ci: Migrate from CircleCI to GitHub Actions

.github/actions/run-xvfb/action.yml

@@ -0,0 +1,13 @@
+name: 'Run with Xvfb'
+description: 'Run a command under Xvfb with a preconfigured screen size'
+
+inputs:
+  run:
+    description: 'Command to execute'
+    required: true
+
+runs:
+  using: 'composite'
+  steps:
+    - run: xvfb-run --auto-servernum --server-args="-screen 0 1280x1024x24" ${{ inputs.run }}
+      shell: bash

.github/actions/setup-chrome/action.yml

@@ -0,0 +1,25 @@
+name: 'Setup Chrome'
+description: 'Install Chrome and set CHROME_BIN environment variable'
+
+inputs:
+  chrome-version:
+    description: 'Chrome version to install'
+    default: '136.0.7103.113'
+
+runs:
+  using: 'composite'
+  steps:
+    - uses: browser-actions/setup-chrome@4f8e94349a351df0f048634f25fec36c3c91eded # v2
+      id: setup-chrome
+      with:
+        chrome-version: ${{ inputs.chrome-version }}
+
+    - name: Set Chrome binary path
+      run: echo "CHROME_BIN=${{ steps.setup-chrome.outputs.chrome-path }}" >> $GITHUB_ENV
+      shell: bash
+
+    - name: Verify Chrome version
+      run: |
+        echo "Chrome path: $CHROME_BIN"
+        $CHROME_BIN --version
+      shell: bash

.github/actions/setup-image-env/action.yml

@@ -0,0 +1,35 @@
+name: 'Setup Image Environment'
+description: 'Setup Python, uv, and install Kaleido/plotly with required fonts'
+
+inputs:
+  python-version:
+    description: 'Python version to use'
+    default: '3.12'
+  uv-version:
+    description: 'uv version to use'
+    default: '0.11.2'
+
+runs:
+  using: 'composite'
+  steps:
+    - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
+      with:
+        python-version: ${{ inputs.python-version }}
+
+    - name: Install uv
+      uses: astral-sh/setup-uv@37802adc94f370d6bfd71619e3f0bf239e1f3b78 # v7
+      with:
+        version: ${{ inputs.uv-version }}
+
+    - name: Cache apt font packages
+      uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4
+      id: apt-cache
+      with:
+        path: ~/.cache/apt-fonts
+        key: apt-fonts-${{ runner.os }}-${{ hashFiles('.github/scripts/env_image.sh') }}
+
+    - name: Install Kaleido, plotly.io and required fonts
+      run: .github/scripts/env_image.sh
+      shell: bash
+      env:
+        APT_CACHE_HIT: ${{ steps.apt-cache.outputs.cache-hit }}

.github/actions/setup-workspace/action.yml

@@ -0,0 +1,26 @@
+name: 'Setup Workspace'
+description: 'Setup Node.js, install dependencies, and download build artifacts'
+
+inputs:
+  node-version:
+    description: 'Node.js version to use'
+    default: '18'
+
+runs:
+  using: 'composite'
+  steps:
+    - uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6
+      with:
+        node-version: ${{ inputs.node-version }}
+        cache: 'npm'
+
+    - name: Install dependencies
+      run: npm ci
+      shell: bash
+      env:
+        NODE_OPTIONS: '--max-old-space-size=4096'
+
+    - uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8
+      with:
+        name: build-output
+        path: .

.github/fonts/SOURCES.md

@@ -0,0 +1,14 @@
+# Font Sources
+
+These fonts were downloaded from Google Fonts and related repositories for use in image baseline generation during CI. They ensure consistent text rendering across environments.
+
+They can be re-downloaded using the script at `.github/scripts/download_google_fonts.py`.
+
+- **NotoSansMono** (Regular, Bold) — [notofonts/notofonts.github.io](https://cdn.jsdelivr.net/gh/notofonts/notofonts.github.io/fonts/NotoSansMono/hinted/ttf/)
+- **NotoSans** (Regular, Italic, Bold) — [notofonts/notofonts.github.io](https://cdn.jsdelivr.net/gh/notofonts/notofonts.github.io/fonts/NotoSans/hinted/ttf/)
+- **NotoSerif** (Regular, Italic, Bold, BoldItalic) — [notofonts/notofonts.github.io](https://cdn.jsdelivr.net/gh/notofonts/notofonts.github.io/fonts/NotoSerif/hinted/ttf/)
+- **OldStandard** (Regular, Italic, Bold) — [google/fonts](https://raw.githubusercontent.com/google/fonts/refs/heads/main/ofl/oldstandardtt/)
+- **PT Sans Narrow** (Regular, Bold) — [google/fonts](https://raw.githubusercontent.com/google/fonts/refs/heads/main/ofl/ptsansnarrow/)
+- **Raleway** (Regular, Regular-Italic, Bold, Bold-Italic) — [impallari/Raleway](https://raw.githubusercontent.com/impallari/Raleway/refs/heads/master/fonts/v3.000%20Fontlab/TTF/)
+- **Roboto** (Regular, Italic, Bold, BoldItalic) — [googlefonts/roboto-2](https://raw.githubusercontent.com/googlefonts/roboto-2/refs/heads/main/src/hinted/)
+- **GravitasOne** (400Regular) — [expo/google-fonts](https://raw.githubusercontent.com/expo/google-fonts/refs/heads/main/font-packages/gravitas-one/400Regular/)

