Overhaul error system

Separate diagnostics reporting from high-level engine results.

(lost the much longer commit message I wrote, sorry)

Cargo.toml

@@ -35,6 +35,7 @@ edition.workspace = true
 quake_core = { path = "crates/quake_core" }
 quake_engine = { path = "crates/quake_engine" }
 
+anyhow = "1.0.81"
 clap = { version = "4.4.18", features = ["cargo", "wrap_help"] }
 serde_json = "1.0.113"
 

crates/quake_core/src/lib.rs

@@ -10,18 +10,10 @@ pub mod utils;
 /// descending precedence.
 pub const BUILD_SCRIPT_NAMES: &[&str] = &["build.quake", "build.quake.nu"];
 
-pub mod exit_codes {
-    pub const TASK_RUN_FAIL: i32 = 1;
-    pub const TASK_DECL_FAIL: i32 = 2;
-    pub const LOAD_FAIL: i32 = 3;
-
-    pub const INTERNAL_ERROR: i32 = 255;
-}
-
 pub mod prelude {
     pub use quake_errors::*;
     pub use quake_log::{log_error, log_fatal, log_info, log_warning, panic_bug};
 
+    pub use crate::match_expr;
     pub use crate::project::*;
-    pub use crate::{exit_codes, match_expr};
 }

crates/quake_core/src/metadata.rs

@@ -35,7 +35,7 @@ impl Metadata {
         self.tasks.get(task_id)
     }
 
-    pub fn find_task(&self, name: &str, span: Option<Span>) -> Result<&Arc<Task>> {
+    pub fn find_task(&self, name: &str, span: Option<Span>) -> DiagResult<&Arc<Task>> {
         self.tasks
             .iter()
             .find(|t| t.name.item == name)
@@ -48,7 +48,7 @@ impl Metadata {
             })
     }
 
-    pub fn find_task_id(&self, name: &str, span: Option<Span>) -> Result<TaskId> {
+    pub fn find_task_id(&self, name: &str, span: Option<Span>) -> DiagResult<TaskId> {
         self.tasks
             .iter()
             .position(|t| t.name.item == name)
@@ -66,7 +66,7 @@ impl Metadata {
         name: String,
         task: impl Into<Arc<Task>>,
         span: Span,
-    ) -> Result<TaskId> {
+    ) -> DiagResult<TaskId> {
         if let Ok(existing) = self.find_task(&name, None) {
             return Err(errors::TaskDuplicateDefinition {
                 name,

crates/quake_core/src/project.rs

@@ -19,16 +19,16 @@ impl Project {
     /// ## Errors
     ///
     /// If the project root is not a directory, this will return an `Err` with
-    /// [`errors::ProjectNotFound`].
-    /// If no build script file is found in the
+    /// [`errors::ProjectNotFound`]. If no build script file is found in the
     /// project root, this will return an `Err` with
     /// [`errors::BuildScriptNotFound`].
-    pub fn new(project_root: PathBuf) -> Result<Self> {
+    pub fn new(project_root: PathBuf) -> EngineResult<Self> {
         if !project_root.is_dir() {
-            return Err(errors::ProjectNotFound.into());
+            bail!("{}", errors::ProjectNotFound);
         }
 
-        let build_script = find_build_script(&project_root).ok_or(errors::BuildScriptNotFound)?;
+        let build_script = find_build_script(&project_root)
+            .ok_or_else(|| error!("{}", errors::BuildScriptNotFound))?;
 
         Ok(Self {
             project_root,
@@ -43,9 +43,10 @@ impl Project {
     ///
     /// If the project root is not a directory or no project can be found, this
     /// will return an `Err` with [`errors::ProjectNotFound`].
-    pub fn locate(current_dir: impl AsRef<Path>) -> Result<Self> {
+    pub fn locate(current_dir: impl AsRef<Path>) -> EngineResult<Self> {
         if !current_dir.as_ref().is_dir() {
-            return Err(errors::ProjectNotFound.into());
+            eprintln!("{}", errors::ProjectNotFound);
+            bail!(EngineError::LoadFailed);
         }
 
         if let Some(build_script) = find_build_script(&current_dir) {
@@ -56,7 +57,8 @@ impl Project {
         } else if let Some(parent) = current_dir.as_ref().parent() {
             Self::locate(parent)
         } else {
-            Err(errors::ProjectNotFound.into())
+            eprintln!("{}", errors::ProjectNotFound);
+            bail!("{}", EngineError::LoadFailed);
         }
     }
 

crates/quake_core/src/utils.rs

@@ -13,17 +13,17 @@ pub fn get_init_cwd() -> Option<PathBuf> {
         .or_else(|| std::env::var(PWD_ENV).ok().map(Into::into))
 }
 
-pub fn latest_timestamp(paths: &[impl AsRef<Path>]) -> Result<Option<SystemTime>> {
+pub fn latest_timestamp(paths: &[impl AsRef<Path>]) -> DiagResult<Option<SystemTime>> {
     Ok(paths
         .iter()
         .filter(|p| p.as_ref().exists())
         .map(|s| fs::metadata(s).and_then(|m| m.modified()).into_diagnostic())
-        .collect::<Result<Vec<_>>>()?
+        .collect::<DiagResult<Vec<_>>>()?
         .into_iter()
         .max())
 }
 
-pub fn is_dirty(task: &TaskCallMetadata) -> Result<bool> {
+pub fn is_dirty(task: &TaskCallMetadata) -> DiagResult<bool> {
     // if either is undefined, assume dirty
     if task.sources.is_empty() || task.artifacts.is_empty() {
         return Ok(true);