Use named snapshots for tests

src/snapshots/similar__text__captured_ops.snap

@@ -0,0 +1,22 @@
+---
+source: src/text.rs
+expression: "&diff.ops()"
+---
+[
+    Equal {
+        old_index: 0,
+        new_index: 0,
+        len: 1,
+    },
+    Replace {
+        old_index: 1,
+        old_len: 1,
+        new_index: 1,
+        new_len: 1,
+    },
+    Equal {
+        old_index: 2,
+        new_index: 2,
+        len: 1,
+    },
+]

src/snapshots/similar__text__char_diff.snap

@@ -0,0 +1,39 @@
+---
+source: src/text.rs
+expression: diff.ops()
+---
+[
+    Equal {
+        old_index: 0,
+        new_index: 0,
+        len: 1,
+    },
+    Replace {
+        old_index: 1,
+        old_len: 1,
+        new_index: 1,
+        new_len: 1,
+    },
+    Equal {
+        old_index: 2,
+        new_index: 2,
+        len: 5,
+    },
+    Replace {
+        old_index: 7,
+        old_len: 2,
+        new_index: 7,
+        new_len: 1,
+    },
+    Equal {
+        old_index: 9,
+        new_index: 8,
+        len: 1,
+    },
+    Replace {
+        old_index: 10,
+        old_len: 1,
+        new_index: 9,
+        new_len: 1,
+    },
+]

src/snapshots/similar__text__line_ops.snap

@@ -0,0 +1,42 @@
+---
+source: src/text.rs
+expression: "&changes"
+---
+[
+    Change {
+        tag: Equal,
+        old_index: Some(
+            0,
+        ),
+        new_index: Some(
+            0,
+        ),
+        value: "Hello World\n",
+    },
+    Change {
+        tag: Delete,
+        old_index: Some(
+            1,
+        ),
+        new_index: None,
+        value: "some stuff here\n",
+    },
+    Change {
+        tag: Insert,
+        old_index: None,
+        new_index: Some(
+            1,
+        ),
+        value: "some amazing stuff here\n",
+    },
+    Change {
+        tag: Equal,
+        old_index: Some(
+            2,
+        ),
+        new_index: Some(
+            2,
+        ),
+        value: "some more stuff here\n",
+    },
+]

src/snapshots/similar__text__unified_diff.snap

@@ -0,0 +1,11 @@
+---
+source: src/text.rs
+expression: "&diff.unified_diff(3, Some((\"old\", \"new\")))"
+---
+--- old
++++ new
+@@ -0 +2 @@
+ Hello World
+-some stuff here
++some amazing stuff here
+ some more stuff here