Use JSON encoding in TestStateMachine setup and clean useless test

internal/statemachine/state_machine_test.go

@@ -277,7 +277,7 @@ func (TestStateMachine *testStateMachine) Setup() error {
 	}
 
 	// if --resume was passed, figure out where to start
-	if err := TestStateMachine.readMetadataGob(); err != nil {
+	if err := TestStateMachine.readMetadataJSON(metadataStateFile); err != nil {
 		return err
 	}
 
@@ -438,21 +438,6 @@ func TestSetCommonOpts(t *testing.T) {
 	})
 }
 
-// TestFailedMetadataParse tests a failure in parsing the metadata file. This is accomplished
-// by giving the state machine a syntactically invalid metadata file to parse
-func TestFailedMetadataParse(t *testing.T) {
-	t.Run("test_failed_metadata_parse", func(t *testing.T) {
-		asserter := helper.Asserter{T: t}
-		var stateMachine StateMachine
-		stateMachine.commonFlags, stateMachine.stateMachineFlags = helper.InitCommonOpts()
-		stateMachine.stateMachineFlags.Resume = true
-		stateMachine.stateMachineFlags.WorkDir = "testdata"
-
-		err := stateMachine.readMetadataGob()
-		asserter.AssertErrContains(err, "failed to parse metadata file")
-	})
-}
-
 // TestParseImageSizes tests a successful image size parse with all of the different allowed syntaxes
 func TestParseImageSizes(t *testing.T) {
 	testCases := []struct {