http-body 1.1.0: http_body

# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
version = 4

[[package]]
name = "bytes"
version = "1.12.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "fc652a48c352aef3ea3aed32080501cf3ef6ed5da78602a020c991775b0aff04"

[[package]]
name = "http"
version = "1.5.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "918d3568bebf352712bc2ef3d46a8bcf1a75b373be6539de198e9105cbbf9ce0"
dependencies = [
 "bytes",
 "itoa",
]

[[package]]
name = "http-body"
version = "1.1.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "ca2a8f2913ee65f60facd6a5905613afaa448497a0230cc41ce022d93290bc2c"
dependencies = [
 "bytes",
 "http",
]

[[package]]
name = "itoa"
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checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"

[[package]]
name = "sample-http-body"
version = "1.0.0"
dependencies = [
 "http-body",
]

[package]
name = "sample-http-body"
version = "1.0.0"
edition = "2021"
publish = false

[dependencies]
http-body = "=1.1.0"

[[bin]]
name = "contract"
path = "test/contract.rs"

Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify http_body in pkg:cargo/http-body@1.1.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:cargo/http-body@1.1.0
Demonstrate these symbols/APIs:
  - http_body

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.

{"case":{"caseId":"case:sha256:d9fd86a5b61a49aba9b60eb93418d5150858324109b63a1a53b72f0280c6c4b6","contract":["Frame::data creates a data frame holding a byte buffer with data flags","Frame::map_data transforms the buffer in a data frame","SizeHint tracks lower and upper bounds and exact size","SizeHint addition combines bounds from two hints","Custom types implement Body to stream frames","String implements Body yielding a data frame and reporting exact size"],"goal":"verify http_body in pkg:cargo/http-body@1.1.0","kind":"HOW","packages":["pkg:cargo/http-body@1.1.0"],"schemaVersion":1,"symbols":["http_body"]},"contractCommand":["cargo","run","--offline"],"environment":{"arch":"x64","distro":"alpine","ecosystem":"cargo","libc":"musl","os":"linux","packageManager":"cargo","schemaVersion":1},"license":"MIT-0","packages":["pkg:cargo/http-body@1.1.0"],"schemaVersion":1,"subject":"pkg:cargo/http-body@1.1.0","symbols":["http_body"],"verifierAdapter":"cargo@1"}

{
  "schemaVersion": 1,
  "goal": "verify http_body in pkg:cargo/http-body@1.1.0",
  "kind": "HOW",
  "packages": [
    "pkg:cargo/http-body@1.1.0"
  ],
  "symbols": [
    "http_body"
  ]
}

//! Clean-room verification sample for http-body.

pub use http_body::*;

use http_body::{Body, Frame, SizeHint};
use std::convert::Infallible;
use std::pin::Pin;
use std::task::{Context, Poll, RawWaker, RawWakerVTable, Waker};

fn noop_waker() -> Waker {
    const VTABLE: RawWakerVTable = RawWakerVTable::new(
        |_| RawWaker::new(std::ptr::null(), &VTABLE),
        |_| {},
        |_| {},
        |_| {},
    );
    unsafe { Waker::from_raw(RawWaker::new(std::ptr::null(), &VTABLE)) }
}

struct StaticBody {
    data: Option<&'static [u8]>,
}

impl Body for StaticBody {
    type Data = &'static [u8];
    type Error = Infallible;

    fn poll_frame(
        mut self: Pin<&mut Self>,
        _cx: &mut Context<'_>,
    ) -> Poll<Option<Result<Frame<Self::Data>, Self::Error>>> {
        if let Some(data) = self.data.take() {
            Poll::Ready(Some(Ok(Frame::data(data))))
        } else {
            Poll::Ready(None)
        }
    }

    fn is_end_stream(&self) -> bool {
        self.data.is_none()
    }

    fn size_hint(&self) -> SizeHint {
        match self.data {
            Some(data) => SizeHint::with_exact(data.len() as u64),
            None => SizeHint::with_exact(0),
        }
    }
}

fn main() {
    let waker = noop_waker();
    let mut cx = Context::from_waker(&waker);

    // 1. Frame::data creates a data frame holding a byte buffer with data flags
    let mut frame = Frame::data(&b"stream payload"[..]);
    assert!(frame.is_data());
    assert!(!frame.is_trailers());
    assert_eq!(frame.data_ref(), Some(&&b"stream payload"[..]));
    assert_eq!(frame.data_mut(), Some(&mut &b"stream payload"[..]));
    let data = frame.into_data().expect("expected data payload");
    assert_eq!(data, b"stream payload");

    // 2. Frame::map_data transforms the buffer in a data frame
    let frame = Frame::data(&b"abc"[..]);
    let mapped = frame.map_data(|bytes| bytes.len());
    assert_eq!(mapped.into_data().expect("expected mapped data"), 3);

    // 3. SizeHint tracks lower and upper bounds and exact size
    let mut hint = SizeHint::new();
    assert_eq!(hint.lower(), 0);
    assert_eq!(hint.upper(), None);
    assert_eq!(hint.exact(), None);
    hint.set_lower(10);
    hint.set_upper(20);
    assert_eq!(hint.lower(), 10);
    assert_eq!(hint.upper(), Some(20));
    assert_eq!(hint.exact(), None);
    hint.set_exact(15);
    assert_eq!(hint.lower(), 15);
    assert_eq!(hint.upper(), Some(15));
    assert_eq!(hint.exact(), Some(15));

    // 4. SizeHint addition combines bounds from two hints
    let h1 = SizeHint::with_exact(100);
    let h2 = SizeHint::with_exact(250);
    let combined = h1 + h2;
    assert_eq!(combined.exact(), Some(350));

    // 5. Custom types implement Body to stream frames
    let mut custom_body = StaticBody {
        data: Some(b"custom frame data"),
    };
    assert_eq!(custom_body.size_hint().exact(), Some(17));
    assert!(!custom_body.is_end_stream());

    let mut pinned = Pin::new(&mut custom_body);
    let first_poll = pinned.as_mut().poll_frame(&mut cx);
    match first_poll {
        Poll::Ready(Some(Ok(f))) => {
            assert!(f.is_data());
            assert_eq!(f.into_data().unwrap(), b"custom frame data");
        }
        _ => panic!("expected successful frame from custom body"),
    }
    assert!(pinned.is_end_stream());
    let second_poll = pinned.as_mut().poll_frame(&mut cx);
    assert!(matches!(second_poll, Poll::Ready(None)));

    // 6. String implements Body yielding a data frame and reporting exact size
    let mut string_body = String::from("hello http_body");
    assert_eq!(string_body.size_hint().exact(), Some(15));
    assert!(!string_body.is_end_stream());

    let mut pinned_str = Pin::new(&mut string_body);
    let poll_str = pinned_str.as_mut().poll_frame(&mut cx);
    match poll_str {
        Poll::Ready(Some(Ok(f))) => {
            assert!(f.is_data());
            assert_eq!(f.into_data().unwrap().as_ref(), b"hello http_body");
        }
        _ => panic!("expected frame from String body"),
    }
    assert!(pinned_str.is_end_stream());
    let poll_str_end = pinned_str.as_mut().poll_frame(&mut cx);
    assert!(matches!(poll_str_end, Poll::Ready(None)));

    println!("All http_body contract assertions passed successfully.");
}