ChunkOrientedStepBuilder throws IllegalArgumentException when retry() is used(configured) without retryLimit()

[KILL9-NO-MERCY]

Hello Spring Batch team,

Thank you for your continued work on Spring Batch. I believe I've found a bug or documentational enhencement in the ChunkOrientedStepBuilder related to retry configuration.

Bug description
When using ChunkOrientedStepBuilder.retry() to specify retryable exceptions without calling retryLimit(), the step builder fails with an IllegalArgumentException during the build phase. This occurs because retryLimit defaults to -1, which is rejected by RetryPolicy.Builder.maxAttempts().

Environment
Spring Batch version: 6.0.0-RC1
Spring Framework version: 7.0.0-RC2

Steps to reproduce
Create a chunk-oriented step using StepBuilder
Call .retry(SomeException.class) without calling .retryLimit()
Attempt to build the step

Expected behavior
The step should build successfully without throwing an exception.

Actual behavior
Exception thrown:

Caused by: java.lang.IllegalArgumentException: Invalid maxAttempts (-1): must be positive or zero for no retry.
	at org.springframework.util.Assert.isTrue(Assert.java:136)
	at org.springframework.core.retry.RetryPolicy.assertMaxAttemptsIsNotNegative(RetryPolicy.java:105)
	at org.springframework.core.retry.RetryPolicy$Builder.maxAttempts(RetryPolicy.java:200)
	at org.springframework.batch.core.step.builder.ChunkOrientedStepBuilder.build(ChunkOrientedStepBuilder.java:404)

Minimal Complete Reproducible example

@Configuration
public class IssueReproductionJobConfiguration {
    @Bean
    public Job issueReproductionJob(JobRepository jobRepository, Step issueReproductionStep) {
        return new JobBuilder(jobRepository)
                .start(issueReproductionStep)
                .build();
    }

    @Bean
    public Step issueReproductionStep(JobRepository jobRepository) {
        AtomicInteger counter = new AtomicInteger(0);

        return new StepBuilder(jobRepository)
                .<String, String>chunk(5)
                .reader(() -> {
                    int count = counter.incrementAndGet();
                    if (count <= 5) {
                        return "kill-" + count;
                    }
                    return null;
                })
                .writer(items -> items.forEach(item ->
                        System.out.println("💀 Terminated: " + item)
                ))
                .faultTolerant()
                .retry(IOException.class)
                //.retryLimit(1)  // ← This must be added for proper operation
                .build();  // ← IllegalArgumentException thrown here
    }
}

Root cause analysis

In ChunkOrientedStepBuilder:

private long retryLimit = -1;  // Default value

public ChunkOrientedStep build() {
    // ...
    if (this.retryPolicy == null) {
        // This condition uses OR, so it's true when only retryableExceptions is set
        if (!this.retryableExceptions.isEmpty() || this.retryLimit > 0) {
            this.retryPolicy = RetryPolicy.builder()
                .maxAttempts(this.retryLimit)  // ← Passes -1 here
                .includes(this.retryableExceptions)
                .build();  // ← Fails here
        }
        else {
            this.retryPolicy = throwable -> false;
        }
    }
    // ...
}

In RetryPolicy.Builder:

public Builder maxAttempts(long maxAttempts) {
    assertMaxAttemptsIsNotNegative(maxAttempts);  // ← Rejects -1
    this.maxAttempts = maxAttempts;
    return this;
}
private static void assertMaxAttemptsIsNotNegative(long maxAttempts) {
    Assert.isTrue(maxAttempts >= 0,
        () -> "Invalid maxAttempts (%d): must be positive or zero for no retry."
              .formatted(maxAttempts));
}

Suggested fixes

Option 1: Change default value

private long retryLimit = 0; // Change from -1 to 0

Option 2: Add documentation

Add JavaDoc to retry() method stating that retryLimit() must be called with a positive value (greater than 0) respectively.

Thank you for reviewing this issue. Please let me know if you need any additional information or clarification.

[fmbenhassine]

Thank you for reporting this valid issue! Similar to #5069, I will change the default value of retry limit as it was in v5 (which is 0).