| --- |
| license: mit |
| task_categories: |
| - text-generation |
| tags: |
| - code |
| - java |
| - refactoring |
| - benchmark |
| - software-engineering |
| size_categories: |
| - n<1K |
| dataset_info: |
| features: |
| - name: instance_id |
| dtype: string |
| - name: repo |
| dtype: string |
| - name: resource_tier |
| dtype: string |
| - name: repo_stars |
| dtype: float64 |
| - name: repo_forks |
| dtype: float64 |
| - name: language |
| dtype: string |
| - name: base_commit |
| dtype: string |
| - name: merge_commit |
| dtype: string |
| - name: refactoring_types |
| list: string |
| - name: refactoring_descriptions |
| list: string |
| - name: file_path |
| dtype: string |
| - name: source_code_before |
| dtype: string |
| - name: source_code_after |
| dtype: string |
| - name: diff |
| dtype: string |
| - name: is_pure_refactoring |
| dtype: bool |
| - name: compile_before |
| dtype: bool |
| - name: compile_after |
| dtype: bool |
| - name: tests_pass_before |
| dtype: bool |
| - name: tests_pass_after |
| dtype: bool |
| - name: FAIL_TO_PASS |
| list: string |
| - name: PASS_TO_PASS |
| list: string |
| - name: created_at |
| dtype: string |
| - name: repo_license |
| dtype: string |
| - name: lines_changed |
| dtype: float64 |
| splits: |
| - name: test |
| num_bytes: 279451236 |
| num_examples: 816 |
| download_size: 245967508 |
| dataset_size: 279451236 |
| configs: |
| - config_name: default |
| data_files: |
| - split: test |
| path: data/test-* |
| --- |
| |
| # CS4570 Java Refactoring Benchmark |
|
|
| A benchmark of Java refactoring commits mined from GitHub repositories, split into **high-resource** and **low-resource** tiers based on repository popularity. Built for the TU Delft CS4570 ML for Software Engineering course (2026). |
|
|
| ## Dataset split |
|
|
| | Tier | Repositories | Instances | Star range | |
| |------|-------------|-----------|------------| |
| | High-resource | 57 | 618 | 1000-7298 | |
| | Low-resource | ~60 | 198 | 13-90 | |
| | **Total** | | **816** | | |
|
|
| Use the `resource_tier` field to filter by tier. `repo_stars` and `repo_forks` are included for fine-grained popularity analysis. |
|
|
| ## Construction |
|
|
| Each instance is a single-file refactoring commit that was: |
|
|
| 1. Detected by **RefactoringMiner 3.1.3** as containing at least one Java refactoring operation |
| 2. Verified by building the project before and after the commit using Docker (Maven/Gradle, JDK 17/21) |
| 3. Filtered to commits where the project compiles and tests pass both before and after (pure refactorings) |
|
|
| High-resource repos have >=1000 stars and >=10 contributors; low-resource repos have <100 stars. |
|
|
| ## Fields |
|
|
| | Field | Type | Description | |
| |-------|------|-------------| |
| | `instance_id` | string | Unique identifier | |
| | `repo` | string | owner/repo identifier | |
| | `resource_tier` | string | "high" or "low" | |
| | `repo_stars` | int or null | GitHub star count at collection time | |
| | `repo_forks` | int or null | GitHub fork count at collection time | |
| | `language` | string | Always "java" | |
| | `base_commit` | string | Parent commit SHA | |
| | `merge_commit` | string | Refactoring commit SHA | |
| | `refactoring_types` | list[str] | Refactoring type labels from RefactoringMiner | |
| | `refactoring_descriptions` | list[str] or null | Human-readable descriptions (HR only) | |
| | `file_path` | string | Java file path that was refactored | |
| | `source_code_before` | string | File content at base commit | |
| | `source_code_after` | string | File content at merge commit | |
| | `diff` | string | Unified diff between before and after | |
| | `is_pure_refactoring` | bool or null | True if only refactoring operations changed | |
| | `compile_before` | bool or null | Project compiled at base commit | |
| | `compile_after` | bool or null | Project compiled at merge commit | |
| | `tests_pass_before` | bool or null | All tests pass at base commit | |
| | `tests_pass_after` | bool or null | All tests pass at merge commit | |
| | `FAIL_TO_PASS` | list[str] | Tests failing before, passing after | |
| | `PASS_TO_PASS` | list[str] | Tests passing both before and after | |
| | `created_at` | string or null | Commit timestamp (ISO 8601) | |
| | `repo_license` | string or null | SPDX license identifier | |
| | `lines_changed` | int or null | Lines changed in the refactoring | |
|
|
| ## Refactoring types |
|
|
| Top types across both tiers: Extract Method, Rename Method, Rename Variable, Rename Parameter, Extract Variable, Inline Variable, Change Variable Type, Add Parameter, Add Method Annotation, Rename Attribute. |
|
|
| 66 unique refactoring types in total. |
|
|
| ## Usage |
|
|
| ```python |
| from datasets import load_dataset |
| |
| ds = load_dataset("Maxros/test", split="test") |
| |
| # Filter by tier |
| hr = ds.filter(lambda x: x["resource_tier"] == "high") |
| lr = ds.filter(lambda x: x["resource_tier"] == "low") |
| ``` |
|
|
| ## Citation |
|
|
| ``` |
| TU Delft CS4570 -- ML for Software Engineering benchmark, 2026. |
| ``` |
|
|