.github/scripts/env_image.sh

@@ -0,0 +1,36 @@
+#!/bin/sh
+set -e
+
+APT_PACKAGES="fonts-liberation2 fonts-open-sans fonts-noto-cjk fonts-noto-color-emoji fontconfig"
+APT_CACHE_DIR="${HOME}/.cache/apt-fonts"
+
+if [ "$APT_CACHE_HIT" = "true" ] && [ -d "$APT_CACHE_DIR" ]; then
+    echo "Installing font packages from cache..."
+    sudo dpkg -i "$APT_CACHE_DIR"/*.deb 2>/dev/null || sudo apt-get install -yf
+else
+    echo "Downloading and installing font packages..."
+    sudo apt-get update -q
+    sudo apt-get install -y --no-install-recommends $APT_PACKAGES
+    # Save debs for future cache
+    mkdir -p "$APT_CACHE_DIR"
+    for pkg in $APT_PACKAGES; do
+        cp /var/cache/apt/archives/${pkg}_*.deb "$APT_CACHE_DIR/" 2>/dev/null || true
+    done
+fi
+
+# Rebuild font cache
+sudo fc-cache -f
+
+# Install additional fonts (committed in .github/fonts/)
+sudo cp -r .github/fonts/ /usr/share/
+sudo fc-cache -f
+
+# Install Kaleido & Plotly
+uv pip install --system kaleido==0.2.1 plotly==6.6.0 --no-progress
+
+# Install numpy i.e. to convert arrays to typed arrays
+uv pip install --system numpy==2.4.3
+
+# Verify version of python and versions of installed python packages
+python --version
+uv pip freeze --system

.github/scripts/split_files.mjs

@@ -0,0 +1,19 @@
+#!/usr/bin/env node
+
+// Reads lines from stdin and emits only those where index % SHARD_TOTAL == SHARD_INDEX
+// Environment variables SHARD_INDEX and SHARD_TOTAL must be set.
+
+import { readFileSync } from 'fs';
+
+const lines = readFileSync('/dev/stdin', 'utf8').trim().split('\n').filter(Boolean);
+const index = parseInt(process.env.SHARD_INDEX);
+const total = parseInt(process.env.SHARD_TOTAL);
+
+if (isNaN(index) || isNaN(total) || total <= 0) {
+    console.error('SHARD_INDEX and SHARD_TOTAL environment variables must be set to valid integers');
+    process.exit(1);
+}
+
+lines.forEach((line, i) => {
+    if (i % total === index) console.log(line);
+});

.circleci/test.sh → .github/scripts/test.sh

@@ -1,10 +1,13 @@
 #!/bin/bash
 
-# override CircleCi's default run settings
+# GitHub Actions version of .circleci/test.sh
+# Replaces `circleci tests split` with split_files.mjs
+
 set +e
 set +o pipefail
 
-ROOT=$(dirname $0)/..
+ROOT=$(dirname $0)/../..
+SPLIT="$ROOT/.github/scripts/split_files.mjs"
 EXIT_STATE=0
 MAX_AUTO_RETRY=0
 
@@ -33,18 +36,21 @@ retry () {
     fi
 }
 
+# Ensure output directories exist (not present in fresh GHA checkout)
+mkdir -p build/test_images
+
 case $1 in
 
     no-gl-jasmine)
-        SUITE=$(circleci tests glob "$ROOT/test/jasmine/tests/*" | circleci tests split)
+        SUITE=$(ls -1 $ROOT/test/jasmine/tests/* | sort | node "$SPLIT")
         MAX_AUTO_RETRY=2
         retry npm run test-jasmine -- $SUITE --skip-tags=gl,noCI,flaky || EXIT_STATE=$?
 
