Improve error reporting for IO issues

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## [Unreleased]
 * Added new (empty) diagnostic page served from the server
+* Added better error messages for when a file is missing that's referenced by a Rojo project
 
 ## [0.5.0 Alpha 2](https://github.com/LPGhatguy/rojo/releases/tag/v0.5.0-alpha.2) (January 28, 2019)
 * Added support for `.model.json` files, compatible with 0.4.x

server/src/commands/build.rs

@@ -10,7 +10,7 @@ use failure::Fail;
 use crate::{
     rbx_session::construct_oneoff_tree,
     project::{Project, ProjectLoadFuzzyError},
-    imfs::Imfs,
+    imfs::{Imfs, FsError},
 };
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -55,14 +55,18 @@ pub enum BuildError {
     XmlModelEncodeError(rbx_xml::EncodeError),
 
     #[fail(display = "Binary model file error")]
-    BinaryModelEncodeError(rbx_binary::EncodeError)
+    BinaryModelEncodeError(rbx_binary::EncodeError),
+
+    #[fail(display = "{}", _0)]
+    FsError(#[fail(cause)] FsError),
 }
 
 impl_from!(BuildError {
     ProjectLoadFuzzyError => ProjectLoadError,
     io::Error => IoError,
     rbx_xml::EncodeError => XmlModelEncodeError,
-    rbx_binary::EncodeError => BinaryModelEncodeError
+    rbx_binary::EncodeError => BinaryModelEncodeError,
+    FsError => FsError,
 });
 
 pub fn build(options: &BuildOptions) -> Result<(), BuildError> {

server/src/commands/serve.rs

@@ -9,6 +9,7 @@ use failure::Fail;
 use crate::{
     project::{Project, ProjectLoadFuzzyError},
     web::Server,
+    imfs::FsError,
     live_session::LiveSession,
 };
 
@@ -24,10 +25,14 @@ pub struct ServeOptions {
 pub enum ServeError {
    #[fail(display = "Project load error: {}", _0)]
    ProjectLoadError(#[fail(cause)] ProjectLoadFuzzyError),
+
+   #[fail(display = "{}", _0)]
+   FsError(#[fail(cause)] FsError),
 }
 
 impl_from!(ServeError {
     ProjectLoadFuzzyError => ProjectLoadError,
+    FsError => FsError,
 });
 
 pub fn serve(options: &ServeOptions) -> Result<(), ServeError> {
@@ -38,7 +43,7 @@ pub fn serve(options: &ServeOptions) -> Result<(), ServeError> {
     info!("Found project at {}", project.file_location.display());
     info!("Using project {:#?}", project);
 
-    let live_session = Arc::new(LiveSession::new(Arc::clone(&project)).unwrap());
+    let live_session = Arc::new(LiveSession::new(Arc::clone(&project))?);
     let server = Server::new(Arc::clone(&live_session));
 
     let port = options.port

server/src/commands/upload.rs

@@ -11,7 +11,7 @@ use reqwest::header::{ACCEPT, USER_AGENT, CONTENT_TYPE, COOKIE};
 use crate::{
     rbx_session::construct_oneoff_tree,
     project::{Project, ProjectLoadFuzzyError},
-    imfs::Imfs,
+    imfs::{Imfs, FsError},
 };
 
 #[derive(Debug, Fail)]
@@ -33,6 +33,9 @@ pub enum UploadError {
 
     #[fail(display = "XML model file error")]
     XmlModelEncodeError(rbx_xml::EncodeError),
+
+    #[fail(display = "{}", _0)]
+    FsError(#[fail(cause)] FsError),
 }
 
 impl_from!(UploadError {
@@ -40,6 +43,7 @@ impl_from!(UploadError {
     io::Error => IoError,
     reqwest::Error => HttpError,
     rbx_xml::EncodeError => XmlModelEncodeError,
+    FsError => FsError,
 });
 
 #[derive(Debug)]

server/src/imfs.rs

@@ -1,15 +1,41 @@
 use std::{
     collections::{HashMap, HashSet},
     path::{self, Path, PathBuf},
+    fmt,
     fs,
     io,
 };
 
+use failure::Fail;
 use serde_derive::{Serialize, Deserialize};
 
 use crate::project::{Project, ProjectNode};
 
-fn add_sync_points(imfs: &mut Imfs, project_node: &ProjectNode) -> io::Result<()> {
+/// A wrapper around io::Error that also attaches the path associated with the
+/// error.
+#[derive(Debug, Fail)]
+pub struct FsError {
+    #[fail(cause)]
+    inner: io::Error,
+    path: PathBuf,
+}
+
+impl FsError {
+    fn new<P: Into<PathBuf>>(inner: io::Error, path: P) -> FsError {
+        FsError {
+            inner,
+            path: path.into(),
+        }
+    }
+}
+
+impl fmt::Display for FsError {
+    fn fmt(&self, output: &mut fmt::Formatter) -> fmt::Result {
+        write!(output, "{}: {}", self.path.display(), self.inner)
+    }
+}
+
+fn add_sync_points(imfs: &mut Imfs, project_node: &ProjectNode) -> Result<(), FsError> {
     match project_node {
         ProjectNode::Instance(node) => {
             for child in node.children.values() {
@@ -44,7 +70,7 @@ impl Imfs {
         }
     }
 
