fix: refactor samples to make running easier

samples/3np1.rpg.stdin

@@ -0,0 +1,2 @@
+8
+0

tests/samples.rs

@@ -1,17 +1,20 @@
-//! Integration tests — compile every `.rpg` sample and validate stdout
+//! Integration tests — compile every `.rpg` sample and validate stdout.
-//! against the accompanying `.rpg.golden` file.
 //!
-//! Each test follows the same three-step pipeline:
+//! Tests are discovered automatically: every file in `samples/` whose name
-//!   1. `rust-langrpg -o <tmp> <sample>.rpg`   — compile
+//! ends with `.rpg` becomes a test case.  Companion files control behaviour:
-//!   2. `<tmp>`                                  — execute (optionally with stdin)
+//!
-//!   3. compare stdout with `<sample>.rpg.golden`
+//! | file                  | purpose                                    |
+//! |-----------------------|--------------------------------------------|
+//! | `<name>.rpg.stdout`   | expected stdout (required to run the test) |
+//! | `<name>.rpg.stdin`    | bytes piped to stdin (optional)            |
 //!
 //! # Adding a new sample
 //!
-//! Drop the `.rpg` source and a `.rpg.golden` file into `samples/` and add a
+//! 1. Drop `samples/<name>.rpg` into the directory.
-//! `#[test]` that calls either:
+//! 2. Create `samples/<name>.rpg.stdout` with the expected output.
-//!   * `run_sample("your_file.rpg")`                    — no stdin input
+//! 3. Optionally create `samples/<name>.rpg.stdin` with any required input.
-//!   * `run_sample_stdin("your_file.rpg", b"input\n")`  — bytes fed to stdin
+//!
+//! No changes to this file are needed.
 
 use std::{
     fs,
@@ -27,50 +30,62 @@ const BIN: &str = env!("CARGO_BIN_EXE_rust-langrpg");
 const SAMPLES_DIR: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/samples");
 
 // ─────────────────────────────────────────────────────────────────────────────
-// Shared driver
+// Discovery
 // ─────────────────────────────────────────────────────────────────────────────
 
-/// Compile `sample_name` from `samples/`, run it with no stdin, and assert
+/// Returns a sorted list of `.rpg` file names found in `SAMPLES_DIR`.
-/// that its stdout matches `samples/<sample_name>.golden` line-for-line.
+fn discover_samples() -> Vec<String> {
-fn run_sample(sample_name: &str) {
+    let dir = fs::read_dir(SAMPLES_DIR)
-    run_sample_inner(sample_name, &[]);
+        .unwrap_or_else(|e| panic!("cannot read samples dir '{}': {e}", SAMPLES_DIR));
+
+    let mut names: Vec<String> = dir
+        .filter_map(|entry| {
+            let entry = entry.expect("dir entry error");
+            let name = entry.file_name().into_string().expect("non-UTF-8 filename");
+            if name.ends_with(".rpg") && !name.contains('.') == false {
+                // Accept only plain `<stem>.rpg` (no extra dots apart from the extension).
+                let stem = &name[..name.len() - 4]; // strip ".rpg"
+                if !stem.contains('.') {
+                    return Some(name);
+                }
+            }
+            None
+        })
+        .collect();
+
+    names.sort();
+    names
 }
 
-/// Like [`run_sample`] but feeds `stdin_bytes` to the program's standard input.
+// ─────────────────────────────────────────────────────────────────────────────
-///
+// Driver
-/// Use this for programs that read operator responses via the `DSPLY … response`
+// ─────────────────────────────────────────────────────────────────────────────
-/// opcode.  Pass every line the program will request, each terminated by `\n`.
+
-///
+/// Compile and run one sample, returning `Err(message)` on any failure.
-/// # Example
+fn run_one(sample_name: &str) -> Result<(), String> {
-///
+    let base = PathBuf::from(SAMPLES_DIR);
-/// ```no_run
+    let src = base.join(sample_name);
-/// run_sample_stdin("3np1.rpg", b"8\n0\n");
+    let stdout_path = base.join(format!("{}.stdout", sample_name));
-/// ```
+    let stdin_path = base.join(format!("{}.stdin", sample_name));
-fn run_sample_stdin(sample_name: &str, stdin_bytes: &[u8]) {
+
-    run_sample_inner(sample_name, stdin_bytes);
+    // Skip samples that have no golden file yet — they are works in progress.
+    if !stdout_path.exists() {
+        return Err(format!(
+            "SKIP '{}': no expected-output file '{}'",
+            sample_name,
+            stdout_path.display(),
+        ));
     }
 
