refactor: more entrypoint simplifications

initial model calculated in its own function

src/main.rs

@@ -84,6 +84,26 @@ fn parse_args(args: Vec<String>) -> Option<CmdLineArgs> {
     });
 }
 
+fn get_initial_model(file_path: &Option<PathBuf>) -> Result<Model> {
+    return if let Some(ref path) = file_path {
+        if path.exists() {
+            let mut m = persistence::load(path)
+                .with_context(|| format!("Failed to load {}", path.display()))?;
+            m.normalize_view_state();
+            Ok(m)
+        } else {
+            let name = path
+                .file_stem()
+                .and_then(|s| s.to_str())
+                .unwrap_or("New Model")
+                .to_string();
+            Ok(Model::new(name))
+        }
+    } else {
+        Ok(Model::new("New Model"))
+    }
+}
+
 fn main() -> Result<()> {
     let args: Vec<String> = std::env::args().collect();
     let maybe_cmd_line_args = parse_args(args);
@@ -94,23 +114,7 @@ fn main() -> Result<()> {
     let cmd_line_args = maybe_cmd_line_args.unwrap();
 
     // Load or create model
-    let mut model = if let Some(ref path) = cmd_line_args.file_path {
+    let mut model = get_initial_model(&cmd_line_args.file_path)?;
-        if path.exists() {
-            let mut m = persistence::load(path)
-                .with_context(|| format!("Failed to load {}", path.display()))?;
-            m.normalize_view_state();
-            m
-        } else {
-            let name = path
-                .file_stem()
-                .and_then(|s| s.to_str())
-                .unwrap_or("New Model")
-                .to_string();
-            Model::new(name)
-        }
-    } else {
-        Model::new("New Model")
-    };
 
     // Headless mode
     if !cmd_line_args.headless_cmds.is_empty() || cmd_line_args.headless_script.is_some() {