An incomplete shard snapshot will prevent a shard from moving away from a node (see `SnapshotInProgressAllocationDecider`). That means that when a shard snapshot completes it may become possible to perform some shard movements that previously were not possible, so we should trigger a reroute to start those movements. AFAICT we do not trigger such a reroute today.
test/framework/src/main/java/org/elasticsearch/test/ESTestCase.java
/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */
package org.elasticsearch.test;
import com.carrotsearch.randomizedtesting.RandomizedTest;
import com.carrotsearch.randomizedtesting.annotations.Listeners;
import com.carrotsearch.randomizedtesting.annotations.ThreadLeakFilters;
import com.carrotsearch.randomizedtesting.annotations.ThreadLeakLingering;
import com.carrotsearch.randomizedtesting.annotations.ThreadLeakScope;
import com.carrotsearch.randomizedtesting.annotations.ThreadLeakScope.Scope;
import com.carrotsearch.randomizedtesting.annotations.TimeoutSuite;
import com.carrotsearch.randomizedtesting.generators.CodepointSetGenerator;
import com.carrotsearch.randomizedtesting.generators.RandomNumbers;
import com.carrotsearch.randomizedtesting.generators.RandomPicks;
import com.carrotsearch.randomizedtesting.generators.RandomStrings;
import com.carrotsearch.randomizedtesting.rules.TestRuleAdapter;
import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.Appender;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.LoggerContext;
import org.apache.logging.log4j.core.appender.AbstractAppender;
import org.apache.logging.log4j.core.config.Configurator;
import org.apache.logging.log4j.core.layout.PatternLayout;
import org.apache.logging.log4j.status.StatusConsoleListener;