A bunch of maintenance

.gitattributes

@@ -1 +1,3 @@
 .git_archival.txt  export-subst
+# SCM syntax highlighting & preventing 3-way merges
+pixi.lock merge=binary linguist-language=YAML linguist-generated=true -diff

.github/renovate.json

@@ -0,0 +1,32 @@
+{
+  "$schema": "https://docs.renovatebot.com/renovate-schema.json",
+  "extends": ["config:recommended"],
+  "dependencyDashboard": true,
+  "schedule": ["on monday"],
+  "managers": [
+    {
+      "managerType": "pixi",
+      "fileMatch": ["(^|/)pyproject\\.toml$"],
+      "lockFileMaintenance": true
+    }
+  ],
+  "lockFileMaintenance": {
+    "enabled": true,
+    "schedule": ["on the first day of the month"],
+    "automerge": true
+  },
+  "packageRules": [
+    {
+      "matchManagers": ["pixi"],
+      "matchUpdateTypes": ["lockFileMaintenance"],
+      "commitMessagePrefix": "chore(pixi):",
+      "labels": ["dependencies", "pixi"]
+    },
+    {
+      "matchManagers": ["github-actions"],
+      "commitMessagePrefix": "chore(ci):",
+      "labels": ["dependencies", "github-actions"],
+      "pinDigests": false
+    }
+  ]
+}

.github/workflows/unit_tests.yml → .github/workflows/ci.yml

@@ -2,12 +2,12 @@ name: unit-tests
 on:
   pull_request:
   push:
-  schedule:
-    - cron: "0 7 * * 1" # Run every Monday at 7:00 UTC
+    branches:
+      - "main"
 
-defaults:
-  run:
-    shell: bash -el {0}
+concurrency:
+  group: branch-${{ github.head_ref }}
+  cancel-in-progress: true
 
 jobs:
   unit-test:
@@ -18,15 +18,10 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v3
-      - name: Setup Conda and parcels
-        uses: ./.github/actions/install-plasticparcels
-        with:
-          environment-file: environment.yml
-          environment-name: py3_parcels
+      - name: Setup pixi
+        uses: prefix-dev/setup-pixi@v0.8.5
       - name: Unit test
-        run: |
-          coverage run -m pytest -v -s tests
-          coverage xml
+        run: pixi run tests with-coverage
       - name: Upload coverage reports to Codecov
         uses: codecov/codecov-action@v4.0.1
         with:

.gitignore

@@ -9,3 +9,9 @@ docs/_build/*
 .vscode
 _version_setup.py
 
+# pixi environments
+.pixi/*
+!.pixi/config.toml
+
+# coverage
+coverage.xml

.readthedocs.yaml

@@ -1,14 +1,18 @@
 version: 2
 build:
-  os: ubuntu-22.04
+  os: ubuntu-lts-latest
   tools:
-    python: mambaforge-22.9
+    # just so RTD stops complaining
+    python: "latest"
   jobs:
-    pre_build:
-      - pip install . # Need access to version information
-
+    create_environment:
+      - asdf plugin add pixi
+      - asdf install pixi latest
+      - asdf global pixi latest
+    install:
+      - pixi install --frozen
+    build:
+      html:
+        - pixi run sphinx-build -T -b html docs $READTHEDOCS_OUTPUT/html
 sphinx:
   configuration: docs/conf.py
-
-conda:
-  environment: docs/environment_docs.yml

CONTRIBUTING.md

@@ -0,0 +1,38 @@
+# Contributing
+
+Contributions are welcome, though please for opinionated changes discuss
+them first in an issue before making a pull request.
+
+## Developer instructions
+
+We use Pixi for our development workflow (a modern alternative to Conda).
+
+- [install Pixi](https://pixi.prefix.dev/latest/installation/)
+- fork and clone the repository, and `cd` into the repository
+- run `pixi task list` (which will show you the available commands for the repository - such as building the documentation, or running tests)
+- run the command you would like using `pixi run ...` (e.g, `pixi run tests`)
+
+You can also enter the environment for the repository by doing `pixi shell` (this is equivalent to `conda activate ...`).
+
+The installation of the virtual environment will be done automatically by Pixi when running `pixi run` or `pixi shell` - this environment is visible in the `./pixi` folder under the repo root.
+
+The `.pixi` folder and the `pixi.lock` file should not be editted by hand. The `pixi.lock` file should be committed.
+
+
+## Maintainer instructions
+
+### About the `pixi.lock`
+
+This repo has a committed `pixi.lock` (meaning that the tree of dependencies used in development is static).
+This results in perfectly reproducibility between dev machines and CI.
+
+This, however, means that releases of dependencies (e.g., deprecations in Parcels or Xarray) may unknowingly break Plasticparcels.
+To mitigate this - there is a Renovate Bot (i.e., an alternative to Dependabot) that will upgrade the Pixi lock on a regular basis and automerge if CI passes.
+If CI fails, there is a change upstream that Plasticparcels needs a code adjustment to deal with.
+
+### Release checklist
+
+- Make sure CI is passing on the latest version of `main`
+- Go to GitHub, draft new release. Enter name of version and "create new tag" if it doesn't already exist. Click "Generate Release Notes". Currate release notes as needed. Look at a previous version release to match the format (title, header, section organisation etc.)
+- Go to [conda-forge/plasticparcels-feedstock](https://github.com/conda-forge/plasticparcels-feedstock), create a new issue (select the "Bot Commands" issue from the menu) with title `@conda-forge-admin, please update version`. This will prompt a build, otherwise there can be a delay in the build.
+  - Approve PR and merge on green