draft: Prevent lots of empty inline snapshots with --force-update-snapshots without --accept

insta/src/runtime.rs

@@ -667,8 +667,23 @@ pub fn assert_snapshot(
     if pass {
         ctx.cleanup_passing()?;
 
-        if tool_config.force_update_snapshots() {
-            ctx.update_snapshot(new_snapshot)?;
+        if dbg!(tool_config.force_update_snapshots()) {
+            // Inline snapshots currently create lots of files even when they
+            // match. So we don't update them if they fully match.
+            //
+            // Note that there's a check down the stack on whether the files
+            // match for file snapshots; probably we should combine that check
+            // with `matches_fully` and then use a single check for whether we
+            // force update snapshots. Currently the bad user experience is for
+            // inline snapshots only, so that's the check we do here.
+            let matches_fully = dbg!(&ctx.old_snapshot)
+                .as_ref()
+                .map(|x| x.matches_fully(dbg!(&new_snapshot)))
+                .unwrap_or(false);
+            let inline = ctx.snapshot_file.is_none();
+            if !dbg!(matches_fully) || !dbg!(inline) {
+                ctx.update_snapshot(new_snapshot)?;
+            }
         }
     // otherwise print information and update snapshots.
     } else {

insta/src/snapshot.rs

@@ -255,7 +255,12 @@ impl MetaData {
         // snapshot. But we don't know that from here (notably
         // `self.input_file.is_none()` is not a correct approach). Given that
         // `--require-full-match` is experimental and we're working on making
-        // inline & file snapshots more coherent, I'm leaving this as is for now.
+        // inline & file snapshots more coherent, I'm leaving this as is for
+        // now.
+        //
+        // FIXME: for the current issue around `matches_fully` not passing
+        // correctly for inline snapshots, we need to figure that out here and
+        // remove metadata if so.
         if self.assertion_line.is_some() {
             let mut rv = self.clone();
             rv.assertion_line = None;