Fixed an issue with sorting of keys (#304)

src/content/serialization.rs

@@ -50,7 +50,15 @@ impl Content {
     pub(crate) fn sort_maps(&mut self) {
         self.walk(&mut |content| {
             if let Content::Map(ref mut items) = content {
-                items.sort_by(|a, b| a.0.as_key().cmp(&b.0.as_key()));
+                // try to compare by key first, if that fails compare by the
+                // object value.  That way some values normalize, and if we
+                // can't normalize we still have a stable order.
+                items.sort_by(|a, b| match (a.0.as_key(), b.0.as_key()) {
+                    (Key::Other, _) | (_, Key::Other) => {
+                        a.0.partial_cmp(&b.0).unwrap_or(Ordering::Equal)
+                    }
+                    (ref a, ref b) => a.cmp(b),
+                })
             }
             true
         })

tests/snapshots/test_basic__insta_sort_order.snap

@@ -0,0 +1,20 @@
+---
+source: tests/test_basic.rs
+expression: m
+---
+? - 1
+  - 3
+: 4
+? - 1
+  - 4
+: 4
+? - 2
+  - 3
+: 4
+? - 3
+  - 3
+: 4
+? - 9
+  - 3
+: 4
+

tests/test_basic.rs

@@ -3,6 +3,7 @@ use insta::assert_json_snapshot;
 #[cfg(feature = "yaml")]
 use insta::assert_yaml_snapshot;
 use insta::{assert_debug_snapshot, assert_display_snapshot};
+use std::collections::HashMap;
 use std::fmt;
 
 #[test]
@@ -89,3 +90,17 @@ fn test_u128_json() {
     let x: u128 = u128::from(u64::MAX) * 2;
     assert_json_snapshot!(&x, @"36893488147419103230");
 }
+
+#[cfg(feature = "yaml")]
+#[test]
+fn insta_sort_order() {
+    let mut m = HashMap::new();
+    m.insert((1, 3), 4);
+    m.insert((2, 3), 4);
+    m.insert((1, 4), 4);
+    m.insert((3, 3), 4);
+    m.insert((9, 3), 4);
+    insta::with_settings!({sort_maps =>true}, {
+        insta::assert_yaml_snapshot!(m);
+    });
+}