Implement sub-process based tester

1 files changed, 42 insertions, 11 deletions

diff --git a/rust/src/tester.rs b/rust/src/tester.rs
index 15ca468..019989b 100644
--- a/rust/src/tester.rs
+++ b/rust/src/tester.rs
@@ -1,15 +1,21 @@
 use std::{
-    fs,
-    path::{Path, PathBuf},
+    fs::{self, read_to_string, File},
+    path::PathBuf,
+    process::{Command, Stdio},
+    time::Instant,
 };
 
 pub fn main() {
-    let args: Vec<String> = std::env::args().collect();
+    let mut args: Vec<String> = std::env::args().collect();
+    // name of the process to run
+    let proc = args.remove(1);
     if args.len() > 1 {
         let run = traverse(&args)
-            .and_then(|paths| run_test(&paths))
+            .and_then(|paths| run_test(&proc, &paths))
             .expect("Failed to traverse directory");
         println!("{:?}", run)
+    } else {
+        println!("Usage: tester <process> <directory>+");
     }
 }
 
@@ -29,20 +35,26 @@ fn traverse(args: &[String]) -> Result<Vec<PathBuf>, String> {
 }
 
 #[derive(Debug)]
-struct TestRun {
+pub enum TestResult {
+    TestSucceeded,
+    TestFailed(String, String),
+}
+
+#[derive(Debug)]
+pub struct TestRun {
     file: String,
-    test_result: bool,
-    duration: u64,
+    test_result: TestResult,
+    duration: u128,
 }
 
-fn run_test(files: &Vec<PathBuf>) -> Result<Vec<TestRun>, String> {
+fn run_test(proc: &str, files: &Vec<PathBuf>) -> Result<Vec<TestRun>, String> {
     let mut result = Vec::new();
     for file in files {
         let mut inp = file.clone();
         let mut outp = file.clone();
         inp.push("input");
         outp.push("output");
-        let (test_result, duration) = run_test_case(&inp, &outp);
+        let (test_result, duration) = run_test_case(proc, &inp, &outp)?;
         result.push(TestRun {
             file: inp.as_path().to_str().unwrap().to_string(),
             test_result,
@@ -52,6 +64,25 @@ fn run_test(files: &Vec<PathBuf>) -> Result<Vec<TestRun>, String> {
     Ok(result)
 }
 
-fn run_test_case(inp: &std::path::PathBuf, outp: &std::path::PathBuf) -> (bool, u64) {
-    (true, 1)
+fn run_test_case(
+    proc: &str,
+    inp: &std::path::PathBuf,
+    outp: &std::path::PathBuf,
+) -> Result<(TestResult, u128), String> {
+    let input = File::open(inp).map_err(|e| e.to_string())?;
+    let expected = read_to_string(outp).map_err(|e| e.to_string())?;
+    let start = Instant::now();
+
+    let actual = Command::new(proc)
+        .stdin(Stdio::from(input))
+        .output()
+        .map_err(|e| e.to_string())?;
+
+    let duration = (Instant::now() - start).as_millis();
+    if expected.as_bytes() == actual.stdout {
+        Ok((TestResult::TestSucceeded, duration))
+    } else {
+        let actual_string = String::from_utf8(actual.stdout).map_err(|e| e.to_string())?;
+        Ok((TestResult::TestFailed(expected, actual_string), duration))
+    }
 }