diff --git a/justfile b/justfile
index 63a3a1a..d503ca2 100644
--- a/justfile
+++ b/justfile
@@ -1,3 +1,8 @@
+build:
+  cargo build
+  cargo test
+  cargo clippy
+
 install-hooks:
   @echo "Installing git hooks"
   git config core.hooksPath .git-hooks
diff --git a/tests/fs.rs b/tests/fs.rs
new file mode 100644
index 0000000..a2d271a
--- /dev/null
+++ b/tests/fs.rs
@@ -0,0 +1,312 @@
+use assert2::let_assert;
+
+use kxio::fs;
+
+type TestResult = Result<(), fs::Error>;
+
+mod path_of {
+    use super::*;
+
+    #[test]
+    fn validate_fails_on_path_traversal() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+
+        let_assert!(Err(fs::Error::PathTraversal { base, path: _path }) = fs.path_of("..".into()));
+        assert_eq!(base, fs.base());
+
+        Ok(())
+    }
+
+    #[test]
+    fn matches_joins() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+
+        let joined = fs.base().join("foo").join("bar");
+        let path_of = fs
+            .path_of("foo/bar".into())
+            .expect("parse foo/bar into path");
+
+        assert_eq!(joined, path_of);
+
+        Ok(())
+    }
+}
+
+mod file {
+    use super::*;
+
+    #[test]
+    /// Write to a file, read it, verify it exists, is a file and has the expected contents
+    fn write_read_file_exists() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let pathbuf = fs.base().join("foo");
+
+        let mut file = fs.file(&pathbuf);
+        file.write("content").expect("write");
+        let c = file.reader().expect("reader").to_string();
+        assert_eq!(c, "content");
+
+        let mut path = fs.path(&pathbuf);
+        let exists = path.exists().expect("exists");
+        assert!(exists);
+
+        let is_file = path.is_file().expect("is_file");
+        assert!(is_file);
+
+        Ok(())
+    }
+}
+
+mod dir_create {
+    use super::*;
+    #[test]
+    fn should_create_a_dir() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let pathbuf = fs.base().join("subdir");
+
+        fs.dir(&pathbuf).create().expect("create");
+
+        let exists = fs.path(&pathbuf).exists().expect("exitss");
+        assert!(exists);
+
+        let is_dir = fs.path(&pathbuf).is_dir().expect("is dir");
+        assert!(is_dir);
+
+        Ok(())
+    }
+    #[test]
+    fn should_fail_on_path_traversal() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("..").join("foo");
+        let_assert!(
+            Err(fs::Error::PathTraversal {
+                base: _base,
+                path: _path
+            }) = fs.dir(&path).create()
+        );
+
+        Ok(())
+    }
+}
+
+mod dir_create_all {
+    use super::*;
+
+    #[test]
+    fn should_create_a_dir() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let pathbuf = fs.base().join("subdir").join("child");
+
+        fs.dir(&pathbuf).create_all().expect("create_all");
+
+        let mut path = fs.path(&pathbuf);
+        let exists = path.exists().expect("exists");
+        assert!(exists, "path exists");
+
+        let is_dir = path.is_dir().expect("is_dir");
+        assert!(is_dir, "path is a directory");
+
+        Ok(())
+    }
+    #[test]
+    fn should_fail_on_path_traversal() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("..").join("foo");
+        let_assert!(
+            Err(fs::Error::PathTraversal {
+                base: _base,
+                path: _path
+            }) = fs.dir(&path).create_all()
+        );
+
+        Ok(())
+    }
+}
+
+mod dir_dir_read {
+    use crate::fs::DirItem;
+
+    use super::*;
+
+    #[test]
+    fn should_return_dir_items() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let file1 = fs.base().join("file-1");
+        let dir = fs.base().join("dir");
+        let file2 = dir.join("file-2");
+        fs.file(&file1).write("file-1").expect("write: file-1");
+        fs.dir(&dir).create().expect("create dir");
+        fs.file(&file2).write("file-2").expect("write: file-2");
+
+        let items = fs
+            .dir(fs.base())
+            .read()
+            .expect("dir.read")
+            .filter_map(|i| i.ok())
+            .collect::<Vec<_>>();
+
+        assert_eq!(items.len(), 2);
+        assert!(items.contains(&DirItem::File(file1)));
