chore: codegen formatter test cases (#3006)

tooling/nargo_fmt/build.rs

@@ -0,0 +1,68 @@
+use std::fs::File;
+use std::io::Write;
+use std::path::{Path, PathBuf};
+use std::{env, fs};
+
+fn main() {
+    let out_dir = env::var("OUT_DIR").unwrap();
+    let destination = Path::new(&out_dir).join("execute.rs");
+    let mut test_file = File::create(destination).unwrap();
+
+    // Try to find the directory that Cargo sets when it is running; otherwise fallback to assuming the CWD
+    // is the root of the repository and append the crate path
+    let manifest_dir = match std::env::var("CARGO_MANIFEST_DIR") {
+        Ok(dir) => PathBuf::from(dir),
+        Err(_) => std::env::current_dir().unwrap().join("crates").join("nargo_cli"),
+    };
+    let test_dir = manifest_dir.join("tests");
+
+    generate_formatter_tests(&mut test_file, &test_dir);
+}
+
+fn generate_formatter_tests(test_file: &mut File, test_data_dir: &Path) {
+    let inputs_dir = test_data_dir.join("input");
+    let outputs_dir = test_data_dir.join("expected");
+
+    let test_case_files =
+        fs::read_dir(inputs_dir).unwrap().flatten().filter(|c| c.path().is_file());
+
+    for file in test_case_files {
+        let file_path = file.path();
+        let file_name = file_path.file_name().unwrap();
+        let test_name = file_path.file_stem().unwrap().to_str().unwrap();
+
+        if test_name.contains('-') {
+            panic!(
+                "Invalid test directory: {test_name}. Cannot include `-`, please convert to `_`"
+            );
+        };
+
+        let input_source_path = file.path();
+        let input_source = std::fs::read_to_string(input_source_path).unwrap();
+
+        let output_source_path = outputs_dir.join(file_name);
+        let output_source = std::fs::read_to_string(output_source_path).unwrap();
+
+        write!(
+            test_file,
+            r##"
+#[test]
+fn format_{test_name}() {{
+    let input = r#"{input_source}"#;
+    let expected_output = r#"{output_source}"#;
+
+
+    let (parsed_module, errors) = noirc_frontend::parse_program(&input);
+    assert!(errors.is_empty());
+
+    let config = nargo_fmt::Config::default();
+    let fmt_text = nargo_fmt::format(&input, parsed_module, &config);
+
+
+    assert_eq!(fmt_text, expected_output);
+}}
+            "##
+        )
+        .expect("Could not write templated test file.");
+    }
+}

tooling/nargo_fmt/src/lib.rs

@@ -33,51 +33,3 @@ pub fn format(source: &str, parsed_module: ParsedModule, config: &Config) -> Str
     fmt.visit_module(parsed_module);
     fmt.finish()
 }
-
-#[cfg(test)]
-mod tests {
-    use std::{ffi::OsStr, path::PathBuf};
-
-    use crate::Config;
-
-    #[test]
-    fn test() {
-        let files = std::fs::read_dir("tests/input").unwrap();
-        for file in files {
-            let file = file.unwrap();
-
-            let config = Config::default();
-
-            let source_path = file.path();
-            let source = std::fs::read_to_string(&source_path).unwrap();
-
-            let (parsed_module, errors) = noirc_frontend::parse_program(&source);
-            let fmt_text = crate::format(&source, parsed_module, &config);
-
-            assert!(errors.is_empty());
-
-            let target_path: PathBuf = source_path
-                .components()
-                .map(|component| {
-                    if component.as_os_str() == "input" {
-                        OsStr::new("expected")
-                    } else {
-                        component.as_os_str()
-                    }
-                })
-                .collect();
-
-            let target = match std::fs::read_to_string(&target_path) {
-                Ok(t) => t,
-                Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
-                    std::fs::write(target_path, fmt_text.clone()).unwrap();
-                    fmt_text.clone()
-                }
-                Err(err) => unreachable!("{err}"),
-            };
-
-            // FIXME: better diff
-            assert_eq!(fmt_text, target);
-        }
-    }
-}

tooling/nargo_fmt/tests/execute.rs

@@ -0,0 +1,5 @@
+#[cfg(test)]
+mod tests {
+    // include tests generated by `build.rs`
+    include!(concat!(env!("OUT_DIR"), "/execute.rs"));
+}