add publish workflow

Author: rmorehig

.github/workflows/publish.yml

@@ -0,0 +1,69 @@
+name: publish
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - pyproject.toml
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    environment:
+      name: pypi
+      url: https://pypi.org/p/tinybird-sdk
+    permissions:
+      contents: read
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Detect version change
+        id: version_check
+        run: |
+          BEFORE_SHA="${{ github.event.before }}"
+          AFTER_SHA="${{ github.sha }}"
+
+          BEFORE_VERSION="$(git show "${BEFORE_SHA}:pyproject.toml" 2>/dev/null | sed -nE 's/^version = "([^"]+)"/\1/p' | head -n1)"
+          AFTER_VERSION="$(sed -nE 's/^version = "([^"]+)"/\1/p' pyproject.toml | head -n1)"
+
+          echo "before_version=${BEFORE_VERSION}" >> "$GITHUB_OUTPUT"
+          echo "after_version=${AFTER_VERSION}" >> "$GITHUB_OUTPUT"
+
+          if [ -z "$AFTER_VERSION" ]; then
+            echo "Could not read current version from pyproject.toml"
+            exit 1
+          fi
+
+          if [ "$BEFORE_VERSION" = "$AFTER_VERSION" ]; then
+            echo "changed=false" >> "$GITHUB_OUTPUT"
+            echo "No version bump detected (${AFTER_VERSION}); skipping publish."
+          else
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+            echo "Version changed: ${BEFORE_VERSION} -> ${AFTER_VERSION}"
+          fi
+
+      - name: Set up Python
+        if: steps.version_check.outputs.changed == 'true'
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.11'
+
+      - name: Install build dependencies
+        if: steps.version_check.outputs.changed == 'true'
+        run: |
+          python -m pip install --upgrade pip
+          python -m pip install build
+
+      - name: Build distributions
+        if: steps.version_check.outputs.changed == 'true'
+        run: python -m build
+
+      - name: Publish package to PyPI
+        if: steps.version_check.outputs.changed == 'true'
+        uses: pypa/gh-action-pypi-publish@release/v1
+        with:
+          password: ${{ secrets.PYPI_TOKEN }}