Simplify regression tests with assert_cmd crate

Cargo.toml

@@ -40,6 +40,7 @@ edit = "0.1.5"
 erased-serde = "0.4.9"
 
 [dev-dependencies]
+assert_cmd = "2.1.2"
 map-macro = "0.3.0"
 rstest = {version = "0.26.1", default-features = false, features = ["crate-name"]}
 yaml-rust2 = {version = "0.11.0", default-features = false}

docs/developer_guide/architecture_quickstart.md

@@ -144,12 +144,11 @@ bundled with the MUSE2 executable ([see user guide for more detail][user-guide-e
 As these are intended as both a kind of documentation and templates, they should ideally be kept as
 simple as possible.
 
-If you add a new example model, please also add a regression test ([see here for an
-example][regression-test-example]).
+If you add a new example model, please also add a regression test to [`tests/regression.rs`].
 
 [`examples`]: https://github.com/EnergySystemsModellingLab/MUSE2/blob/main/examples/
 [user-guide-example-models]: https://energysystemsmodellinglab.github.io/MUSE2/user_guide.html#example-models
-[regression-test-example]: https://github.com/EnergySystemsModellingLab/MUSE2/blob/main/tests/regression_muse1_default.rs
+[`tests/regression.rs`]: https://github.com/EnergySystemsModellingLab/MUSE2/blob/main/tests/regression.rs
 
 ## Unit types
 

src/cli.rs

@@ -37,8 +37,8 @@ pub struct RunOpts {
     #[arg(long)]
     pub overwrite: bool,
     /// Whether to write additional information to CSV files
-    #[arg(long, value_name = "BOOL", num_args = 0..=1, default_missing_value = "true")]
-    pub debug_model: Option<bool>,
+    #[arg(long)]
+    pub debug_model: bool,
 }
 
 /// Options for the `graph` command
@@ -94,12 +94,10 @@ impl Commands {
     /// Execute the supplied CLI command
     fn execute(self) -> Result<()> {
         match self {
-            Self::Run { model_dir, opts } => handle_run_command(&model_dir, &opts, None),
+            Self::Run { model_dir, opts } => handle_run_command(&model_dir, &opts),
             Self::Example { subcommand } => subcommand.execute(),
-            Self::Validate { model_dir } => handle_validate_command(&model_dir, None),
-            Self::SaveGraphs { model_dir, opts } => {
-                handle_save_graphs_command(&model_dir, &opts, None)
-            }
+            Self::Validate { model_dir } => handle_validate_command(&model_dir),
+            Self::SaveGraphs { model_dir, opts } => handle_save_graphs_command(&model_dir, &opts),
             Self::Settings { subcommand } => subcommand.execute(),
         }
     }
@@ -126,21 +124,12 @@ pub fn run_cli() -> Result<()> {
 }
 
 /// Handle the `run` command.
-pub fn handle_run_command(
-    model_path: &Path,
-    opts: &RunOpts,
-    settings: Option<Settings>,
-) -> Result<()> {
-    // Load program settings, if not provided
-    let mut settings = if let Some(settings) = settings {
-        settings
-    } else {
-        Settings::load().context("Failed to load settings.")?
-    };
+pub fn handle_run_command(model_path: &Path, opts: &RunOpts) -> Result<()> {
+    let mut settings = Settings::load_or_default().context("Failed to load settings.")?;
 
     // These settings can be overridden by command-line arguments
-    if let Some(opt) = opts.debug_model {
-        settings.debug_model = opt;
+    if opts.debug_model {
+        settings.debug_model = true;
     }
     if opts.overwrite {
         settings.overwrite = true;
@@ -186,13 +175,8 @@ pub fn handle_run_command(
 }
 
 /// Handle the `validate` command.
-pub fn handle_validate_command(model_path: &Path, settings: Option<Settings>) -> Result<()> {
-    // Load program settings, if not provided
-    let settings = if let Some(settings) = settings {
-        settings
-    } else {
-        Settings::load().context("Failed to load settings.")?
-    };
+pub fn handle_validate_command(model_path: &Path) -> Result<()> {
+    let settings = Settings::load_or_default().context("Failed to load settings.")?;
 
     // Initialise program logger (we won't save log files when running the validate command)
     log::init(&settings.log_level, None).context("Failed to initialise logging.")?;
@@ -205,17 +189,8 @@ pub fn handle_validate_command(model_path: &Path, settings: Option<Settings>) ->
 }
 
