Add call of sdiff to main and basic integration test

Author: zxvfc

src/main.rs

@@ -18,6 +18,7 @@ mod ed_diff;
 mod macros;
 mod normal_diff;
 mod params;
+mod sdiff;
 mod side_diff;
 mod unified_diff;
 mod utils;
@@ -72,6 +73,7 @@ fn main() -> ExitCode {
     match util_name.to_str() {
         Some("diff") => diff::main(args),
         Some("cmp") => cmp::main(args),
+        Some("sdiff") => sdiff::main(args),
         Some(name) => {
             eprintln!("{name}: utility not supported");
             ExitCode::from(2)

tests/integration.rs

@@ -57,7 +57,7 @@ mod common {
         #[cfg(windows)]
         let error_message = "The system cannot find the file specified.";
 
-        for subcmd in ["diff", "cmp"] {
+        for subcmd in ["diff", "cmp", "sdiff"] {
             let mut cmd = cargo_bin_cmd!("diffutils");
             cmd.arg(subcmd);
             cmd.arg(&nopath).arg(file.path());
@@ -888,3 +888,27 @@ mod cmp {
         Ok(())
     }
 }
+
+mod sdiff {
+    use super::*;
+
+    #[test]
+    fn differences() -> Result<(), Box<dyn std::error::Error>> {
+        let mut file1 = NamedTempFile::new()?;
+        file1.write_all("foo\n".as_bytes())?;
+
+        let mut file2 = NamedTempFile::new()?;
+        file2.write_all("bar\n".as_bytes())?;
+
+        let mut cmd = cargo_bin_cmd!("diffutils");
+        cmd.arg("diff");
+        cmd.arg(file1.path()).arg(file2.path());
+
+        cmd.assert()
+            .code(predicate::eq(1))
+            .failure()
+            .stdout(predicate::str::is_empty().not());
+
+        Ok(())
+    }
+}