New snapshot tests

server/tests/test_util/mod.rs

@@ -2,30 +2,10 @@ use std::fs::{create_dir, copy};
 use std::path::Path;
 use std::io;
 
-use rouille::Request;
-
 use walkdir::WalkDir;
 
-use librojo::web::Server;
-
-pub trait HttpTestUtil {
-    fn get_string(&self, url: &str) -> String;
-}
-
-impl HttpTestUtil for Server {
-    fn get_string(&self, url: &str) -> String {
-        let info_request = Request::fake_http("GET", url, vec![], vec![]);
-        let response = self.handle_request(&info_request);
-
-        assert_eq!(response.status_code, 200);
-
-        let (mut reader, _) = response.data.into_reader_and_size();
-        let mut body = String::new();
-        reader.read_to_string(&mut body).unwrap();
-
-        body
-    }
-}
+pub mod snapshot;
+pub mod tree;
 
 pub fn copy_recursive(from: &Path, to: &Path) -> io::Result<()> {
     for entry in WalkDir::new(from) {
@@ -51,4 +31,4 @@ pub fn copy_recursive(from: &Path, to: &Path) -> io::Result<()> {
     }
 
     Ok(())
-}
+}

server/tests/test_util/snapshot.rs

@@ -0,0 +1,98 @@
+use std::{
+    fs::{self, File},
+    path::{Path, PathBuf},
+};
+
+use rbx_dom_weak::RbxTree;
+
+use librojo::{
+    project::ProjectNode,
+    snapshot_reconciler::RbxSnapshotInstance,
+};
+
+const SNAPSHOT_EXPECTED_NAME: &str = "expected-snapshot.json";
+
+/// Snapshots contain absolute paths, which simplifies much of Rojo.
+///
+/// For saving snapshots to the disk, we should strip off the project folder
+/// path to make them machine-independent. This doesn't work for paths that fall
+/// outside of the project folder, but that's okay here.
+///
+/// We also need to sort children, since Rojo tends to enumerate the filesystem
+/// in an unpredictable order.
+pub fn anonymize_snapshot(project_folder_path: &Path, snapshot: &mut RbxSnapshotInstance) {
+    match snapshot.metadata.source_path.as_mut() {
+        Some(path) => *path = anonymize_path(project_folder_path, path),
+        None => {},
+    }
+
+    match snapshot.metadata.project_definition.as_mut() {
+        Some((_, project_node)) => anonymize_project_node(project_folder_path, project_node),
+        None => {},
+    }
+
+    snapshot.children.sort_by(|a, b| a.partial_cmp(b).unwrap());
+
+    for child in snapshot.children.iter_mut() {
+        anonymize_snapshot(project_folder_path, child);
+    }
+}
+
+pub fn anonymize_project_node(project_folder_path: &Path, project_node: &mut ProjectNode) {
+    match project_node.path.as_mut() {
+        Some(path) => *path = anonymize_path(project_folder_path, path),
+        None => {},
+    }
+
+    for child_node in project_node.children.values_mut() {
+        anonymize_project_node(project_folder_path, child_node);
+    }
+}
+
+pub fn anonymize_path(project_folder_path: &Path, path: &Path) -> PathBuf {
+    if path.is_absolute() {
+        path.strip_prefix(project_folder_path)
+            .expect("Could not anonymize absolute path")
+            .to_path_buf()
+    } else {
+        path.to_path_buf()
+    }
+}
+
+pub fn read_tree_by_name(path: &Path, identifier: &str) -> Option<RbxTree> {
+    let mut file_path = path.join(identifier);
+    file_path.set_extension("tree.json");
+
+    let contents = fs::read(&file_path).ok()?;
+    let tree: RbxTree = serde_json::from_slice(&contents)
+        .expect("Could not deserialize tree");
+
+    Some(tree)
+}
+
+pub fn write_tree_by_name(path: &Path, identifier: &str, tree: &RbxTree) {
+    let mut file_path = path.join(identifier);
+    file_path.set_extension("tree.json");
+
+    let mut file = File::create(file_path)
+        .expect("Could not open file to write tree");
+
+    serde_json::to_writer_pretty(&mut file, tree)
+        .expect("Could not serialize tree to file");
+}
+
+pub fn read_expected_snapshot(path: &Path) -> Option<Option<RbxSnapshotInstance<'static>>> {
+    let contents = fs::read(path.join(SNAPSHOT_EXPECTED_NAME)).ok()?;
+    let snapshot: Option<RbxSnapshotInstance<'static>> = serde_json::from_slice(&contents)
+        .expect("Could not deserialize snapshot");
+
+    Some(snapshot)
+}
+
+pub fn write_expected_snapshot(path: &Path, snapshot: &Option<RbxSnapshotInstance>) {
+    let mut file = File::create(path.join(SNAPSHOT_EXPECTED_NAME))
+        .expect("Could not open file to write snapshot");
+
+    serde_json::to_writer_pretty(&mut file, snapshot)
+        .expect("Could not serialize snapshot to file");
+}