+        assert!(items.contains(&DirItem::Dir(dir)));
+
+        Ok(())
+    }
+    #[test]
+    fn should_fail_on_not_a_dir() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("file");
+        fs.file(&path).write("contents").expect("write");
+
+        let_assert!(Err(fs::Error::NotADirectory { path: _path }) = fs.dir(&path).read());
+
+        Ok(())
+    }
+    #[test]
+    fn should_fail_on_path_traversal() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("..").join("foo");
+        let_assert!(
+            Err(fs::Error::PathTraversal {
+                base: _base,
+                path: _path
+            }) = fs.dir(&path).read()
+        );
+
+        Ok(())
+    }
+}
+
+mod path_exists {
+    use super::*;
+    #[test]
+    fn should_be_true_when_it_exists() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("foo");
+        fs.file(&path).write("bar").expect("write");
+        let exists = fs.path(&path).exists().expect("exists");
+        assert!(exists);
+
+        Ok(())
+    }
+    #[test]
+    fn should_be_false_when_it_does_not_exist() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("foo");
+        let exists = fs.path(&path).exists().expect("exists");
+        assert!(!exists);
+
+        Ok(())
+    }
+    #[test]
+    fn should_fail_on_path_traversal() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("..").join("foo");
+        let_assert!(
+            Err(fs::Error::PathTraversal {
+                base: _base,
+                path: _path
+            }) = fs.path(&path).exists()
+        );
+
+        Ok(())
+    }
+}
+
+mod path_is_dir {
+    use super::*;
+    #[test]
+    fn should_be_true_when_is_a_dir() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("foo");
+        fs.dir(&path).create().expect("create");
+        let is_dir = fs.path(&path).is_dir().expect("is_dir");
+        assert!(is_dir);
+
+        Ok(())
+    }
+    #[test]
+    fn should_be_false_when_is_a_file() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("foo");
+        fs.file(&path).write("bar").expect("write");
+        let is_dir = fs.path(&path).is_dir().expect("is_dir");
+        assert!(!is_dir);
+
+        Ok(())
+    }
+    #[test]
+    #[ignore]
+    fn should_be_false_when_is_a_link() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("foo");
+        // TODO: (#38) create a link
+        // let_assert!(Ok(_) = fs.file_write(&path, "bar"));
+        let is_dir = fs.path(&path).is_dir().expect("is_dir");
+        assert!(!is_dir);
+
+        Ok(())
+    }
+    #[test]
+    fn should_fail_on_path_traversal() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("..").join("foo");
+        let_assert!(
+            Err(fs::Error::PathTraversal {
+                base: _base,
+                path: _path
+            }) = fs.dir(&path).is_dir()
+        );
+
+        Ok(())
+    }
+}
+
+mod path_is_file {
+    use super::*;
+    #[test]
+    fn should_be_true_when_is_a_file() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("foo");
+        fs.file(&path).write("bar").expect("write");
+
+        let is_file = fs.path(&path).is_file().expect("is_file");
+        assert!(is_file);
+
+        Ok(())
+    }
+    #[test]
+    fn should_be_false_when_is_a_dir() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("foo");
+        fs.dir(&path).create().expect("create");
+        let is_file = fs.path(&path).is_file().expect("is_file");
+        assert!(!is_file);
+
+        Ok(())
+    }
+    #[test]
+    #[ignore]
+    fn should_be_false_when_is_a_link() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("foo");
+        // TODO: (#38) create a link
+        // let_assert!(Ok(_) = fs.file_write(&path, "bar"));
+        let is_file = fs.path(&path).is_file().expect("is_file");
+        assert!(!is_file);
+
+        Ok(())
+    }
+    #[test]
+    fn should_fail_on_path_traversal() -> TestResult {
+        let fs = fs::temp().expect("temp fs");
+        let path = fs.base().join("..").join("foo");
+        let_assert!(
+            Err(fs::Error::PathTraversal {
+                base: _base,
+                path: _path
+            }) = fs.file(&path).is_file()
+        );
+
+        Ok(())
+    }
+}