 /// Handle the `save-graphs` command.
-pub fn handle_save_graphs_command(
-    model_path: &Path,
-    opts: &GraphOpts,
-    settings: Option<Settings>,
-) -> Result<()> {
-    // Load program settings, if not provided
-    let mut settings = if let Some(settings) = settings {
-        settings
-    } else {
-        Settings::load().context("Failed to load settings.")?
-    };
+pub fn handle_save_graphs_command(model_path: &Path, opts: &GraphOpts) -> Result<()> {
+    let mut settings = Settings::load_or_default().context("Failed to load settings.")?;
 
     if opts.overwrite {
         settings.overwrite = true;

src/cli/example.rs

@@ -3,7 +3,6 @@ use super::{RunOpts, handle_run_command};
 use crate::example::patches::{get_patch_names, get_patches};
 use crate::example::{Example, get_example_names};
 use crate::patch::ModelPatch;
-use crate::settings::Settings;
 use anyhow::{Context, Result};
 use clap::Subcommand;
 use std::fs;
@@ -59,7 +58,7 @@ impl ExampleSubcommands {
                 new_path,
             } => handle_example_extract_command(&name, new_path.as_deref(), patch)?,
             Self::Run { name, patch, opts } => {
-                handle_example_run_command(&name, patch, &opts, None)?;
+                handle_example_run_command(&name, patch, &opts)?;
             }
         }
 
@@ -127,37 +126,9 @@ fn extract_example(name: &str, patch: bool, dest: &Path) -> Result<()> {
 }
 
 /// Handle the `example run` command.
-pub fn handle_example_run_command(
-    name: &str,
-    patch: bool,
-    opts: &RunOpts,
-    settings: Option<Settings>,
-) -> Result<()> {
+pub fn handle_example_run_command(name: &str, patch: bool, opts: &RunOpts) -> Result<()> {
     let temp_dir = TempDir::new().context("Failed to create temporary directory")?;
     let model_path = temp_dir.path().join(name);
     extract_example(name, patch, &model_path)?;
-    handle_run_command(&model_path, opts, settings)
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use rstest::rstest;
-
-    fn assert_dir_non_empty(path: &Path) {
-        assert!(
-            path.read_dir().unwrap().next().is_some(),
-            "Directory is empty"
-        );
-    }
-
-    #[rstest]
-    #[case("muse1_default", false)]
-    #[case("simple_divisible", true)]
-    fn check_extract_example(#[case] name: &str, #[case] patch: bool) {
-        let tmp = TempDir::new().unwrap();
-        let dest = tmp.path().join("out");
-        extract_example(name, patch, &dest).unwrap();
-        assert_dir_non_empty(&dest);
-    }
+    handle_run_command(&model_path, opts)
 }

src/settings.rs

@@ -5,6 +5,7 @@ use crate::log::DEFAULT_LOG_LEVEL;
 use anyhow::Result;
 use documented::DocumentedFields;
 use serde::{Deserialize, Serialize};
+use std::env;
 use std::fmt::Write;
 use std::path::{Path, PathBuf};
 
@@ -66,19 +67,25 @@ impl Default for Settings {
 }
 
 impl Settings {
-    /// Read the contents of a settings file from the model directory.
+    /// Read the contents of a settings file from the global MUSE2 configuration directory.
     ///
-    /// If the file is not present, default settings will be used.
+    /// If the file is not present or the user has set the `MUSE2_USE_DEFAULT_SETTINGS` environment
+    /// variable to 1, then the default settings will be used.
     ///
     /// # Returns
     ///
     /// The program settings as a `Settings` struct or an error if loading fails.
-    pub fn load() -> Result<Settings> {
-        Self::load_from_path(&get_settings_file_path())
+    pub fn load_or_default() -> Result<Settings> {
+        if env::var("MUSE2_USE_DEFAULT_SETTINGS").is_ok_and(|v| v == "1") {
+            Ok(Settings::default())
+        } else {
+            Self::from_path_or_default(&get_settings_file_path())
+        }
     }
 
-    /// Read from the specified path, returning
-    fn load_from_path(file_path: &Path) -> Result<Settings> {
+    /// Try to read settings from the specified path, returning `Settings::default()` if it doesn't
+    /// exist
+    fn from_path_or_default(file_path: &Path) -> Result<Settings> {
         if !file_path.is_file() {
             return Ok(Settings::default());
         }
@@ -124,17 +131,17 @@ mod tests {
     use tempfile::tempdir;
 
     #[test]
-    fn settings_load_from_path_no_file() {
+    fn settings_from_path_or_default_no_file() {
         let dir = tempdir().unwrap();
         let file_path = dir.path().join(SETTINGS_FILE_NAME); // NB: doesn't exist
         assert_eq!(
-            Settings::load_from_path(&file_path).unwrap(),
+            Settings::from_path_or_default(&file_path).unwrap(),
             Settings::default()
         );
     }
 
     #[test]
-    fn settings_load_from_path() {
+    fn settings_from_path_or_default() {
         let dir = tempdir().unwrap();
         let file_path = dir.path().join(SETTINGS_FILE_NAME);
 
@@ -144,7 +151,7 @@ mod tests {
         }
 
         assert_eq!(
-            Settings::load_from_path(&file_path).unwrap(),
+            Settings::from_path_or_default(&file_path).unwrap(),
             Settings {
                 log_level: "warn".to_string(),
                 ..Settings::default()