diff --git a/gopls/internal/regtest/workspace_test.go b/gopls/internal/regtest/workspace_test.go
index 9b76436a52..5a4c029a2c 100644
--- a/gopls/internal/regtest/workspace_test.go
+++ b/gopls/internal/regtest/workspace_test.go
@@ -10,6 +10,8 @@ import (
 	"testing"
 
 	"golang.org/x/tools/internal/lsp"
+	"golang.org/x/tools/internal/lsp/fake"
+	"golang.org/x/tools/internal/testenv"
 )
 
 const workspaceProxy = `
@@ -457,3 +459,26 @@ replace b.com => %s/modb
 		}
 	})
 }
+
+func TestNonWorkspaceFileCreation(t *testing.T) {
+	testenv.NeedsGo1Point(t, 13)
+
+	const files = `
+-- go.mod --
+module mod.com
+
+-- x.go --
+package x
+`
+
+	const code = `
+package foo
+import "fmt"
+var _ = fmt.Printf
+`
+	run(t, files, func(t *testing.T, env *Env) {
+		env.CreateBuffer("/tmp/foo.go", "")
+		env.EditBuffer("/tmp/foo.go", fake.NewEdit(0, 0, 0, 0, code))
+		env.GoToDefinition("/tmp/foo.go", env.RegexpSearch("/tmp/foo.go", `Printf`))
+	})
+}
diff --git a/internal/lsp/cache/session.go b/internal/lsp/cache/session.go
index e5978737ce..e74a0d192b 100644
--- a/internal/lsp/cache/session.go
+++ b/internal/lsp/cache/session.go
@@ -430,16 +430,16 @@ func (s *Session) dropView(ctx context.Context, v *View) (int, error) {
 }
 
 func (s *Session) ModifyFiles(ctx context.Context, changes []source.FileModification) error {
-	_, releases, _, err := s.DidModifyFiles(ctx, changes)
+	_, _, releases, _, err := s.DidModifyFiles(ctx, changes)
 	for _, release := range releases {
 		release()
 	}
 	return err
 }
 
-func (s *Session) DidModifyFiles(ctx context.Context, changes []source.FileModification) ([]source.Snapshot, []func(), []span.URI, error) {
+func (s *Session) DidModifyFiles(ctx context.Context, changes []source.FileModification) (map[span.URI]source.View, map[source.View]source.Snapshot, []func(), []span.URI, error) {
 	views := make(map[*View]map[span.URI]source.VersionedFileHandle)
-
+	bestViews := map[span.URI]source.View{}
 	// Keep track of deleted files so that we can clear their diagnostics.
 	// A file might be re-created after deletion, so only mark files that
 	// have truly been deleted.
@@ -447,7 +447,7 @@ func (s *Session) DidModifyFiles(ctx context.Context, changes []source.FileModif
 
 	overlays, err := s.updateOverlays(ctx, changes)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, nil, nil, err
 	}
 	var forceReloadMetadata bool
 	for _, c := range changes {
@@ -455,17 +455,32 @@ func (s *Session) DidModifyFiles(ctx context.Context, changes []source.FileModif
 			forceReloadMetadata = true
 		}
 
-		// Look through all of the session's views, invalidating the file for
-		// all of the views to which it is known.
+		// Build the list of affected views.
+		bestView, err := s.viewOf(c.URI)
+		if err != nil {
+			return nil, nil, nil, nil, err
+		}
+		bestViews[c.URI] = bestView
+
+		var changedViews []*View
 		for _, view := range s.views {
 			// Don't propagate changes that are outside of the view's scope
 			// or knowledge.
 			if !view.relevantChange(c) {
 				continue
 			}
+			changedViews = append(changedViews, view)
+		}
+		// If no view matched the change, assign it to the best view.
+		if len(changedViews) == 0 {
+			changedViews = append(changedViews, bestView)
+		}
+
+		// Apply the changes to all affected views.
+		for _, view := range changedViews {
 			// Make sure that the file is added to the view.
 			if _, err := view.getFile(c.URI); err != nil {
-				return nil, nil, nil, err
+				return nil, nil, nil, nil, err
 			}
 			if _, ok := views[view]; !ok {
 				views[view] = make(map[span.URI]source.VersionedFileHandle)
@@ -480,7 +495,7 @@ func (s *Session) DidModifyFiles(ctx context.Context, changes []source.FileModif
 			} else {
 				fsFile, err := s.cache.getFile(ctx, c.URI)
 				if err != nil {
-					return nil, nil, nil, err
+					return nil, nil, nil, nil, err
 				}
 				fh = &closedFile{fsFile}
 				views[view][c.URI] = fh
@@ -490,18 +505,19 @@ func (s *Session) DidModifyFiles(ctx context.Context, changes []source.FileModif
 			}
 		}
 	}
-	var snapshots []source.Snapshot
+
+	snapshots := map[source.View]source.Snapshot{}
 	var releases []func()
 	for view, uris := range views {
 		snapshot, release := view.invalidateContent(ctx, uris, forceReloadMetadata)
-		snapshots = append(snapshots, snapshot)
+		snapshots[view] = snapshot
 		releases = append(releases, release)
 	}
 	var deletionsSlice []span.URI
 	for uri := range deletions {
 		deletionsSlice = append(deletionsSlice, uri)
 	}
-	return snapshots, releases, deletionsSlice, nil
+	return bestViews, snapshots, releases, deletionsSlice, nil
 }
 
