diff --git a/tests/hay.rs b/tests/hay.rs
index 74d2f6cc..a004eae3 100644
--- a/tests/hay.rs
+++ b/tests/hay.rs
@@ -6,19 +6,3 @@ can extract a clew from a wisp of straw or a flake of cigar ash;
 but Doctor Watson has to have it taken out for him and dusted,
 and exhibited clearly, with a label attached.
 ";
-
-pub const CODE: &'static str = "\
-extern crate snap;
-
-use std::io;
-
-fn main() {
-    let stdin = io::stdin();
-    let stdout = io::stdout();
-
-    // Wrap the stdin reader in a Snappy reader.
-    let mut rdr = snap::Reader::new(stdin.lock());
-    let mut wtr = stdout.lock();
-    io::copy(&mut rdr, &mut wtr).expect(\"I/O operation failed\");
-}
-";
diff --git a/tests/macros.rs b/tests/macros.rs
new file mode 100644
index 00000000..edb9f3bb
--- /dev/null
+++ b/tests/macros.rs
@@ -0,0 +1,22 @@
+#[macro_export]
+macro_rules! assert_eq_nice {
+    ($expected:expr, $got:expr) => {
+        let expected = &*$expected;
+        let got = &*$got;
+        if expected != got {
+            panic!("
+printed outputs differ!
+
+expected:
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+{}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+got:
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+{}
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+", expected, got);
+        }
+    }
+}
diff --git a/tests/regression.rs b/tests/regression.rs
new file mode 100644
index 00000000..0454403d
--- /dev/null
+++ b/tests/regression.rs
@@ -0,0 +1,36 @@
+use hay::SHERLOCK;
+use workdir::WorkDir;
+
+// See: https://github.com/BurntSushi/ripgrep/issues/16
+#[test]
+fn r16() {
+    let (wd, mut cmd) = WorkDir::new_with("r16");
+    wd.create_dir(".git");
+    wd.create(".gitignore", "ghi/");
+    wd.create_dir("ghi");
+    wd.create_dir("def/ghi");
+    wd.create("ghi/toplevel.txt", "xyz");
+    wd.create("def/ghi/subdir.txt", "xyz");
+
+    cmd.arg("xyz");
+    wd.assert_err(&mut cmd);
+}
+
+// See: https://github.com/BurntSushi/ripgrep/issues/25
+#[test]
+fn r25() {
+    let (wd, mut cmd) = WorkDir::new_with("r25");
+    wd.create_dir(".git");
+    wd.create(".gitignore", "/llvm/");
+    wd.create_dir("src/llvm");
+    wd.create("src/llvm/foo", "test");
+
+    cmd.arg("test");
+
+    let lines: String = wd.stdout(&mut cmd);
+    assert_eq_nice!("src/llvm/foo:test\n", lines);
+
+    cmd.current_dir(wd.path().join("src"));
+    let lines: String = wd.stdout(&mut cmd);
+    assert_eq_nice!("llvm/foo:test\n", lines);
+}
diff --git a/tests/tests.rs b/tests/tests.rs
index 1c40f22e..480b7b1e 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -1,18 +1,15 @@
-/*!
-This module contains *integration* tests. Their purpose is to test the CLI
-interface. Namely, that passing a flag does what it says on the tin.
-
-Tests for more fine grained behavior (like the search or the globber) should be
-unit tests in their respective modules.
-*/
-
 #![allow(dead_code, unused_imports)]
 
 use std::process::Command;
 
 use workdir::WorkDir;
 
