Add CI workflows

.github/dependabot.yml

@@ -0,0 +1,13 @@
+version: 2
+updates:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    labels: ["dependencies"]
+    schedule:
+      interval: "weekly"
+  - package-ecosystem: "pip"
+    directory: "/"
+    labels: ["dependencies"]
+    versioning-strategy: increase
+    schedule:
+      interval: "monthly"

.github/workflows/README.md

@@ -0,0 +1,23 @@
+# GitHub Actions workflows
+
+This directory contains a number of workflows for use with [GitHub Actions](https://docs.github.com/actions).  They specify what standards should be expected for development of this software, including pull requests.  These workflows are designed to work out of the box for any research software prototype, especially those based on [Qiskit](https://qiskit.org/).
+
+## Lint check (`lint.yml`)
+
+This workflow checks that the code is formatted properly and follows the style guide (`clang-format` and `clang-tidy`).
+
+## Latest version tests (`test_latest_versions.yml`)
+
+This workflow installs the latest version of tox and runs the current repository's tests.
+
+## Documentation (`docs.yml`)
+
+This workflow ensures that the [Sphinx](https://www.sphinx-doc.org/) documentation builds successfully.  It also publishes the resulting build to [GitHub Pages](https://pages.github.com/) if it is from the appropriate branch (e.g., `main`).
+
+## Citation preview (`citation.yml`)
+
+This workflow is only triggered when the `CITATION.bib` file is changed.  It ensures that the file contains only ASCII characters ([escaped codes](https://en.wikibooks.org/wiki/LaTeX/Special_Characters#Escaped_codes) are preferred, as then the `bib` file will work even when `inputenc` is not used).  It also compiles a sample LaTeX document which includes the citation in its bibliography and uploads the resulting PDF as an artifact so it can be previewed (e.g., before merging a pull request).
+
+## Release (`release.yml`)
+
+This workflow is triggered by a maintainer pushing a tag that represents a release.  It publishes the release to github.com.

.github/workflows/citation.yml

@@ -0,0 +1,72 @@
+name: Citation preview
+
+on:
+  push:
+    branches:
+      - main
+      - 'stable/**'
+    paths: ['CITATION.bib', '.github/workflows/citation.yml']
+  pull_request:
+    branches:
+      - main
+      - 'stable/**'
+    paths: ['CITATION.bib', '.github/workflows/citation.yml']
+
+jobs:
+  build-preview:
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@v4
+      - name: Check for non-ASCII characters
+        run: |
+          # Fail immediately if there are any non-ASCII characters in
+          # the BibTeX source.  We prefer "escaped codes" rather than
+          # UTF-8 characters in order to ensure the bibliography will
+          # display correctly even in documents that do not contain
+          # \usepackage[utf8]{inputenc}.
+          if [ -f "CITATION.bib" ]; then
+          python3 -c 'open("CITATION.bib", encoding="ascii").read()'
+          fi
+      - name: Install LaTeX
+        run: |
+          if [ -f "CITATION.bib" ]; then
+          sudo apt-get update
+          sudo apt-get install -y texlive-latex-base texlive-publishers
+          fi
+      - name: Run LaTeX
+        run: |
+          if [ -f "CITATION.bib" ]; then
+          arr=(${GITHUB_REPOSITORY//\// })
+          export REPO=${arr[1]}
+          cat <<- EOF > citation-preview.tex
+          \documentclass[preprint,aps,physrev,notitlepage]{revtex4-2}
+          \usepackage{hyperref}
+          \begin{document}
+          \title{\texttt{$REPO} BibTeX test}
+          \maketitle
+          \noindent
+          \texttt{$REPO}
+          \cite{$REPO}
+          \bibliography{CITATION}
+          \end{document}
+          EOF
+          pdflatex citation-preview
+          fi
+      - name: Run BibTeX
+        run: |
+          if [ -f "CITATION.bib" ]; then
+          bibtex citation-preview
+          fi
+      - name: Re-run LaTeX
+        run: |
+          if [ -f "CITATION.bib" ]; then
+          pdflatex citation-preview
+          pdflatex citation-preview
+          fi
+      - name: Upload PDF
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: citation-preview.pdf
+          path: citation-preview.pdf

