Merge pull request #45 from oSoMoN/stdin-tests

Unit and integration tests for reading data from standard input

src/params.rs

@@ -457,6 +457,40 @@ mod tests {
         );
     }
     #[test]
+    fn default_to_stdin() {
+        assert_eq!(
+            Ok(Params {
+                from: os("foo"),
+                to: os("/dev/stdin"),
+                ..Default::default()
+            }),
+            parse_params([os("diff"), os("foo"), os("-")].iter().cloned())
+        );
+        assert_eq!(
+            Ok(Params {
+                from: os("/dev/stdin"),
+                to: os("bar"),
+                ..Default::default()
+            }),
+            parse_params([os("diff"), os("-"), os("bar")].iter().cloned())
+        );
+        assert_eq!(
+            Ok(Params {
+                from: os("/dev/stdin"),
+                to: os("/dev/stdin"),
+                ..Default::default()
+            }),
+            parse_params([os("diff"), os("-"), os("-")].iter().cloned())
+        );
+        assert!(parse_params([os("diff"), os("foo"), os("bar"), os("-")].iter().cloned()).is_err());
+        assert!(parse_params([os("diff"), os("-"), os("-"), os("-")].iter().cloned()).is_err());
+    }
+    #[test]
+    fn missing_arguments() {
+        assert!(parse_params([os("diff")].iter().cloned()).is_err());
+        assert!(parse_params([os("diff"), os("foo")].iter().cloned()).is_err());
+    }
+    #[test]
     fn unknown_argument() {
         assert!(
             parse_params([os("diff"), os("-g"), os("foo"), os("bar")].iter().cloned()).is_err()

tests/integration.rs

@@ -3,10 +3,9 @@
 // For the full copyright and license information, please view the LICENSE-*
 // files that was distributed with this source code.
 
-use assert_cmd::prelude::*;
+use assert_cmd::cmd::Command;
 use predicates::prelude::*;
 use std::io::Write;
-use std::process::Command;
 use tempfile::NamedTempFile;
 
 // Integration tests for the diffutils command
@@ -161,3 +160,46 @@ fn missing_newline() -> Result<(), Box<dyn std::error::Error>> {
         .stderr(predicate::str::starts_with("No newline at end of file"));
     Ok(())
 }
+
+#[test]
+fn read_from_stdin() -> 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 = Command::cargo_bin("diffutils")?;
+    cmd.arg("-u")
+        .arg(file1.path())
+        .arg("-")
+        .write_stdin("bar\n");
+    cmd.assert()
+        .code(predicate::eq(1))
+        .failure()
+        .stdout(predicate::eq(format!(
+            "--- {}\t\n+++ /dev/stdin\t\n@@ -1 +1 @@\n-foo\n+bar\n",
+            file1.path().to_string_lossy()
+        )));
+
+    let mut cmd = Command::cargo_bin("diffutils")?;
+    cmd.arg("-u")
+        .arg("-")
+        .arg(file2.path())
+        .write_stdin("foo\n");
+    cmd.assert()
+        .code(predicate::eq(1))
+        .failure()
+        .stdout(predicate::eq(format!(
+            "--- /dev/stdin\t\n+++ {}\t\n@@ -1 +1 @@\n-foo\n+bar\n",
+            file2.path().to_string_lossy()
+        )));
+
+    let mut cmd = Command::cargo_bin("diffutils")?;
+    cmd.arg("-u").arg("-").arg("-").write_stdin("foo\n");
+    cmd.assert()
+        .code(predicate::eq(0))
+        .success()
+        .stdout(predicate::str::is_empty());
+
+    Ok(())
+}