 func (s *Session) updateOverlays(ctx context.Context, changes []source.FileModification) (map[span.URI]*overlay, error) {
diff --git a/internal/lsp/general.go b/internal/lsp/general.go
index 1c0ebf2598..ff76d58dac 100644
--- a/internal/lsp/general.go
+++ b/internal/lsp/general.go
@@ -269,7 +269,7 @@ func (s *Server) addFolders(ctx context.Context, folders []protocol.WorkspaceFol
 // with the previously registered set of directories. If the set of directories
 // has changed, we unregister and re-register for file watching notifications.
 // updatedSnapshots is the set of snapshots that have been updated.
-func (s *Server) updateWatchedDirectories(ctx context.Context, updatedSnapshots []source.Snapshot) error {
+func (s *Server) updateWatchedDirectories(ctx context.Context, updatedSnapshots map[source.View]source.Snapshot) error {
 	dirsToWatch := map[span.URI]struct{}{}
 	seenViews := map[source.View]struct{}{}
 
diff --git a/internal/lsp/source/view.go b/internal/lsp/source/view.go
index 90a5f4d09f..bbe95c4d94 100644
--- a/internal/lsp/source/view.go
+++ b/internal/lsp/source/view.go
@@ -269,7 +269,7 @@ type Session interface {
 
 	// DidModifyFile reports a file modification to the session. It returns the
 	// resulting snapshots, a guaranteed one per view.
-	DidModifyFiles(ctx context.Context, changes []FileModification) ([]Snapshot, []func(), []span.URI, error)
+	DidModifyFiles(ctx context.Context, changes []FileModification) (map[span.URI]View, map[View]Snapshot, []func(), []span.URI, error)
 
 	// Overlays returns a slice of file overlays for the session.
 	Overlays() []Overlay
diff --git a/internal/lsp/text_synchronization.go b/internal/lsp/text_synchronization.go
index 0a781147ee..805393c57e 100644
--- a/internal/lsp/text_synchronization.go
+++ b/internal/lsp/text_synchronization.go
@@ -186,7 +186,7 @@ func (s *Server) didModifyFiles(ctx context.Context, modifications []source.File
 			}()
 		}()
 	}
-	snapshots, releases, deletions, err := s.session.DidModifyFiles(ctx, modifications)
+	views, snapshots, releases, deletions, err := s.session.DidModifyFiles(ctx, modifications)
 	if err != nil {
 		return err
 	}
@@ -201,43 +201,15 @@ func (s *Server) didModifyFiles(ctx context.Context, modifications []source.File
 			return err
 		}
 	}
-	snapshotByURI := make(map[span.URI]source.Snapshot)
-	for _, c := range modifications {
-		snapshotByURI[c.URI] = nil
-	}
-	// Avoid diagnosing the same snapshot twice.
-	snapshotSet := make(map[source.Snapshot][]span.URI)
-	for uri := range snapshotByURI {
-		view, err := s.session.ViewOf(uri)
-		if err != nil {
-			return err
-		}
-		var snapshot source.Snapshot
-		for _, s := range snapshots {
-			if s.View() == view {
-				if snapshot != nil {
-					return errors.New("duplicate snapshots for the same view")
-				}
-				snapshot = s
-			}
-		}
-		// If the file isn't in any known views (for example, if it's in a dependency),
-		// we may not have a snapshot to map it to. As a result, we won't try to
-		// diagnose it. TODO(rstambler): Figure out how to handle this better.
-		if snapshot == nil {
-			continue
-		}
-		snapshotSet[snapshot] = append(snapshotSet[snapshot], uri)
-		snapshotByURI[uri] = snapshot
-	}
 
+	// Check if the user is trying to modify a generated file.
 	for _, mod := range modifications {
 		if mod.OnDisk || mod.Action != source.Change {
 			continue
 		}
-		snapshot, ok := snapshotByURI[mod.URI]
-		if !ok {
-			continue
+		snapshot := snapshots[views[mod.URI]]
+		if snapshot == nil {
+			panic("no snapshot assigned for file " + mod.URI)
 		}
 		// Ideally, we should be able to specify that a generated file should be opened as read-only.
 		// Tell the user that they should not be editing a generated file.
@@ -251,12 +223,17 @@ func (s *Server) didModifyFiles(ctx context.Context, modifications []source.File
 		}
 	}
 
-	for snapshot, uris := range snapshotSet {
+	// Group files by best view and diagnose them.
+	viewURIs := map[source.View][]span.URI{}
+	for uri, view := range views {
+		viewURIs[view] = append(viewURIs[view], uri)
+	}
+	for view, uris := range viewURIs {
 		diagnosticWG.Add(1)
 		go func(snapshot source.Snapshot, uris []span.URI) {
 			defer diagnosticWG.Done()
 			s.diagnoseSnapshot(snapshot, uris)
-		}(snapshot, uris)
+		}(snapshots[view], uris)
 	}
 
 	go func() {
@@ -265,6 +242,7 @@ func (s *Server) didModifyFiles(ctx context.Context, modifications []source.File
 			release()
 		}
 	}()
+
 	// After any file modifications, we need to update our watched files,
 	// in case something changed. Compute the new set of directories to watch,
 	// and if it differs from the current set, send updated registrations.