         exit $EXIT_STATE
         ;;
 
     webgl-jasmine)
-        SHARDS=($(node $ROOT/tasks/shard_jasmine_tests.js --limit=5 --tag=gl | circleci tests split))
+        SHARDS=($(node $ROOT/tasks/shard_jasmine_tests.js --limit=5 --tag=gl | node "$SPLIT"))
         for s in ${SHARDS[@]}; do
             MAX_AUTO_RETRY=2
             retry npm run test-jasmine -- "$s" --tags=gl --skip-tags=noCI --doNotFailOnEmptyTestSuite
@@ -54,7 +60,7 @@ case $1 in
         ;;
 
     virtual-webgl-jasmine)
-        SHARDS=($(node $ROOT/tasks/shard_jasmine_tests.js --limit=5 --tag=gl | circleci tests split))
+        SHARDS=($(node $ROOT/tasks/shard_jasmine_tests.js --limit=5 --tag=gl | node "$SPLIT"))
         for s in ${SHARDS[@]}; do
             MAX_AUTO_RETRY=2
             retry ./node_modules/karma/bin/karma start test/jasmine/karma.conf.js --virtualWebgl --tags=gl --skip-tags=noCI,noVirtualWebgl --doNotFailOnEmptyTestSuite -- "$s"
@@ -64,7 +70,7 @@ case $1 in
         ;;
 
     flaky-no-gl-jasmine)
-        SHARDS=($(node $ROOT/tasks/shard_jasmine_tests.js --limit=1 --tag=flaky | circleci tests split))
+        SHARDS=($(node $ROOT/tasks/shard_jasmine_tests.js --limit=1 --tag=flaky | node "$SPLIT"))
 
         for s in ${SHARDS[@]}; do
             MAX_AUTO_RETRY=5
@@ -96,40 +102,46 @@ case $1 in
         SUITE=$({\
                   find $ROOT/test/image/mocks/gl*     -type f -printf "%f\n"; \
                   find $ROOT/test/image/mocks/map* -type f -printf "%f\n"; \
-                } | sed 's/\.json$//1' | circleci tests split)
-        sudo python3 test/image/make_baseline.py virtual-webgl $SUITE || EXIT_STATE=$?
+                } | sed 's/\.json$//1' | sort | node "$SPLIT")
+        python test/image/make_baseline.py virtual-webgl $SUITE || EXIT_STATE=$?
         exit $EXIT_STATE
         ;;
 
     make-baselines-mathjax3)
-        sudo python3 test/image/make_baseline.py mathjax3    legend_mathjax_title_and_items mathjax parcats_grid_subplots table_latex_multitrace_scatter table_plain_birds table_wrapped_birds ternary-mathjax ternary-mathjax-title-place-subtitle || EXIT_STATE=$?
+        MATHJAX3_MOCKS=$(jq -r '.compare_mathjax3 | join(" ")' test/image/compare_pixels_collections.json)
+        python test/image/make_baseline.py mathjax3 $MATHJAX3_MOCKS || EXIT_STATE=$?
         exit $EXIT_STATE
         ;;
 
     make-baselines-b64)
-        SUITE=$(find $ROOT/test/image/mocks/ -type f -printf "%f\n" | sed 's/\.json$//1' | circleci tests split)
-        sudo python3 test/image/make_baseline.py b64 $SUITE || EXIT_STATE=$?
+        SUITE=$(find $ROOT/test/image/mocks/ -type f -printf "%f\n" | sed 's/\.json$//1' | sort | node "$SPLIT")
+        python test/image/make_baseline.py b64 $SUITE || EXIT_STATE=$?
         exit $EXIT_STATE
         ;;
 
     make-baselines)
-        SUITE=$(find $ROOT/test/image/mocks/ -type f -printf "%f\n" | sed 's/\.json$//1' | circleci tests split)
-        sudo python3 test/image/make_baseline.py $SUITE || EXIT_STATE=$?
+        SUITE=$(find $ROOT/test/image/mocks/ -type f -printf "%f\n" | sed 's/\.json$//1' | sort | node "$SPLIT")
+        python test/image/make_baseline.py $SUITE || EXIT_STATE=$?
+        exit $EXIT_STATE
+        ;;
+
+    make-exports)
+        python test/image/make_exports.py || EXIT_STATE=$?
         exit $EXIT_STATE
         ;;
 
     test-image)
-        node test/image/compare_pixels_test.js || { tar -cvf build/baselines.tar build/test_images/*.png ; exit 1 ; } || EXIT_STATE=$?
+        node test/image/compare_pixels_test.mjs || EXIT_STATE=$?
         exit $EXIT_STATE
         ;;
 
     test-image-mathjax3)
-        node test/image/compare_pixels_test.js mathjax3 || { tar -cvf build/baselines.tar build/test_images/*.png ; exit 1 ; } || EXIT_STATE=$?
+        node test/image/compare_pixels_test.mjs mathjax3 || EXIT_STATE=$?
         exit $EXIT_STATE
         ;;
 
     test-image-virtual-webgl)
-        node test/image/compare_pixels_test.js virtual-webgl || { tar -cvf build/baselines.tar build/test_images/*.png ; exit 1 ; } || EXIT_STATE=$?
+        node test/image/compare_pixels_test.mjs virtual-webgl || EXIT_STATE=$?
         exit $EXIT_STATE
         ;;