feat(core): add path builder

migra-core/src/database.rs

@@ -1,4 +1,4 @@
-use postgres::{Client, NoTls, Error};
+use postgres::{Client, Error, NoTls};
 
 pub fn connect(connection_string: &str) -> Result<Client, Error> {
     Client::connect(connection_string, NoTls)

migra-core/src/lib.rs

@@ -1,3 +1,4 @@
 #![deny(clippy::all)]
 
 pub mod database;
+pub mod path;

migra-core/src/path.rs

@@ -0,0 +1,68 @@
+use std::ffi::OsStr;
+use std::path::{Path, PathBuf};
+
+#[derive(Debug, Default)]
+pub struct PathBuilder {
+    buf: PathBuf,
+}
+
+impl PathBuilder {
+    pub fn new<P: AsRef<Path>>(path: P) -> Self {
+        PathBuilder {
+            buf: path.as_ref().to_path_buf(),
+        }
+    }
+
+    pub fn append<P: AsRef<Path>>(&mut self, path: P) -> &mut Self {
+        self.buf.push(path);
+        self
+    }
+
+    pub fn default_extension<S: AsRef<OsStr>>(&mut self, extension: S) -> &mut Self {
+        if self.buf.as_path().extension().is_none() {
+            self.buf.set_extension(extension);
+        }
+        self
+    }
+
+    pub fn build(&self) -> PathBuf {
+        self.buf.clone()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::path::Path;
+    use crate::path::PathBuilder;
+
+    #[test]
+    fn create_path_builder() {
+        let path = PathBuilder::new("test").build();
+
+        assert_eq!(path, Path::new("test"))
+    }
+
+    #[test]
+    fn append_path_to_builder() {
+        let path = PathBuilder::new("directory").append("schema.sql").build();
+
+        assert_eq!(path, Path::new("directory/schema.sql"))
+    }
+
+    #[test]
+    fn add_default_extension_for_path() {
+        let path = PathBuilder::new("directory")
+            .append("schema")
+            .default_extension("sql")
+            .build();
+
+        assert_eq!(path, Path::new("directory/schema.sql"));
+    }
+
+    #[test]
+    fn build_default_path() {
+        let path = PathBuilder::default().build();
+
+        assert_eq!(path, Path::new(""));
+    }
+}