tests: init more scalable unit tests

Cargo.toml

@@ -6,16 +6,16 @@ license = "MIT"
 description = "Some functions to modify NixOS configuration files"
 repository = "https://github.com/vlinkz/nix-editor/"
 readme = "README.md"
-include = [
-  "src/*",
-  "Cargo.toml",
-  "LICENSE*",
-  "README.md",
-]
+include = ["src/*", "Cargo.toml", "LICENSE*", "README.md"]
 
 [dependencies]
-clap =  { version = "4.1", features = ["derive"] }
+clap = { version = "4.1", features = ["derive"] }
 rnix = "0.11"
 owo-colors = "3.5"
 thiserror = "1.0"
 nixpkgs-fmt = "1.3"
+
+[dev-dependencies]
+expect-test = "1.4.0"
+# serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"

src/lib.rs

@@ -1,5 +1,8 @@
 pub mod parse;
 pub mod read;
+#[cfg(test)]
+mod tests;
 pub mod write;
+
 #[cfg(test)]
-mod tests;
+mod unit_test;

src/unit_test.rs

@@ -0,0 +1,50 @@
+use crate::write::write;
+use expect_test::expect_file;
+use std::{ffi::OsStr, fs, path::PathBuf};
+
+fn dir_tests<F>(dir: &str, get_actual: F)
+where
+    F: Fn(String, Vec<String>) -> String,
+{
+    let base_path: PathBuf = [env!("CARGO_MANIFEST_DIR"), "test_data", dir]
+        .iter()
+        .collect();
+    let tests = base_path.read_dir().unwrap();
+    for test_case in tests {
+        let case_folder = test_case.unwrap().path();
+        let entries = base_path.join(&case_folder).read_dir().unwrap();
+
+        for entry in entries {
+            let path = entry.unwrap().path();
+
+            if path.extension() != Some(OsStr::new("nix")) {
+                continue;
+            }
+
+            println!("testing: {}", path.display());
+
+            let mut code = fs::read_to_string(&path).unwrap();
+            if code.ends_with('\n') {
+                code.truncate(code.len() - 1);
+            }
+            let args_path = path.with_extension("args");
+            let args_raw = fs::read_to_string(&args_path).unwrap();
+            let args: Vec<String> = serde_json::from_str(&args_raw).unwrap();
+
+            let actual = get_actual(code, args);
+            expect_file![path.with_extension("expect")].assert_eq(&actual);
+        }
+    }
+}
+
+#[test]
+fn write_dir_tests() {
+    dir_tests("write", |code: String, args| {
+        let actual = match write(&code, &args[0], &args[1]) {
+            Ok(s) => s,
+            Err(_) => panic!("Failed to write to file"),
+        };
+
+        actual
+    })
+}

test_data/write/attrs/empty_attrs.args

@@ -0,0 +1 @@
+["a","1"]

test_data/write/attrs/empty_attrs.expect

@@ -0,0 +1,3 @@
+{
+  a = 1;
+}

test_data/write/attrs/empty_attrs.nix

@@ -0,0 +1,2 @@
+{
+}

test_data/write/attrs/existing_attrs.args

@@ -0,0 +1 @@
+["a","1"]

test_data/write/attrs/existing_attrs.expect

@@ -0,0 +1,4 @@
+{
+  b = 2;
+  a = 1;
+}

test_data/write/attrs/existing_attrs.nix

@@ -0,0 +1,3 @@
+{
+  b = 2;
+}

test_data/write/attrs/nested_attrs.args

@@ -0,0 +1 @@
+["a.b","{}"]

test_data/write/attrs/nested_attrs.expect

@@ -0,0 +1,3 @@
+{
+  a.b = {};
+}

test_data/write/attrs/nested_attrs.nix

@@ -0,0 +1,2 @@
+{
+}

test_data/write/func/empty_func.args

@@ -0,0 +1 @@
+["a","1"]

test_data/write/func/empty_func.expect

@@ -0,0 +1,3 @@
+{lib, config, ...}:{
+  a = 1;
+}

test_data/write/func/empty_func.nix

@@ -0,0 +1,2 @@
+{lib, config, ...}:{
+}

test_data/write/let_in/let.args

@@ -0,0 +1 @@
+["a","1"]

test_data/write/let_in/let.expect

@@ -0,0 +1,5 @@
+let
+  res = {
+  a = 1;
+  };
+in res

test_data/write/let_in/let.nix

@@ -0,0 +1,4 @@
+let
+  res = {
+  };
+in res

test_data/write/values/int.args

@@ -0,0 +1 @@
+["a","1"]

test_data/write/values/int.expect

@@ -0,0 +1,3 @@
+{
+  a = 1;
+}

test_data/write/values/int.nix

@@ -0,0 +1,2 @@
+{
+}