refactor: add backend support + cancellation and batched PBS query

.pre-commit-config.yaml

@@ -49,6 +49,7 @@ repos:
         args: [src, tests, examples]
         additional_dependencies:
           - typer
+          - pytest
   - repo: https://github.com/scientific-python/cookie
     rev: 2024.04.23
     hooks:

CHANGELOG.md

@@ -7,16 +7,31 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased](https://github.com/MaterialsPhysicsANU/pbspy/compare/v0.0.9...HEAD)
 
-### Removed
+### Added
 
-- Remove `progress` parameter from the `wait[_all]` and `result[_all]` methods of `Job`
-  - These methods no longer print job IDs or progress
-- Remove `rich` dependency
+- Add the public `Backend` interface and default `LocalBackend` implementation
+  - `JobDescription.submit()` accepts a backend supplied by the caller
+  - Each `Job` retains its backend for waiting, result retrieval, and cancellation
+- Add `Job.cancel()`
+- Add batched PBS state-query and deletion helpers
+
+### Changed
+
+- Group `Job.wait_all()` and `Job.result_all()` calls by backend so each backend can wait for its jobs together
+- Reuse a shared `LocalBackend` for jobs submitted without an explicit backend
+- Return `None` when PBS has not reported a completed job's exit status
 
 ### Fixed
 
+- Preserve `JobDescription.output_path` and `error_path` on submitted jobs and use them when retrieving results
+- Treat cancellation of finished or unknown PBS jobs as successful
 - Update `JOBFS` limit for jobs on the `copyq` queue of the `Gadi` supercomputer
 
+### Removed
+
+- Remove progress display from the `Job` wait and result methods
+- Remove `rich` dependency
+
 ## [0.0.9](https://github.com/MaterialsPhysicsANU/pbspy/releases/tag/v0.0.9) - 2026-05-18
 
 ### Added

README.md

@@ -12,6 +12,8 @@ See the [documentation](https://MaterialsPhysicsANU.github.io/pbspy/) for more i
 
 ## Example
 
+### Running directly on a supercomputer login-node
+
 ```python
 from pbspy import Job, JobDescription
 
@@ -38,23 +40,12 @@ print("job_a:", result_a.output.strip())
 print("job_b:", result_b.output.strip())
 ```
 
-Output (partially executed):
-
-```text
-✓ 124397435.gadi-pbs job_a
-0:01:15 124397436.gadi-pbs job_b
-```
-
-Output (completed):
-
-```text
-✓ 124397435.gadi-pbs job_a
-✓ 124397436.gadi-pbs job_b
+### Backends
 
-job_a: A
-job_b: B
-```
+PBS operations use `LocalBackend` by default and run on the current host.
+`JobDescription.submit()` also accepts any implementation of the public `Backend`
+interface, allowing alternate execution mechanisms to live in separate packages.
 
-## Licence
+## License
 
 `pbspy` is licensed under the MIT License [LICENSE](./LICENSE) or <http://opensource.org/licenses/MIT>.

pyproject.toml

@@ -21,7 +21,6 @@ license = {text = "MIT License"}
 dependencies = [
 ]
 
-
 [dependency-groups]
 dev = [
     "mypy>=1.14.1",