.github/workflows/docs.yml

@@ -0,0 +1,76 @@
+name: Sphinx
+
+on:
+  workflow_dispatch:
+  push:
+    tags:
+      - "[0-9]+.[0-9]+.[0-9]+*"
+    branches:
+      - main
+      - 'stable/**'
+  pull_request:
+    branches:
+      - main
+      - 'stable/**'
+
+jobs:
+  build:
+    name: build docs
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.13'
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install tox
+          sudo apt-get update
+          sudo apt-get install -y pandoc doxygen
+      - name: Tell reno to name the upcoming release after the branch we are on
+        shell: bash
+        run: |
+          sed -i.bak -e '/unreleased_version_title:*/d' releasenotes/config.yaml
+          echo unreleased_version_title: \"Upcoming release \(\`\`${GITHUB_REF_NAME}\`\`\)\" >> releasenotes/config.yaml
+      - name: Build docs
+        run: |
+          tox -e docs
+      - name: Upload docs artifact for GitHub Pages
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: docs/_build/html
+
+      # Provide a nicely named artifact that extracts into an
+      # identically named subdirectory.
+      - name: Prepare nice docs artifact for humans
+        if: always()
+        shell: bash
+        run: |
+          mkdir artifact
+          cp -a docs/_build/html artifact/qiskit-addon-utils-htmldocs
+      - name: Upload nice docs artifact
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: qiskit-addon-utils-htmldocs
+          path: ./artifact
+
+  deploy:
+    name: deploy docs
+    if: ${{ github.ref == 'refs/heads/main' }}
+    needs: build
+    permissions:
+      pages: write
+      id-token: write
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4

.github/workflows/lint.yml

@@ -0,0 +1,48 @@
+name: Lint
+
+on:
+  push:
+    branches:
+      - main
+      - 'stable/**'
+  pull_request:
+    branches:
+      - main
+      - 'stable/**'
+
+jobs:
+  lint:
+    name: lint check
+    runs-on: ubuntu-latest
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+          fetch-depth: 0
+      - name: Set up Python 3.13
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.13'
+      - name: Enable LLVM ppa
+        shell: bash
+        run: |
+          wget -qO- https://apt.llvm.org/llvm-snapshot.gpg.key | sudo tee /etc/apt/trusted.gpg.d/apt.llvm.org.asc
+          cat <<EOF | sudo tee -a /etc/apt/sources.list
+          deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-21 main
+          deb-src http://apt.llvm.org/jammy/ llvm-toolchain-jammy-21 main
+          EOF
+      - name: Install via apt-get
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y fd-find clang-tidy-21 clang-format-21
+          sudo ln -fs clang-format-21 /usr/bin/clang-format
+          sudo ln -fs clang-tidy-21 /usr/bin/clang-tidy
+          sudo ln -fs /usr/bin/fdfind /usr/local/bin/fd
+      - name: Install tox
+        run: |
+          python -m pip install --upgrade pip
+          pip install tox
+      - name: Run lint check
+        run: |
+          tox -e lintcpp

.github/workflows/release.yml

@@ -0,0 +1,25 @@
+name: Publish release
+
+on:
+  workflow_dispatch:
+  push:
+    tags:
+      - "[0-9]+.[0-9]+.[0-9]+"
+
+jobs:
+
+  github:
+    name: github
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout tag
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.ref_name }}
+      - name: Publish release
+        uses: ghalactic/github-release-from-tag@v5
+        if: github.ref_type == 'tag'
+        with:
+          prerelease: false
+          token: ${{ secrets.GITHUB_TOKEN }}
+          generateReleaseNotes: "true"

.github/workflows/test_latest_versions.yml

@@ -0,0 +1,65 @@
+name: Tests
+
+on:
+  push:
+    branches:
+      - main
+      - 'stable/**'
+  pull_request:
+    branches:
+      - main
+      - 'stable/**'
+  schedule:
+    - cron: '0 1 * * *'
+
+jobs:
+  tests:
+    name: latest version tests (${{ matrix.os }}, ${{ matrix.compiler }})
+    runs-on: ${{ matrix.os }}
+    timeout-minutes: 30
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          # Linux x86_64
+          - os: ubuntu-22.04
+            compiler: g++
+          - os: ubuntu-22.04
+            compiler: clang++
+          - os: ubuntu-latest
+            compiler: g++
+          - os: ubuntu-latest
+            compiler: clang++
+          # Linux ARM
+          - os: ubuntu-22.04-arm
+            compiler: g++
+          - os: ubuntu-22.04-arm
+            compiler: clang++
+          # macOS x86_64
+          - os: macos-13
+            compiler: clang++
+          # macOS ARM
+          - os: macos-latest
+            compiler: clang++
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+      - name: Install dependencies
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y g++ clang cmake ninja-build
+      - name: Build
+        shell: bash
+        run: |
+          cmake -S . -B build -G Ninja -DCMAKE_CXX_COMPILER=${{ matrix.compiler }} -DCMAKE_VERBOSE_MAKEFILE:BOOL=ON
+          cmake --build build -j4
+      - name: Run tests
+        shell: bash
+        run: |
+          ./build/sqd_tests
+      - name: Run benchmarks
+        shell: bash
+        run: |
+          ./build/sqd_benchmarks

releasenotes/config.yaml

@@ -0,0 +1,5 @@
+---
+encoding: utf8
+default_branch: main
+unreleased_version_title: "Upcoming release"
+earliest_version: 0.1.0