test: cover CrossJoinExec row metrics across batched inputs

[rgbuilds]

Which issue does this PR close?

Part of #25333 (CrossJoinExec test coverage only).

Rationale for this change

Join metrics can be incorrect without affecting query results. Existing CrossJoinExec tests did not assert build_input_rows or input_rows across different input batch layouts.

What changes are included in this PR?

Adds Rust test coverage that:

• Verifies build_input_rows, input_rows, and output_rows for the existing single-batch case.
• Runs the same 3 × 2 cross join with input batch sizes of 2 and 1.
• Confirms the row metrics remain 3, 2, and 6 regardless of input batching.

This is a test-only change.

What is the testing strategy for this PR?

cargo fmt --check
cargo test -p datafusion-physical-plan --lib joins::cross_join
cargo clippy -p datafusion-physical-plan --all-targets --all-features -- -D warnings

All checks pass locally.

Are there any user-facing changes?

No.

[rgbuilds]

@CuteChuanChuan I picked up the CrossJoinExec portion of #25333 in this PR. Since you outlined the join-metrics test approach, could you take a look at whether these batch-size cases and metric assertions cover what you had in mind? Thanks!

[github-actions]

Thank you for opening this pull request!

Reviewer note: cargo-semver-checks reported the current version number is not SemVer-compatible with the changes in this pull request (compared against the base branch).

Details

     Cloning apache/main
    Building datafusion-physical-plan v55.1.0 (current)
       Built [  36.364s] (current)
     Parsing datafusion-physical-plan v55.1.0 (current)
      Parsed [   0.132s] (current)
    Building datafusion-physical-plan v55.1.0 (baseline)
       Built [  26.260s] (baseline)
     Parsing datafusion-physical-plan v55.1.0 (baseline)
      Parsed [   0.134s] (baseline)
    Checking datafusion-physical-plan v55.1.0 -> v55.1.0 (no change; assume patch)
     Checked [   0.878s] 223 checks: 222 pass, 1 fail, 0 warn, 31 skip

--- failure struct_missing: pub struct removed or renamed ---

Description:
A publicly-visible struct cannot be imported by its prior path. A `pub use` may have been removed, or the struct itself may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.50.0/src/lints/struct_missing.ron

Failed in:
  struct datafusion_physical_plan::TopKDynamicFilters, previously in file /home/runner/work/datafusion/datafusion/target/semver-checks/git-apache_main/91b395bed2ab60801fc19787831bbb6e751d5677/datafusion/physical-plan/src/topk/mod.rs:187

     Summary semver requires new major version: 1 major and 0 minor checks failed
    Finished [  65.560s] datafusion-physical-plan

[kosiew]

@rgbuilds,

Thanks for adding this regression coverage. The new tests verify the cross-join row metrics across different input batch layouts and address the issue requirements. I have one optional suggestion to make the multi-batch setup even more explicit.

[kosiew]

Optional: could we also assert build_input_batches and input_batches, expecting (2, 1) for batch size 2 and (3, 2) for batch size 1? That would ensure future test setup changes do not accidentally remove the multi-batch coverage while keeping the same row totals.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 98.27586% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 82.73%. Comparing base (97c7593) to head (1ff8898).
⚠️ Report is 22 commits behind head on main.

Files with missing lines	Patch %	Lines
datafusion/physical-plan/src/joins/cross_join.rs	98.27%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main   #25530   +/-   ##
=======================================
  Coverage   82.73%   82.73%           
=======================================
  Files        1147     1147           
  Lines      449509   449568   +59     
  Branches   449509   449568   +59     
=======================================
+ Hits       371893   371948   +55     
- Misses      54944    54946    +2     
- Partials    22672    22674    +2     

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[rgbuilds]

@rgbuilds,

Thanks for adding this regression coverage. The new tests verify the cross-join row metrics across different input batch layouts and address the issue requirements. I have one optional suggestion to make the multi-batch setup even more explicit.

Thanks @kosiew for the review and suggestion! I’ve added assertions for both batch metrics to ensure the test continues to cover the intended multi-batch scenarios.

[kosiew]

@rgbuilds,

Thanks for the follow-up. The additional assertions verify that build and probe row counts remain correct across different input batch layouts, while the batch counters reflect the actual number of batches. The changes are limited to tests and address the regression coverage gap.

LGTM!

[kosiew]

🚀
@rgbuilds
Thank you for your contribution.