Add (so far trivial) unit tests.

examples/opticscenery.rs

@@ -4,7 +4,7 @@ use std::io::Write;
 
 fn main() {
     println!("opticscenery example");
-    let mut scenery = OpticScenery::default();
+    let mut scenery = OpticScenery::new();
     scenery.set_description("OpticScenery demo".into());
     println!("default opticscenery: {:?}", scenery);
     println!("export to `dot` format: {}", scenery.to_dot());

src/optic_node.rs

@@ -19,3 +19,24 @@ impl OpticNode {
         self.name.as_ref()
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::OpticNode;
+    #[test]
+    fn new() {
+      let node = OpticNode::new("Test".into());
+      assert_eq!(node.name, "Test".to_owned());
+    }
+    #[test]
+    fn set_name() { 
+        let mut node = OpticNode::new("Test".into());
+        node.set_name("Test2".into());
+        assert_eq!(node.name, "Test2".to_owned())
+    }
+    #[test]
+    fn name() { 
+        let node = OpticNode::new("Test".into());
+        assert_eq!(node.name(), "Test".to_owned())
+    }
+}

src/optic_scenery.rs

@@ -41,3 +41,34 @@ impl OpticScenery {
         self.description.as_ref()
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    #[test]
+    fn new() {
+        let scenery= OpticScenery::new();
+        assert_eq!(scenery.description, "".to_owned());
+        assert_eq!(scenery.g.edge_count(),0);
+        assert_eq!(scenery.g.node_count(),0);
+    }
+    #[test]
+    fn to_dot() {
+        let mut scenery=OpticScenery::new();
+        scenery.set_description("Test".into());
+        assert_eq!(scenery.to_dot(),"digraph {\n  label=\"Test\"\n}");
+    }
+    #[test]
+    fn set_description() {
+        let mut scenery=OpticScenery::new();
+        scenery.set_description("Test".into());
+        assert_eq!(scenery.description, "Test".to_owned())
+    }
+    #[test]
+    fn description() {
+        let mut scenery=OpticScenery::new();
+        scenery.set_description("Test".into());
+        assert_eq!(scenery.description(), "Test".to_owned())
+    }
+
+}
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