-/// Internal driver shared by [`run_sample`] and [`run_sample_stdin`].
+    let stdin_bytes: Vec<u8> = if stdin_path.exists() {
-fn run_sample_inner(sample_name: &str, stdin_bytes: &[u8]) {
+        fs::read(&stdin_path)
-    let src = PathBuf::from(SAMPLES_DIR).join(sample_name);
+            .map_err(|e| format!("cannot read stdin file '{}': {e}", stdin_path.display()))?
-    let golden_path = PathBuf::from(SAMPLES_DIR).join(format!("{}.golden", sample_name));
+    } else {
-
+        Vec::new()
-    assert!(
+    };
-        src.exists(),
-        "source file not found: {}",
-        src.display()
-    );
-    assert!(
-        golden_path.exists(),
-        "golden file not found: {}\n\
-         Create it with the expected stdout to enable this test.",
-        golden_path.display()
-    );
 
     // ── 1. Compile ────────────────────────────────────────────────────────────
 
-    // Sanitise the name so it is safe to use in a file path (e.g. "for.rpg"
-    // becomes "for_rpg") and prefix so artefacts are easy to identify.
     let safe_stem = sample_name
         .replace('.', "_")
         .replace(std::path::MAIN_SEPARATOR, "_");
@@ -79,72 +94,70 @@ fn run_sample_inner(sample_name: &str, stdin_bytes: &[u8]) {
     let compile_out = Command::new(BIN)
         .args(["-o", exe.to_str().unwrap(), src.to_str().unwrap()])
         .output()
-        .unwrap_or_else(|e| panic!("failed to spawn compiler for '{}': {e}", sample_name));
+        .map_err(|e| format!("failed to spawn compiler for '{}': {e}", sample_name))?;
 
-    assert!(
+    if !compile_out.status.success() {
-        compile_out.status.success(),
+        return Err(format!(
             "compilation of '{}' failed (exit {})\nstderr:\n{}",
             sample_name,
             compile_out.status,
             String::from_utf8_lossy(&compile_out.stderr),
-    );
+        ));
+    }
 
-    assert!(
+    if !exe.exists() {
-        exe.exists(),
+        return Err(format!(
-        "compiler exited 0 for '{}' but no executable was produced at '{}'",
+            "compiler exited 0 for '{}' but produced no executable at '{}'",
             sample_name,
             exe.display(),
-    );
+        ));
+    }
 
     // ── 2. Execute ────────────────────────────────────────────────────────────
 
     let run_out = if stdin_bytes.is_empty() {
-        // No input needed — let stdin inherit /dev/null so the process never
-        // blocks waiting for a read that will never come.
         Command::new(&exe)
             .stdin(Stdio::null())
             .output()
-            .unwrap_or_else(|e| panic!("failed to run '{}': {e}", sample_name))
+            .map_err(|e| format!("failed to run '{}': {e}", sample_name))?
     } else {
-        // Pipe the provided bytes to the program's stdin.
         let mut child = Command::new(&exe)
             .stdin(Stdio::piped())
             .stdout(Stdio::piped())
             .stderr(Stdio::piped())
             .spawn()
-            .unwrap_or_else(|e| panic!("failed to spawn '{}': {e}", sample_name));
+            .map_err(|e| format!("failed to spawn '{}': {e}", sample_name))?;
 
-        // Write all input at once; the programs we test read only a handful of
-        // lines so this never fills the OS pipe buffer.
         child
             .stdin
             .take()
             .expect("stdin was piped")
-            .write_all(stdin_bytes)
+            .write_all(&stdin_bytes)
-            .unwrap_or_else(|e| panic!("failed to write stdin for '{}': {e}", sample_name));
+            .map_err(|e| format!("failed to write stdin for '{}': {e}", sample_name))?;
 
         child
             .wait_with_output()
-            .unwrap_or_else(|e| panic!("failed to wait on '{}': {e}", sample_name))
+            .map_err(|e| format!("failed to wait on '{}': {e}", sample_name))?
     };
 
