moved config settings to separate module.

src/settings.rs

@@ -0,0 +1,50 @@
+use config::{Config, ConfigError};
+use serde::Deserialize;
+
+#[derive(Debug, Deserialize)]
+//#[allow(unused)]
+pub struct Settings {
+    pub address: String,
+    pub port: u16,
+}
+
+impl Settings {
+    pub fn new() -> Result<Self, ConfigError> {
+        let s = Config::builder()
+            .set_default("port", 9090)?
+            .set_default("address", "127.0.0.1")?
+            .add_source(
+                config::Environment::with_prefix("MTT")
+                    .try_parsing(true)
+                    .separator("_")
+                    .list_separator(" "),
+            )
+            .build()?;
+        s.try_deserialize()
+    }
+}
+
+#[cfg(test)]
+mod settings_tests {
+    use super::*;
+    use serial_test::serial;
+
+    #[test]
+    #[serial]
+    fn defaults() {
+        let set = Settings::new().unwrap();
+        println!("{:?}", set);
+        assert_eq!(set.port, 9090);
+        assert_eq!(set.address, "127.0.0.1");
+    }
+
+    #[test]
+    #[serial]
+    fn port_env() {
+        std::env::set_var("MTT_PORT", "7825");
+        let set = Settings::new().unwrap();
+        println!("{:?}", set);
+        assert_eq!(set.port, 7825);
+        std::env::remove_var("MTT_PORT");
+    }
+}