test: smoke-test the README in-house contract demo end-to-end (Move #4)

Author: logannye

tests/frontdoor_demo.rs

@@ -0,0 +1,92 @@
+//! Proves the README's in-house contract demo actually runs end-to-end on the
+//! bundled single-contig fixture: index → sort → plan → variants --enforce → verify.
+
+use std::path::PathBuf;
+use std::process::Command;
+use std::sync::atomic::{AtomicU64, Ordering};
+
+fn bin() -> &'static str {
+    env!("CARGO_BIN_EXE_rosalind")
+}
+
+fn unique_dir() -> PathBuf {
+    static C: AtomicU64 = AtomicU64::new(0);
+    let n = C.fetch_add(1, Ordering::Relaxed);
+    let nanos = std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .unwrap()
+        .as_nanos();
+    let d = std::env::temp_dir().join(format!("rosalind-frontdoor-{nanos}-{n}"));
+    std::fs::create_dir_all(&d).unwrap();
+    d
+}
+
+fn run(args: &[&str]) -> std::process::Output {
+    Command::new(bin())
+        .args(args)
+        .output()
+        .expect("spawn rosalind")
+}
+
+#[test]
+fn readme_inhouse_contract_demo_runs_end_to_end() {
+    // CARGO_MANIFEST_DIR points at the crate root; the fixture is bundled there.
+    let root = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    let fa = root.join("examples/data/illumina_toy/reference.fa");
+    let bam = root.join("examples/data/illumina_toy/alignments.bam");
+    assert!(fa.exists(), "bundled reference missing: {}", fa.display());
+    assert!(bam.exists(), "bundled alignments missing: {}", bam.display());
+
+    let dir = unique_dir();
+    let idx = dir.join("toy.idx");
+    let sorted = dir.join("toy.sorted.bam");
+    let vcf = dir.join("toy.vcf");
+    let manifest = dir.join("toy.vcf.manifest.json");
+
+    let out = run(&[
+        "index",
+        "--reference",
+        fa.to_str().unwrap(),
+        "--output",
+        idx.to_str().unwrap(),
+    ]);
+    assert!(out.status.success(), "index: {}", String::from_utf8_lossy(&out.stderr));
+
+    let out = run(&[
+        "sort",
+        "--input",
+        bam.to_str().unwrap(),
+        "--output",
+        sorted.to_str().unwrap(),
+    ]);
+    assert!(out.status.success(), "sort: {}", String::from_utf8_lossy(&out.stderr));
+
+    let out = run(&["plan", "--index", idx.to_str().unwrap(), "--budget-mb", "512"]);
+    assert!(out.status.success(), "plan: {}", String::from_utf8_lossy(&out.stderr));
+    assert!(String::from_utf8_lossy(&out.stdout).contains("predicted peak"));
+
+    let out = run(&[
+        "variants",
+        "--index",
+        idx.to_str().unwrap(),
+        "--alignments",
+        sorted.to_str().unwrap(),
+        "--memory-budget-mb",
+        "512",
+        "--enforce",
+        "-o",
+        vcf.to_str().unwrap(),
+    ]);
+    assert!(
+        out.status.success(),
+        "variants --enforce: {}",
+        String::from_utf8_lossy(&out.stderr)
+    );
+    assert!(manifest.exists(), "receipt sidecar must be written");
+
+    let out = run(&["verify", "--manifest", manifest.to_str().unwrap()]);
+    assert!(out.status.success(), "verify: {}", String::from_utf8_lossy(&out.stderr));
+    assert!(String::from_utf8_lossy(&out.stdout).contains("verify: OK"));
+
+    std::fs::remove_dir_all(&dir).ok();
+}