server/tests/test_util/tree.rs

@@ -0,0 +1,181 @@
+//! Defines a mechanism to compare two RbxTree objects and generate a useful
+//! diff if they aren't the same. These methods ignore IDs, which are randomly
+//! generated whenever a tree is constructed anyways. This makes matching up
+//! pairs of instances that should be the same pretty difficult.
+//!
+//! It relies on a couple different ideas:
+//! - Instances with the same name and class name are matched as the same
+//!   instance. See basic_equal for this logic
+//! - A path of period-delimited names (like Roblox's GetFullName) should be
+//!   enough to debug most issues. If it isn't, we can do something fun like
+//!   generate GraphViz graphs.
+
+use std::{
+    borrow::Cow,
+    collections::HashSet,
+    fmt,
+};
+
+use rbx_dom_weak::{RbxId, RbxTree};
+
+#[derive(Debug)]
+pub struct TreeMismatch {
+    pub path: Cow<'static, str>,
+    pub detail: Cow<'static, str>,
+}
+
+impl TreeMismatch {
+    pub fn new<'a, A: Into<Cow<'a, str>>, B: Into<Cow<'a, str>>>(path: A, detail: B) -> TreeMismatch {
+        TreeMismatch {
+            path: Cow::Owned(path.into().into_owned()),
+            detail: Cow::Owned(detail.into().into_owned()),
+        }
+    }
+
+    pub fn add_parent(mut self, name: &str) -> TreeMismatch {
+        self.path.to_mut().insert(0, '.');
+        self.path.to_mut().insert_str(0, name);
+
+        TreeMismatch {
+            path: self.path,
+            detail: self.detail,
+        }
+    }
+}
+
+impl fmt::Display for TreeMismatch {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        writeln!(formatter, "Tree mismatch at path {}", self.path)?;
+        writeln!(formatter, "{}", self.detail)
+    }
+}
+
+pub fn trees_equal(left_tree: &RbxTree, right_tree: &RbxTree) -> Result<(), TreeMismatch> {
+    let left_id = left_tree.get_root_id();
+    let right_id = right_tree.get_root_id();
+
+    basic_equal(left_tree, left_id, right_tree, right_id)?;
+    properties_equal(left_tree, left_id, right_tree, right_id)?;
+
+    children_equal(left_tree, left_id, right_tree, right_id)
+        .map_err(|e| {
+            let left_instance = left_tree.get_instance(left_id)
+                .expect("ID did not exist in left tree");
+
+            e.add_parent(&left_instance.name)
+        })
+}
+
+fn basic_equal(left_tree: &RbxTree, left_id: RbxId, right_tree: &RbxTree, right_id: RbxId) -> Result<(), TreeMismatch> {
+    let left_instance = left_tree.get_instance(left_id)
+        .expect("ID did not exist in left tree");
+
+    let right_instance = right_tree.get_instance(right_id)
+        .expect("ID did not exist in right tree");
+
+    if left_instance.name != right_instance.name {
+        return Err(TreeMismatch::new(&left_instance.name, "Name did not match"));
+    }
+
+    if left_instance.class_name != right_instance.class_name {
+        return Err(TreeMismatch::new(&left_instance.name, "Class name did not match"));
+    }
+
+    Ok(())
+}
+
+fn properties_equal(left_tree: &RbxTree, left_id: RbxId, right_tree: &RbxTree, right_id: RbxId) -> Result<(), TreeMismatch> {
+    let left_instance = left_tree.get_instance(left_id)
+        .expect("ID did not exist in left tree");
+
+    let right_instance = right_tree.get_instance(right_id)
+        .expect("ID did not exist in right tree");
+
+    let mut visited = HashSet::new();
+
+    for (key, left_value) in &left_instance.properties {
+        visited.insert(key);
+
+        let right_value = right_instance.properties.get(key);
+
+        if Some(left_value) != right_value {
+            let message = format!(
+                "Property {}:\n\tLeft: {:?}\n\tRight: {:?}",
+                key,
+                Some(left_value),
+                right_value,
+            );
+
+            return Err(TreeMismatch::new(&left_instance.name, message));
+        }
+    }
+
+    for (key, right_value) in &right_instance.properties {
+        if visited.contains(key) {
+            continue;
+        }
+
+        let left_value = left_instance.properties.get(key);
+
+        if left_value != Some(right_value) {
+            let message = format!(
+                "Property {} was {:?} on left and {:?} on right",
+                key,
+                left_value,
+                Some(right_value),
+            );
+
+            return Err(TreeMismatch::new(&left_instance.name, message));
+        }
+    }
+
+    Ok(())
+}
+
+fn children_equal(left_tree: &RbxTree, left_id: RbxId, right_tree: &RbxTree, right_id: RbxId) -> Result<(), TreeMismatch> {
+    let left_instance = left_tree.get_instance(left_id)
+        .expect("ID did not exist in left tree");
+
+    let right_instance = right_tree.get_instance(right_id)
+        .expect("ID did not exist in right tree");
+
+    let left_children = left_instance.get_children_ids();
+    let right_children = right_instance.get_children_ids();
+
+    if left_children.len() != right_children.len() {
+        return Err(TreeMismatch::new(&left_instance.name, "Instances had different numbers of children"));
+    }
+
+    let mut right_visited = HashSet::new();
+
+    for left_child_id in left_children {
+        let mut found_match = false;
+
+        for right_child_id in right_children {
+            if right_visited.contains(right_child_id) {
+                continue;
+            }
+
+            if basic_equal(left_tree, *left_child_id, right_tree, *right_child_id).is_err() {
+                continue;
+            }
+
+            properties_equal(left_tree, *left_child_id, right_tree, *right_child_id)
+                .map_err(|e| e.add_parent(&left_instance.name))?;
+
+            children_equal(left_tree, *left_child_id, right_tree, *right_child_id)
+                .map_err(|e| e.add_parent(&left_instance.name))?;
+
+            found_match = true;
+            right_visited.insert(*right_child_id);
+        }
+
+        if !found_match {
+            let left_child = left_tree.get_instance(*left_child_id).unwrap();
+
+            return Err(TreeMismatch::new(&left_child.name, "Had no equal in right tree"));
+        }
+    }
+
+    Ok(())
+}