backhopper-core 0.37.0

// Copyright (C) 2026 Michael S. Klishin and Contributors
// SPDX-License-Identifier: Apache-2.0 OR MIT
// See LICENSE-APACHE and LICENSE-MIT for details.

use backhopper_core::compat::patch::{HunkLine, Patch, SourceKind};
use backhopper_core::errors::PatchError;

const SIMPLE_DIFF: &str = "\
diff --git a/src/ra_server.erl b/src/ra_server.erl
--- a/src/ra_server.erl
+++ b/src/ra_server.erl
@@ -1,3 +1,4 @@
-init() -> ok.
+init() -> ok.
+handle(X) -> ra_lib:id(X).
 % unchanged comment
";

#[test]
fn parses_a_minimal_unified_diff() {
    let p = Patch::parse(SIMPLE_DIFF.as_bytes()).unwrap();
    assert_eq!(p.files().len(), 1);
    assert_eq!(p.files()[0].language, SourceKind::Erlang);
    assert_eq!(p.files()[0].hunks.len(), 1);
}

#[test]
fn analyze_collects_referenced_calls() {
    let p = Patch::parse(SIMPLE_DIFF.as_bytes()).unwrap().analyze();
    let calls: Vec<String> = p
        .referenced()
        .iter()
        .filter_map(|sym| match &sym.kind {
            backhopper_core::SymbolKind::Function { mfa } => Some(mfa.to_string()),
            _ => None,
        })
        .collect();
    assert!(calls.iter().any(|c| c == "ra_lib:id/1"), "got {calls:?}");
}

#[test]
fn binary_diff_is_marked_binary() {
    let body = "\
diff --git a/x.bin b/x.bin
Binary files a/x.bin and b/x.bin differ
";
    let p = Patch::parse(body.as_bytes()).unwrap();
    assert!(p.files()[0].binary);
}

#[test]
fn rejects_oversized_input() {
    let huge = vec![b'a'; 65 * 1024 * 1024];
    let r = Patch::parse(&huge);
    assert!(r.is_err());
}

#[test]
fn rejects_invalid_utf8_with_offset() {
    let mut bytes = b"diff --git a/x b/x\n".to_vec();
    bytes.push(0xFF);
    match Patch::parse(&bytes) {
        Err(PatchError::InvalidUtf8 { offset }) => {
            assert_eq!(
                offset,
                bytes.len() - 1,
                "offset should point at the bad byte"
            );
        }
        other => panic!("expected InvalidUtf8, got {other:?}"),
    }
}

#[test]
fn captures_hunk_lines_whose_content_starts_with_dashes_or_pluses() {
    let body = "\
diff --git a/src/ra_log.erl b/src/ra_log.erl
--- a/src/ra_log.erl
+++ b/src/ra_log.erl
@@ -1,2 +1,2 @@
-    R = A -- B,
+    R = A ++ B,
";
    let p = Patch::parse(body.as_bytes()).unwrap();
    let lines = &p.files()[0].hunks[0].lines;
    let removed: Vec<&str> = lines
        .iter()
        .filter_map(|l| match l {
            HunkLine::Removed(s) => Some(s.as_str()),
            _ => None,
        })
        .collect();
    let added: Vec<&str> = lines
        .iter()
        .filter_map(|l| match l {
            HunkLine::Added(s) => Some(s.as_str()),
            _ => None,
        })
        .collect();
    assert_eq!(removed, vec!["    R = A -- B,"]);
    assert_eq!(added, vec!["    R = A ++ B,"]);
}

#[test]
fn dev_null_old_path_marks_an_added_file() {
    let body = "\
diff --git a/src/new.erl b/src/new.erl
--- /dev/null
+++ b/src/new.erl
@@ -0,0 +1,1 @@
+new_fun() -> ok.
";
    let p = Patch::parse(body.as_bytes()).unwrap();
    assert_eq!(p.files()[0].old_path, None);
    assert_eq!(
        p.files()[0].new_path.as_deref(),
        Some(std::path::Path::new("src/new.erl"))
    );
}