//! Node-ID generation — MUST produce byte-identical output to

//! `generateNodeId` in `src/extraction/tree-sitter-helpers.ts`:

//!

//! `${kind}:${sha256(`${filePath}:${kind}:${name}:${line}`).hex[0..32]}`

//!

//! and the file-node special case in `TreeSitterExtractor.extract()`:

//!

//! `file:${filePath}`

//!

//! Node identity is how the wasm path and the kernel path agree on the same

//! graph — a drift here breaks every edge. Pinned by the node-id parity test

//! in `__tests__/kernel-scaffold.test.ts`.

use sha2::{Digest, Sha256};

pub fn node_id(file_path: &str, kind: &str, name: &str, line: u32) -> String {

let mut hasher = Sha256::new();

hasher.update(file_path.as_bytes());

hasher.update(b":");

hasher.update(kind.as_bytes());

hasher.update(b":");

hasher.update(name.as_bytes());

hasher.update(b":");

hasher.update(line.to_string().as_bytes());

let digest = hasher.finalize();

// 32 hex chars = first 16 bytes.

let mut hex = String::with_capacity(kind.len() + 1 + 32);

hex.push_str(kind);

hex.push(':');

for b in &digest[..16] {

hex.push_str(&format!("{b:02x}"));

}

hex

}

pub fn file_node_id(file_path: &str) -> String {

format!("file:{file_path}")

}

#[cfg(test)]

mod tests {

use super::*;

#[test]

fn matches_known_ts_output() {

// Pinned vector: node -e "crypto.createHash('sha256')

// .update('src/a.ts:function:foo:3').digest('hex').substring(0,32)"

assert_eq!(

node_id("src/a.ts", "function", "foo", 3),

"function:bfb15544fed707794274a5c61006ea7b"

);

}

}