Updated documentation and added unit tests for flow builder priority

Fixes #4456

Author: Robert McNees

spring-batch-core/src/main/java/org/springframework/batch/core/job/flow/support/DefaultStateTransitionComparator.java

@@ -20,7 +20,7 @@
 import java.util.Comparator;
 
 /**
- * Sorts by decreasing specificity of pattern, based on just counting wildcards (with *
+ * Sorts by ascending specificity of pattern, based on just counting wildcards (with *
  * taking precedence over ?). If wildcard counts are equal then falls back to alphabetic
  * comparison. Hence * > foo* > ??? > fo? > foo.
  *

spring-batch-core/src/test/java/org/springframework/batch/core/job/builder/FlowJobBuilderTests.java

@@ -262,6 +262,36 @@ public FlowExecutionStatus decide(JobExecution jobExecution, @Nullable StepExecu
 		assertEquals(1, execution.getStepExecutions().size());
 	}
 
+	@Test
+	void testBuildWithDeciderPriority() {
+		JobExecutionDecider decider = (jobExecution, stepExecution) -> new FlowExecutionStatus("COMPLETED_PARTIALLY");
+		JobFlowBuilder builder = new JobBuilder("flow_priority", jobRepository).start(decider);
+		builder.on("COMPLETED_PARTIALLY").end();
+		builder.on("COMPLETED*").fail();
+		builder.build().preventRestart().build().execute(execution);
+		assertEquals(BatchStatus.COMPLETED, execution.getStatus());
+	}
+
+	@Test
+	void testBuildWithWildcardDeciderPriority() {
+		JobExecutionDecider decider = (jobExecution, stepExecution) -> new FlowExecutionStatus("COMPLETED_PARTIALLY");
+		JobFlowBuilder builder = new JobBuilder("flow_priority", jobRepository).start(decider);
+		builder.on("COMPLETED_?ARTIALLY").end();
+		builder.on("COMPLETED_*ARTIALLY").fail();
+		builder.build().preventRestart().build().execute(execution);
+		assertEquals(BatchStatus.COMPLETED, execution.getStatus());
+	}
+
+	@Test
+	void testBuildWithDeciderPrioritySubstringAndWildcard() {
+		JobExecutionDecider decider = (jobExecution, stepExecution) -> new FlowExecutionStatus("CONTINUABLE");
+		JobFlowBuilder builder = new JobBuilder("flow_priority", jobRepository).start(decider);
+		builder.on("CONTINUABLE").end();
+		builder.on("CONTIN*").fail();
+		builder.build().preventRestart().build().execute(execution);
+		assertEquals(BatchStatus.COMPLETED, execution.getStatus());
+	}
+
 	@Test
 	void testBuildWithIntermediateSimpleJob() {
 		SimpleJobBuilder builder = new JobBuilder("flow", jobRepository).start(step1);