+#[macro_use]
+mod macros;
+
 mod hay;
+mod regression;
+mod util;
 mod workdir;
 
 macro_rules! sherlock {
@@ -47,11 +44,14 @@ macro_rules! clean {
 }
 
 fn path(unix: &str) -> String {
+    unix.to_string()
+    /*
     if cfg!(windows) {
         unix.replace("/", "\\")
     } else {
         unix.to_string()
     }
+    */
 }
 
 fn paths(unix: &[&str]) -> Vec<String> {
diff --git a/tests/util.rs b/tests/util.rs
new file mode 100644
index 00000000..39329a89
--- /dev/null
+++ b/tests/util.rs
@@ -0,0 +1,361 @@
+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::{self, Command};
+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;
+
+/// Dir represents a directory in which tests should be run.
+///
+/// Directories are created from a global atomic counter to avoid duplicates.
+#[derive(Debug)]
+pub struct Dir {
+    /// 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. This directory is also used as the CWD
+    /// for any processes created by the test.
+    dir: PathBuf,
+}
+
+impl Dir {
+    /// 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) -> Dir {
+        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 = env::temp_dir()
+            .join(TEST_DIR)
+            .join(name)
+            .join(&format!("{}", id));
+        nice_err(&dir, repeat(|| fs::create_dir_all(&dir)));
+        Dir {
+            root: root,
+            dir: dir,
+        }
+    }
+
+    /// Create a new file with the given name and contents in this directory,
+    /// or panic on error.
+    pub fn create<P: AsRef<Path>>(&self, name: P, contents: &str) {
+        self.create_bytes(name, contents.as_bytes());
+    }
+
+    /// Try to create a new file with the given name and contents in this
+    /// directory.
+    pub fn try_create<P: AsRef<Path>>(
+        &self,
+        name: P,
+        contents: &str,
+    ) -> io::Result<()> {
+        let path = self.dir.join(name);
+        self.try_create_bytes(path, contents.as_bytes())
+    }
+
+    /// Create a new file with the given name and size.
+    pub fn create_size<P: AsRef<Path>>(&self, name: P, filesize: u64) {
+        let path = self.dir.join(name);
+        let file = nice_err(&path, File::create(&path));
+        nice_err(&path, file.set_len(filesize));
+    }
+
+    /// Create a new file with the given name and contents in this directory,
+    /// or panic on error.
+    pub fn create_bytes<P: AsRef<Path>>(&self, name: P, contents: &[u8]) {
+        let path = self.dir.join(name);
+        nice_err(&path, self.try_create_bytes(&path, contents));
+    }
+
+    /// Try to create a new file with the given name and contents in this
+    /// directory.
+    fn try_create_bytes<P: AsRef<Path>>(
+        &self,
+        path: P,
+        contents: &[u8],
+    ) -> io::Result<()> {
+        let mut file = File::create(&path)?;
+        file.write_all(contents)?;
+        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.
+    ///
+    /// This also:
+    ///
+    /// * Unsets the `RIPGREP_CONFIG_PATH` environment variable.
+    /// * Sets the `--path-separator` to `/` so that paths have the same output
+    ///   on all systems. Tests that need to check `--path-separator` itself
+    ///   can simply pass it again to override it.
+    pub fn command(&self) -> process::Command {
+        let mut cmd = process::Command::new(&self.bin());
+        cmd.env_remove("RIPGREP_CONFIG_PATH");
+        cmd.current_dir(&self.dir);
+        cmd.arg("--path-separator").arg("/");
+        cmd
+    }
+
+    /// Returns the path to the ripgrep executable.
+    pub fn bin(&self) -> PathBuf {
+        if cfg!(windows) {
+            self.root.join("../rg.exe")
+        } else {
+            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_dir<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));
+    }
+
+    /// Creates a directory symlink to the src with the given target name
+    /// in this directory.
+    #[cfg(windows)]
+    pub fn link_dir<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));
+    }
+
+    /// Creates a file symlink to the src with the given target name
+    /// in this directory.
+    #[cfg(not(windows))]
+    pub fn link_file<S: AsRef<Path>, T: AsRef<Path>>(
+        &self,
+        src: S,
+        target: T,
+    ) {
+        self.link_dir(src, target);
+    }
+
+    /// Creates a file symlink to the src with the given target name
+    /// in this directory.
+    #[cfg(windows)]
+    pub fn link_file<S: AsRef<Path>, T: AsRef<Path>>(