-    assert!(
+    if !run_out.status.success() {
-        run_out.status.success(),
+        return Err(format!(
             "binary for '{}' exited non-zero ({})\nstdout:\n{}\nstderr:\n{}",
             sample_name,
             run_out.status,
             String::from_utf8_lossy(&run_out.stdout),
             String::from_utf8_lossy(&run_out.stderr),
-    );
+        ));
+    }
 
-    // ── 3. Compare against golden ─────────────────────────────────────────────
+    // ── 3. Compare against expected output ───────────────────────────────────
 
     let actual_raw = String::from_utf8_lossy(&run_out.stdout);
-    let expected_raw = fs::read_to_string(&golden_path)
+    let expected_raw = fs::read_to_string(&stdout_path)
-        .unwrap_or_else(|e| panic!("could not read golden '{}': {e}", golden_path.display()));
+        .map_err(|e| format!("could not read '{}': {e}", stdout_path.display()))?;
 
-    // Normalise both sides: trim trailing whitespace per line and ignore a
+    // Trim trailing whitespace per line; ignore a lone trailing blank line so
-    // lone trailing blank line so golden files don't need a precise final newline.
+    // `.rpg.stdout` files don't need a precise final newline.
     let normalise = |s: &str| -> Vec<String> {
         let mut lines: Vec<String> = s.lines().map(|l| l.trim_end().to_string()).collect();
         if lines.last().map(|l| l.is_empty()).unwrap_or(false) {
@@ -157,7 +170,7 @@ fn run_sample_inner(sample_name: &str, stdin_bytes: &[u8]) {
     let expected_lines = normalise(&expected_raw);
 
     if actual_lines == expected_lines {
-        return;
+        return Ok(());
     }
 
     // ── Build a readable diff-style failure message ───────────────────────────
@@ -185,7 +198,6 @@ fn run_sample_inner(sample_name: &str, stdin_bytes: &[u8]) {
         msg.push('\n');
     }
 
-    // Point at the first diverging line to make the failure easy to locate.
     for (i, (exp, act)) in expected_lines.iter().zip(actual_lines.iter()).enumerate() {
         if exp != act {
             msg.push_str(&format!(
@@ -205,37 +217,60 @@ fn run_sample_inner(sample_name: &str, stdin_bytes: &[u8]) {
         ));
     }
 
-    panic!("{}", msg);
+    Err(msg)
 }
 
 // ─────────────────────────────────────────────────────────────────────────────
-// One #[test] per sample
+// Single test entry-point
 // ─────────────────────────────────────────────────────────────────────────────
 
 #[test]
-fn sample_hello() {
+fn samples() {
-    run_sample("hello.rpg");
+    let names = discover_samples();
+
+    assert!(
+        !names.is_empty(),
+        "no .rpg files found in '{}'",
+        SAMPLES_DIR,
+    );
+
+    let mut failures: Vec<String> = Vec::new();
+    let mut skipped: Vec<String> = Vec::new();
+
+    for name in &names {
+        eprint!("  sample '{}' … ", name);
+        match run_one(name) {
+            Ok(()) => eprintln!("ok"),
+            Err(msg) if msg.starts_with("SKIP") => {
+                eprintln!("skipped");
+                skipped.push(msg);
+            }
+            Err(msg) => {
+                eprintln!("FAILED");
+                failures.push(msg);
+            }
+        }
     }
 
-#[test]
+    if !skipped.is_empty() {
-fn sample_for() {
+        eprintln!("\n{} sample(s) skipped (no .rpg.stdout file):", skipped.len());
-    run_sample("for.rpg");
+        for s in &skipped {
+            eprintln!("  {}", s);
+        }
     }
 
-#[test]
+    if failures.is_empty() {
-fn sample_fib() {
+        return;
-    run_sample("fib.rpg");
     }
 
-#[test]
+    let mut report = format!(
-fn sample_fizzbuzz() {
+        "\n{} of {} sample(s) failed:\n",
-    run_sample("fizzbuzz.rpg");
+        failures.len(),
+        names.len(),
+    );
+    for (i, f) in failures.iter().enumerate() {
+        report.push_str(&format!("\n── failure {} ──────────────────────────────────────────\n{}\n", i + 1, f));
     }
 
-#[test]
+    panic!("{}", report);
-fn sample_3np1() {
-    // Test the Collatz (3n+1) program with a starting value of 8.
-    // The sequence 8 → 4 → 2 → 1 takes 3 steps.
-    // A second input of 0 tells the outer loop to exit.
-    run_sample_stdin("3np1.rpg", b"8\n0\n");
 }