Add integration tests.

tests/workdir.rs

@@ -0,0 +1,189 @@
+use std::env;
+use std::error;
+use std::fmt;
+use std::fs::{self, File};
+use std::io::{self, Write};
+use std::path::{Path, PathBuf};
+use std::process;
+use std::str::FromStr;
+use std::sync::atomic::{ATOMIC_USIZE_INIT, AtomicUsize, Ordering};
+use std::thread;
+use std::time::Duration;
+
+static TEST_DIR: &'static str = "ripgrep-tests";
+static NEXT_ID: AtomicUsize = ATOMIC_USIZE_INIT;
+
+/// WorkDir represents a directory in which tests are run.
+///
+/// Directories are created from a global atomic counter to avoid duplicates.
+#[derive(Debug)]
+pub struct WorkDir {
+    /// The directory in which this test executable is running.
+    root: PathBuf,
+    /// The directory in which the test should run. If a test needs to create
+    /// files, they should go in here.
+    dir: PathBuf,
+}
+
+impl WorkDir {
+    /// Create a new test working directory with the given name. The name
+    /// does not need to be distinct for each invocation, but should correspond
+    /// to a logical grouping of tests.
+    pub fn new(name: &str) -> WorkDir {
+        let id = NEXT_ID.fetch_add(1, Ordering::SeqCst);
+        let root = env::current_exe().unwrap()
+            .parent().expect("executable's directory").to_path_buf();
+        let dir = root.join(TEST_DIR).join(name).join(&format!("{}", id));
+        nice_err(&dir, repeat(|| fs::create_dir_all(&dir)));
+        WorkDir {
+            root: root,
+            dir: dir,
+        }
+    }
+
+    /// Create a new file with the given name and contents in this directory.
+    pub fn create<P: AsRef<Path>>(&self, name: P, contents: &str) {
+        let path = self.dir.join(name);
+        let mut file = nice_err(&path, File::create(&path));
+        nice_err(&path, file.write_all(contents.as_bytes()));
+        nice_err(&path, file.flush());
+    }
+
+    /// Remove a file with the given name from this directory.
+    pub fn remove<P: AsRef<Path>>(&self, name: P) {
+        let path = self.dir.join(name);
+        nice_err(&path, fs::remove_file(&path));
+    }
+
+    /// Create a new directory with the given path (and any directories above
+    /// it) inside this directory.
+    pub fn create_dir<P: AsRef<Path>>(&self, path: P) {
+        let path = self.dir.join(path);
+        nice_err(&path, repeat(|| fs::create_dir_all(&path)));
+    }
+
+    /// Creates a new command that is set to use the ripgrep executable in
+    /// this working directory.
+    pub fn command(&self) -> process::Command {
+        let mut cmd = process::Command::new(&self.bin());
+        cmd.current_dir(&self.dir);
+        cmd
+    }
+
+    /// Returns the path to the ripgrep executable.
+    pub fn bin(&self) -> PathBuf {
+        self.root.join("rg")
+    }
+
+    /// Returns the path to this directory.
+    pub fn path(&self) -> &Path {
+        &self.dir
+    }
+
+    /// Creates a directory symlink to the src with the given target name
+    /// in this directory.
+    #[cfg(not(windows))]
+    pub fn link<S: AsRef<Path>, T: AsRef<Path>>(&self, src: S, target: T) {
+        use std::os::unix::fs::symlink;
+        let src = self.dir.join(src);
+        let target = self.dir.join(target);
+        let _ = fs::remove_file(&target);
+        nice_err(&target, symlink(&src, &target));
+    }
+
+    #[cfg(windows)]
+    pub fn link<S: AsRef<Path>, T: AsRef<Path>>(&self, src: S, target: T) {
+        use std::os::windows::fs::symlink_dir;
+        let src = self.dir.join(src);
+        let target = self.dir.join(target);
+        let _ = fs::remove_dir(&target);
+        nice_err(&target, symlink_dir(&src, &target));
+    }
+
+    /// Runs and captures the stdout of the given command.
+    ///
+    /// If the return type could not be created from a string, then this
+    /// panics.
+    pub fn stdout<E: fmt::Debug, T: FromStr<Err=E>>(
+        &self,
+        cmd: &mut process::Command,
+    ) -> T {
+        let o = self.output(cmd);
+        let stdout = String::from_utf8_lossy(&o.stdout);
+        match stdout.parse() {
+            Ok(t) => t,
+            Err(err) => {
+                panic!("could not convert from string: {:?}\n\n{}", err, stdout);
+            }
+        }
+    }
+
+    /// Gets the output of a command. If the command failed, then this panics.
+    pub fn output(&self, cmd: &mut process::Command) -> process::Output {
+        let o = cmd.output().unwrap();
+        if !o.status.success() {
+            let suggest =
+                if o.stderr.is_empty() {
+                    "\n\nDid your search end up with no results?".to_string()
+                } else {
+                    "".to_string()
+                };
+
+            panic!("\n\n==========\n\
+                    command failed but expected success!\
+                    {}\
+                    \n\ncommand: {:?}\
+                    \ncwd: {}\
+                    \n\nstatus: {}\
+                    \n\nstdout: {}\
+                    \n\nstderr: {}\
+                    \n\n==========\n",
+                   suggest, cmd, self.dir.display(), o.status,
+                   String::from_utf8_lossy(&o.stdout),
+                   String::from_utf8_lossy(&o.stderr));
+        }
+        o
+    }
+
+    /// Runs the given command and asserts that it resulted in an error exit
+    /// code.
+    pub fn assert_err(&self, cmd: &mut process::Command) {
+        let o = cmd.output().unwrap();
+        if o.status.success() {
+            panic!("\n\n===== {:?} =====\n\
+                    command succeeded but expected failure!\
+                    \n\ncwd: {}\
+                    \n\nstatus: {}\
+                    \n\nstdout: {}\n\nstderr: {}\
+                    \n\n=====\n",
+                   cmd, self.dir.display(), o.status,
+                   String::from_utf8_lossy(&o.stdout),
+                   String::from_utf8_lossy(&o.stderr));
+        }
+    }
+}
+
+fn nice_err<P: AsRef<Path>, T, E: error::Error>(
+    path: P,
+    res: Result<T, E>,
+) -> T {
+    match res {
+        Ok(t) => t,
+        Err(err) => {
+            panic!("{}: {:?}", path.as_ref().display(), err);
+        }
+    }
+}
+
+fn repeat<F: FnMut() -> io::Result<()>>(mut f: F) -> io::Result<()> {
+    let mut last_err = None;
+    for _ in 0..10 {
+        if let Err(err) = f() {
+            last_err = Some(err);
+            thread::sleep(Duration::from_millis(500));
+        } else {
+            return Ok(());
+        }
+    }
+    Err(last_err.unwrap())
+}