Flaky test TestOnlineDDLVDiff: add additional check for vreplication …

…workflow to exist (#15695)

Signed-off-by: Rohit Nayak <rohit@planetscale.com>
Signed-off-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>
Co-authored-by: Shlomi Noach <2607934+shlomi-noach@users.noreply.github.com>

go/test/endtoend/vreplication/helper_test.go

@@ -347,6 +347,13 @@ func assertQueryDoesNotExecutesOnTablet(t *testing.T, conn *mysql.Conn, tablet *
 	assert.Equalf(t, count0, count1, "query %q executed in target;\ntried to match %q\nbefore:\n%s\n\nafter:\n%s\n\n", query, matchQuery, body0, body1)
 }
 
+func waitForWorkflowToBeCreated(t *testing.T, vc *VitessCluster, ksWorkflow string) {
+	require.NoError(t, waitForCondition("workflow to be created", func() bool {
+		_, err := vc.VtctlClient.ExecuteCommandWithOutput("Workflow", ksWorkflow, "show")
+		return err == nil
+	}, defaultTimeout))
+}
+
 // waitForWorkflowState waits for all of the given workflow's
 // streams to reach the provided state. You can pass optional
 // key value pairs of the form "key==value" to also wait for

go/test/endtoend/vreplication/vdiff_online_ddl_test.go

@@ -102,7 +102,9 @@ func execOnlineDDL(t *testing.T, strategy, keyspace, query string) string {
 			return false
 		}, defaultTimeout)
 		require.NoError(t, err)
-
+		// The online ddl migration is set to SchemaMigration_RUNNING before it creates the
+		// _vt.vreplication records. Hence wait for the vreplication workflow to be created as well.
+		waitForWorkflowToBeCreated(t, vc, fmt.Sprintf("%s.%s", keyspace, uuid))
 	}
 	return uuid
 }