

If new methods, getters, or setters were added to a publicly exposed class:

• I added TypeScript types for the new methods, getters, or setters

If dependencies in tests changed:

• I made sure that specific versions of dependencies are used instead of ranged or tagged versions

If functions were added to exports.zig or bindings.zig

• I ran make headers to regenerate the C header file

If *.classes.ts files were added or changed:

• I ran make codegen to regenerate the C++ and Zig code

If a new builtin ESM/CJS module was added:

• I updated Aliases in module_loader.zig to include the new module
• I added a test that imports the module
• I added a test that require() the module

[Jarred-Sumner]

i'm surprised there's an off-by-one error here but it also is consistent with the bug reports show.

you're sure it's not the += thing in http.write?

[Hanaasagi]

I need some time to test this issue, but at least this is not related to http.write. You can run this code, and compare the output with node.js.

const fs = require("node:fs");
const s = require("node:stream");

const path = "./test.txt";
fs.writeFileSync(path, "12345");

const stream = fs.createReadStream(path, { start: 0, end: 4 });

const writable = new s.Writable({
  write(chunk, encoding, callback) {
    console.log(chunk);
  },
});

stream.pipe(writable);

This won't execute any code related to http, just used stream.pip.

[Hanaasagi]

Hi, here's an explanation of why the createReadStream should be fixed.

As mentioned in issue #3668, the server-static package of express depends on send, which uses createReadStream to create read streams.

https://github.com/pillarjs/send/blob/b69cbb3dc4c09c37917d08a4c13fcd1bac97ade5/index.js#L691-L704
https://github.com/pillarjs/send/blob/b69cbb3dc4c09c37917d08a4c13fcd1bac97ade5/index.js#L777-L793

According to the Node.js documentation, end refers to the offset, not the size.

Link: https://nodejs.org/api/fs.html#fscreatereadstreampath-options

options can include start and end values to read a range of bytes from the file instead of the entire file. Both start and end are inclusive and start counting at 0, allowed values are in the [0, Number.MAX_SAFE_INTEGER] range.

[Jarred-Sumner]

Thank you