-    pub fn add_roots_from_project(&mut self, project: &Project) -> io::Result<()> {
+    pub fn add_roots_from_project(&mut self, project: &Project) -> Result<(), FsError> {
         add_sync_points(self, &project.tree)
     }
 
@@ -63,7 +89,7 @@ impl Imfs {
         self.items.get(path)
     }
 
-    pub fn add_root(&mut self, path: &Path) -> io::Result<()> {
+    pub fn add_root(&mut self, path: &Path) -> Result<(), FsError> {
         debug_assert!(path.is_absolute());
         debug_assert!(!self.is_within_roots(path));
 
@@ -84,21 +110,21 @@ impl Imfs {
         }
     }
 
-    pub fn path_created(&mut self, path: &Path) -> io::Result<()> {
+    pub fn path_created(&mut self, path: &Path) -> Result<(), FsError> {
         debug_assert!(path.is_absolute());
         debug_assert!(self.is_within_roots(path));
 
         self.descend_and_read_from_disk(path)
     }
 
-    pub fn path_updated(&mut self, path: &Path) -> io::Result<()> {
+    pub fn path_updated(&mut self, path: &Path) -> Result<(), FsError> {
         debug_assert!(path.is_absolute());
         debug_assert!(self.is_within_roots(path));
 
         self.descend_and_read_from_disk(path)
     }
 
-    pub fn path_removed(&mut self, path: &Path) -> io::Result<()> {
+    pub fn path_removed(&mut self, path: &Path) -> Result<(), FsError> {
         debug_assert!(path.is_absolute());
         debug_assert!(self.is_within_roots(path));
 
@@ -111,7 +137,7 @@ impl Imfs {
         Ok(())
     }
 
-    pub fn path_moved(&mut self, from_path: &Path, to_path: &Path) -> io::Result<()> {
+    pub fn path_moved(&mut self, from_path: &Path, to_path: &Path) -> Result<(), FsError> {
         self.path_removed(from_path)?;
         self.path_created(to_path)?;
         Ok(())
@@ -161,9 +187,9 @@ impl Imfs {
         }
     }
 
-    fn descend_and_read_from_disk(&mut self, path: &Path) -> io::Result<()> {
+    fn descend_and_read_from_disk(&mut self, path: &Path) -> Result<(), FsError> {
         let root_path = self.get_root_path(path)
-            .expect("Tried to mkdirp for path that wasn't within roots!");
+            .expect("Tried to descent and read for path that wasn't within roots!");
 
         // If this path is a root, we should read the entire thing.
         if root_path == path {
@@ -193,11 +219,13 @@ impl Imfs {
         Ok(())
     }
 
-    fn read_from_disk(&mut self, path: &Path) -> io::Result<()> {
-        let metadata = fs::metadata(path)?;
+    fn read_from_disk(&mut self, path: &Path) -> Result<(), FsError> {
+        let metadata = fs::metadata(path)
+            .map_err(|e| FsError::new(e, path))?;
 
         if metadata.is_file() {
-            let contents = fs::read(path)?;
+            let contents = fs::read(path)
+                .map_err(|e| FsError::new(e, path))?;
             let item = ImfsItem::File(ImfsFile {
                 path: path.to_path_buf(),
                 contents,
@@ -218,8 +246,13 @@ impl Imfs {
 
             self.items.insert(path.to_path_buf(), item);
 
-            for entry in fs::read_dir(path)? {
-                let entry = entry?;
+            let dir_children = fs::read_dir(path)
+                .map_err(|e| FsError::new(e, path))?;
+
+            for entry in dir_children {
+                let entry = entry
+                    .map_err(|e| FsError::new(e, path))?;
+
                 let child_path = entry.path();
 
                 self.read_from_disk(&child_path)?;

server/src/live_session.rs

@@ -1,11 +1,10 @@
 use std::{
     sync::{Arc, Mutex},
-    io,
 };
 
 use crate::{
     fs_watcher::FsWatcher,
-    imfs::Imfs,
+    imfs::{Imfs, FsError},
     message_queue::MessageQueue,
     project::Project,
     rbx_session::RbxSession,
@@ -24,7 +23,7 @@ pub struct LiveSession {
 }
 
 impl LiveSession {
-    pub fn new(project: Arc<Project>) -> io::Result<LiveSession> {
+    pub fn new(project: Arc<Project>) -> Result<LiveSession, FsError> {
         let imfs = {
             let mut imfs = Imfs::new();
             imfs.add_roots_from_project(&project)?;

test-projects/missing-files/roblox-project.json

@@ -0,0 +1,6 @@
+{
+  "name": "missing-files",
+  "tree": {
+    "$path": "does-not-exist"
+  }
+}