internal/regtest/misc: fail eagerly in TestRenameFileFromEditor

Updates golang/go#55324

Change-Id: I07cb5465afc7f9e76cad96cb5fbe55e6e16a73b7
Reviewed-on: https://go-review.googlesource.com/c/tools/+/461416
Reviewed-by: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Robert Findley <rfindley@google.com>
gopls-CI: kokoro <noreply+kokoro@google.com>

gopls/internal/regtest/misc/rename_test.go

@@ -413,30 +413,24 @@ package b
 
 		// Moving x.go should make the diagnostic go away.
 		env.RenameFile("a/x.go", "b/x.go")
-		env.Await(
-			OnceMet(
-				env.DoneWithChangeWatchedFiles(),
-				EmptyDiagnostics("a/a.go"),                  // no more duplicate declarations
-				env.DiagnosticAtRegexp("b/b.go", "package"), // as package names mismatch
-			),
+		env.AfterChange(
+			EmptyDiagnostics("a/a.go"),                  // no more duplicate declarations
+			env.DiagnosticAtRegexp("b/b.go", "package"), // as package names mismatch
 		)
 
 		// Renaming should also work on open buffers.
 		env.OpenFile("b/x.go")
 
 		// Moving x.go back to a/ should cause the diagnostics to reappear.
 		env.RenameFile("b/x.go", "a/x.go")
-		// TODO(rfindley): enable using a OnceMet precondition here. We can't
-		// currently do this because DidClose, DidOpen and DidChangeWatchedFiles
-		// are sent, and it is not easy to use all as a precondition.
-		env.Await(
+		env.AfterChange(
 			env.DiagnosticAtRegexp("a/a.go", "X"),
 			env.DiagnosticAtRegexp("a/x.go", "X"),
 		)
 
 		// Renaming the entire directory should move both the open and closed file.
 		env.RenameFile("a", "x")
-		env.Await(
+		env.AfterChange(
 			env.DiagnosticAtRegexp("x/a.go", "X"),
 			env.DiagnosticAtRegexp("x/x.go", "X"),
 		)