From 7ca3670338e48bdbb99d2df770056ce57f63f5b8 Mon Sep 17 00:00:00 2001
From: Lucien Greathouse <me@lpghatguy.com>
Date: Tue, 12 Mar 2019 16:23:21 -0700
Subject: [PATCH] Make Imfs ordering deterministic by using BTreeSet

---
 server/src/imfs.rs   | 43 ++++++++++++++++++++++++++++++++++---------
 server/tests/imfs.rs |  8 ++++----
 2 files changed, 38 insertions(+), 13 deletions(-)

diff --git a/server/src/imfs.rs b/server/src/imfs.rs
index c144ae5e..0672ddb1 100644
--- a/server/src/imfs.rs
+++ b/server/src/imfs.rs
@@ -1,9 +1,10 @@
 use std::{
-    collections::{HashMap, HashSet},
-    path::{self, Path, PathBuf},
+    cmp::Ordering,
+    collections::{HashMap, HashSet, BTreeSet},
     fmt,
     fs,
     io,
+    path::{self, Path, PathBuf},
 };
 
 use failure::Fail;
@@ -237,7 +238,7 @@ impl Imfs {
         } else if metadata.is_dir() {
             let item = ImfsItem::Directory(ImfsDirectory {
                 path: path.to_path_buf(),
-                children: HashSet::new(),
+                children: BTreeSet::new(),
             });
 
             self.items.insert(path.to_path_buf(), item);
@@ -285,19 +286,43 @@ impl Imfs {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct ImfsFile {
     pub path: PathBuf,
     pub contents: Vec<u8>,
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
-pub struct ImfsDirectory {
-    pub path: PathBuf,
-    pub children: HashSet<PathBuf>,
+impl PartialOrd for ImfsFile {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
 }
 
-#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+impl Ord for ImfsFile {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.path.cmp(&other.path)
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct ImfsDirectory {
+    pub path: PathBuf,
+    pub children: BTreeSet<PathBuf>,
+}
+
+impl PartialOrd for ImfsDirectory {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl Ord for ImfsDirectory {
+    fn cmp(&self, other: &Self) -> Ordering {
+        self.path.cmp(&other.path)
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
 pub enum ImfsItem {
     File(ImfsFile),
     Directory(ImfsDirectory),
diff --git a/server/tests/imfs.rs b/server/tests/imfs.rs
index 617ce06a..6dc3f49d 100644
--- a/server/tests/imfs.rs
+++ b/server/tests/imfs.rs
@@ -1,5 +1,5 @@
 use std::{
-    collections::{HashMap, HashSet},
+    collections::{HashMap, HashSet, BTreeSet},
     fs,
     path::PathBuf,
 };
@@ -80,7 +80,7 @@ fn base_tree() -> Result<(TempDir, Imfs, ExpectedImfs, TestResources), Error> {
     expected_roots.insert(root.path().to_path_buf());
 
     let root_item = {
-        let mut children = HashSet::new();
+        let mut children = BTreeSet::new();
         children.insert(foo_path.clone());
         children.insert(bar_path.clone());
 
@@ -91,7 +91,7 @@ fn base_tree() -> Result<(TempDir, Imfs, ExpectedImfs, TestResources), Error> {
     };
 
     let foo_item = {
-        let mut children = HashSet::new();
+        let mut children = BTreeSet::new();
         children.insert(baz_path.clone());
 
         ImfsItem::Directory(ImfsDirectory {
@@ -199,7 +199,7 @@ fn adding_folder() -> Result<(), Error> {
     }
 
     let folder_item = {
-        let mut children = HashSet::new();
+        let mut children = BTreeSet::new();
         children.insert(file1_path.clone());
         children.insert(file2_path.clone());