+        &self,
+        src: S,
+        target: T,
+    ) {
+        use std::os::windows::fs::symlink_file;
+        let src = self.dir.join(src);
+        let target = self.dir.join(target);
+        let _ = fs::remove_file(&target);
+        nice_err(&target, symlink_file(&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 output = cmd.output().unwrap();
+        self.expect_success(cmd, output)
+    }
+
+    /// Pipe `input` to a command, and collect the output.
+    pub fn pipe(
+        &self,
+        cmd: &mut process::Command,
+        input: &str
+    ) -> process::Output {
+        cmd.stdin(process::Stdio::piped());
+        cmd.stdout(process::Stdio::piped());
+        cmd.stderr(process::Stdio::piped());
+
+        let mut child = cmd.spawn().unwrap();
+
+        // Pipe input to child process using a separate thread to avoid
+        // risk of deadlock between parent and child process.
+        let mut stdin = child.stdin.take().expect("expected standard input");
+        let input = input.to_owned();
+        let worker = thread::spawn(move || {
+            write!(stdin, "{}", input)
+        });
+
+        let output = self.expect_success(
+            cmd,
+            child.wait_with_output().unwrap(),
+        );
+        worker.join().unwrap().unwrap();
+        output
+    }
+
+    /// If `o` is not the output of a successful process run
+    fn expect_success(
+        &self,
+        cmd: &process::Command,
+        o: process::Output
+    ) -> process::Output {
+        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)
+            );
+        }
+    }
+
+    /// Runs the given command and asserts that its exit code matches expected
+    /// exit code.
+    pub fn assert_exit_code(
+        &self,
+        expected_code: i32,
+        cmd: &mut process::Command,
+    ) {
+        let code = cmd.status().unwrap().code().unwrap();
+
+        assert_eq!(
+            expected_code, code,
+            "\n\n===== {:?} =====\n\
+             expected exit code did not match\
+             \n\nexpected: {}\
+             \n\nfound: {}\
+             \n\n=====\n",
+            cmd, expected_code, code
+        );
+    }
+
+    /// Runs the given command and asserts that something was printed to
+    /// stderr.
+    pub fn assert_non_empty_stderr(&self, cmd: &mut process::Command) {
+        let o = cmd.output().unwrap();
+        if o.status.success() || o.stderr.is_empty() {
+            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));
+        }
+    }
+}
+
+/// A simple wrapper around a process::Command with some conveniences.
+#[derive(Debug)]
+pub struct TestCommand {
+    /// The dir used to launched this command.
+    dir: Dir,
+    /// The actual command we use to control the process.
+    cmd: Command,
+}
+
+fn nice_err<T, E: error::Error>(
+    path: &Path,
+    res: Result<T, E>,
+) -> T {
+    match res {
+        Ok(t) => t,
+        Err(err) => panic!("{}: {:?}", path.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())
+}
diff --git a/tests/workdir.rs b/tests/workdir.rs
index 7bf0172d..309eb08f 100644
--- a/tests/workdir.rs
+++ b/tests/workdir.rs
@@ -48,6 +48,15 @@ impl WorkDir {
         }
     }
 
+    /// Like `new`, but also returns a command that whose program is configured
+    /// to ripgrep's executable and has its current working directory set to
+    /// this work dir.
+    pub fn new_with(name: &str) -> (WorkDir, process::Command) {
+        let wd = WorkDir::new(name);
+        let command = wd.command();
+        (wd, command)
+    }
+
     /// Create a new file with the given name and contents in this directory,
     /// or panic on error.
     pub fn create<P: AsRef<Path>>(&self, name: P, contents: &str) {
@@ -106,10 +115,18 @@ impl WorkDir {
 
     /// Creates a new command that is set to use the ripgrep executable in
     /// this working directory.
+    ///
+    /// This also:
+    ///
+    /// * Unsets the `RIPGREP_CONFIG_PATH` environment variable.
+    /// * Sets the `--path-separator` to `/` so that paths have the same output
+    ///   on all systems. Tests that need to check `--path-separator` itself
+    ///   can simply pass it again to override it.
     pub fn command(&self) -> process::Command {
         let mut cmd = process::Command::new(&self.bin());
         cmd.env_remove("RIPGREP_CONFIG_PATH");
         cmd.current_dir(&self.dir);
+        cmd.arg("--path-separator").arg("/");
         cmd
     }