Normalize relative paths from project $path entries

Cargo.toml

@@ -87,6 +87,8 @@ termcolor = "1.0.5"
 thiserror = "1.0.11"
 tokio = "0.1.22"
 uuid = { version = "0.8.1", features = ["v4", "serde"] }
+relative-path = "1.2.1"
+path-slash = "0.1.3"
 
 [target.'cfg(windows)'.dependencies]
 winreg = "0.6.2"

src/snapshot_middleware/project.rs

@@ -1,4 +1,6 @@
-use std::{borrow::Cow, collections::HashMap, path::Path};
+use path_slash::PathExt;
+use relative_path::RelativePath;
+use std::{borrow::Cow, collections::HashMap, path::Path, path::PathBuf};
 
 use memofs::Vfs;
 use rbx_reflection::{get_class_descriptor, try_resolve_value};
@@ -78,7 +80,42 @@ pub fn snapshot_project_node(
         // If the path specified in the project is relative, we assume it's
         // relative to the folder that the project is in, project_folder.
         let path = if path.is_relative() {
-            Cow::Owned(project_folder.join(path))
+            // Convert paths to use forward slashes for compatibility with the relative-path crate
+            let project_folder_with_slash_separator = match project_folder.to_slash() {
+                Some(p) => p,
+                None => return Ok(None),
+            };
+            let path_with_slash_separator = match path.to_slash() {
+                Some(p) => p,
+                None => return Ok(None),
+            };
+
+            // Join and resolve relative paths
+            let normalized_path = RelativePath::new(&project_folder_with_slash_separator)
+                .join_normalized(&path_with_slash_separator);
+
+            let resolved_path = if PathBuf::from(normalized_path.as_str()).is_relative() {
+                // Resolve path relative to original root if project_folder was absolute
+                normalized_path.to_path(
+                    project_folder
+                        .components()
+                        .next()
+                        .expect("Could not get root of project folder"),
+                )
+            } else {
+                PathBuf::from(normalized_path.as_str())
+            };
+
+            log::trace!(
+                "original {}, project_folder {}, path {}, normalized {}, resolved {}",
+                project_folder.join(path).display(),
+                project_folder_with_slash_separator,
+                path_with_slash_separator,
+                normalized_path,
+                resolved_path.display()
+            );
+
+            Cow::Owned(resolved_path)
         } else {
             Cow::Borrowed(path)
         };
@@ -512,6 +549,46 @@ mod test {
         insta::assert_yaml_snapshot!(instance_snapshot);
     }
 
+    #[test]
+    fn project_with_relative_path() {
+        let _ = env_logger::try_init();
+
+        let mut imfs = InMemoryFs::new();
+        imfs.load_snapshot(
+            "/baz",
+            VfsSnapshot::dir(hashmap! {
+                "other.txt" => VfsSnapshot::file("Hello, world!"),
+            }),
+        )
+        .unwrap();
+        imfs.load_snapshot(
+            "/foo/bar",
+            VfsSnapshot::dir(hashmap! {
+                "default.project.json" => VfsSnapshot::file(r#"
+                    {
+                        "name": "path-project",
+                        "tree": {
+                            "$path": "../../baz/other.txt"
+                        }
+                    }
+                "#),
+            }),
+        )
+        .unwrap();
+
+        let mut vfs = Vfs::new(imfs);
+
+        let instance_snapshot = snapshot_project(
+            &InstanceContext::default(),
+            &mut vfs,
+            Path::new("/foo/bar/default.project.json"),
+        )
+        .expect("snapshot error")
+        .expect("snapshot returned no instances");
+
+        insta::assert_yaml_snapshot!(instance_snapshot);
+    }
+
     /// Ensures that if a property is defined both in the resulting instance
     /// from $path and also in $properties, that the $properties value takes
     /// precedence.

src/snapshot_middleware/snapshots/librojo__snapshot_middleware__project__test__project_with_relative_path.snap

@@ -0,0 +1,21 @@
+---
+source: src/snapshot_middleware/project.rs
+expression: instance_snapshot
+---
+snapshot_id: ~
+metadata:
+  ignore_unknown_instances: false
+  instigating_source:
+    Path: /foo/bar/default.project.json
+  relevant_paths:
+    - /baz/other.txt
+    - /baz/other.meta.json
+    - /foo/bar/default.project.json
+  context: {}
+name: path-project
+class_name: StringValue
+properties:
+  Value:
+    Type: String
+    Value: "Hello, world!"
+children: []