Implement a golden testing model for tests

Cargo.lock

@@ -206,6 +206,7 @@ dependencies = [
  "logos",
  "pretty_assertions",
  "shrinkwraprs",
+ "walkdir",
 ]
 
 [[package]]
@@ -313,6 +314,15 @@ version = "0.6.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f162c6dd7b008981e4d40210aca20b4bd0f9b60ca9271061b07f78537722f2e1"
 
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "shrinkwraprs"
 version = "0.3.0"
@@ -391,6 +401,16 @@ version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
+[[package]]
+name = "walkdir"
+version = "2.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "36df944cda56c7d8d8b7496af378e6b16de9284591917d307c9b4d313c44e698"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
@@ -407,6 +427,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70ec6ce85bb158151cae5e5c87f95a8e97d2c0c4b001223f33a334e3ce5de178"
+dependencies = [
+ "winapi",
+]
+
 [[package]]
 name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"

Cargo.toml

@@ -14,3 +14,4 @@ shrinkwraprs = "0.3.0"
 
 [dev-dependencies]
 pretty_assertions = "1.4.0"
+walkdir = "2.3.3"

src/loader/mod.rs

@@ -1,5 +1,6 @@
 use crate::{ast::DefinitionBook, parser::parse_definition_book};
 use ariadne::{Color, Label, Report, ReportKind, Source};
+use chumsky::prelude::Rich;
 use std::path::Path;
 
 /// Reads a file and parses to a definition book.
@@ -8,18 +9,23 @@ pub fn load_file_to_book(path: &Path) -> anyhow::Result<DefinitionBook> {
   match parse_definition_book(&code) {
     Ok(book) => Ok(book),
     Err(errs) => {
-      for err in errs {
-        Report::build(ReportKind::Error, (), err.span().start)
-          .with_code(3)
-          .with_message(err.to_string())
-          .with_label(
-            Label::new(err.span().into_range()).with_message(err.reason().to_string()).with_color(Color::Red),
-          )
-          .finish()
-          .eprint(Source::from(code.clone()))
-          .unwrap();
-      }
+      print_err_reports(&path.to_string_lossy(), &code, errs);
       Err(anyhow::anyhow!("Parsing error"))
     }
   }
 }
+
+pub fn print_err_reports<'a, T: std::fmt::Display>(path: &str, code: &str, errs: Vec<Rich<T>>) {
+  errs.into_iter().for_each(|err| {
+    Report::build(ReportKind::Error, path, err.span().start)
+      .with_message(err.to_string())
+      .with_label(
+        Label::new((path, err.span().into_range()))
+          .with_message(err.reason().to_string())
+          .with_color(Color::Red),
+      )
+      .finish()
+      .eprint((path, Source::from(code.to_string())))
+      .unwrap()
+  })
+}

tests/golden_tests.rs

@@ -0,0 +1,42 @@
+use hvm_lang::{loader::print_err_reports, parser::parse_term, to_core::term_to_hvm_core};
+use pretty_assertions::assert_eq;
+use std::{collections::HashMap, fs, io::Write, path::Path};
+use walkdir::WalkDir;
+
+fn run_single_golden_test(path: &Path, run: &dyn Fn(&Path, &str) -> anyhow::Result<String>) -> anyhow::Result<()> {
+  let code = fs::read_to_string(path)?;
+  let result = run(path, &code)?;
+  let golden_path = path.with_extension("golden");
+  if let Ok(to_check) = fs::read_to_string(&golden_path) {
+    assert_eq!(result, to_check, "Testing file '{}'", path.display());
+    Ok(())
+  } else {
+    let mut file = fs::File::create(golden_path)?;
+    file.write_all(result.as_bytes())?;
+    Ok(())
+  }
+}
+
+fn run_golden_test_dir(root: &Path, run: &dyn Fn(&Path, &str) -> anyhow::Result<String>) {
+  for entry in WalkDir::new(root).follow_links(true) {
+    let entry = entry.unwrap();
+    let path = entry.path();
+    if path.is_file() && path.extension().map(|x| x == "hvm").unwrap_or(false) {
+      eprintln!("running {}", path.display());
+      run_single_golden_test(path, run).unwrap();
+    }
+  }
+}
+
+#[test]
+fn single_terms() {
+  let root = format!("{}/tests/golden_tests/single_terms", env!("CARGO_MANIFEST_DIR"));
+  run_golden_test_dir(Path::new(&root), &|path, code| {
+    let term = parse_term(code).map_err(|errs| {
+      print_err_reports(&path.to_string_lossy(), code, errs);
+      anyhow::anyhow!("Parsing error")
+    })?;
+    let net = term_to_hvm_core(&term, &HashMap::new())?;
+    Ok(net.to_string())
+  })
+}

tests/golden_tests/single_terms/church_one.hvm

@@ -0,0 +1 @@
+(λk λs λz dup s0 s1 = s; (s0 ((k s1) z))) (λq λw w)

tests/golden_tests/single_terms/church_zero.golden

@@ -0,0 +1 @@
+$ (0 * (0 x0 x0))

tests/golden_tests/single_terms/church_zero.hvm

@@ -0,0 +1 @@
+λs λz z

tests/golden_tests/single_terms/dup_apply.golden

@@ -0,0 +1 @@
+$ (0 (1 (0 x0 x1) x0) x1)

tests/golden_tests/single_terms/dup_apply.hvm

@@ -0,0 +1 @@
+λa dup a1 a2 = a; (a1 a2)

tests/golden_tests/single_terms/erased_dup.golden

@@ -0,0 +1 @@
+$ (0 (1 * x0) x0)

tests/golden_tests/single_terms/erased_dup.hvm

@@ -0,0 +1 @@
+λa dup a1 a2 = a; a2

tests/golden_tests/single_terms/id.golden

@@ -0,0 +1 @@
+$ (0 x0 x0)

tests/golden_tests/single_terms/id.hvm

@@ -0,0 +1 @@
+λa a