add pre-commit

https://pre-commit.com/ is a nice tool that can be installed and used
as git-hook as well as executed as a GitHub Action, unifying how to
validate our development efforts.

Please install pre-commit in your system, then run:

    pre-commit install

See https://pre-commit.com/#install

.github/workflows/ci.yaml

@@ -33,18 +33,10 @@ jobs:
         cache: "poetry"
     - name: "Install poetry dependencies"
       run: "poetry install --no-interaction"
-
-    - name: "Typecheck with MyPy"
-      run: "poetry run mypy"
-
-    - name: "Test with server v2 (reduced < python-3.11)"
-      if: ${{ matrix.python-version != '3.11' }}
-      run: "poetry run python hrana-test-server/server_v2.py pytest --ignore tests/dbapi2 --verbose"
-    - name: "Test with server v2 (full-python-3.11)"
-      if: ${{ matrix.python-version == '3.11' }}
-      run: "poetry run python hrana-test-server/server_v2.py pytest --verbose"  # the dbapi2 tests were copied from python-3.11
-    - name: "Run the readme example"
-      run: "poetry run python examples/readme.py"
-    - name: "Run the books example"
-      run: "poetry run python examples/books.py"
-
+    - run: "pip install pre-commit"
+    - uses: actions/cache@v3
+      with:
+        path: ~/.cache/pre-commit
+        key: pre-commit-3|${{ env.pythonLocation }}|${{ hashFiles('.pre-commit-config.yaml') }}
+    - name: "Run pre-commit"
+      run: pre-commit run --show-diff-on-failure --color=always --hook-stage push

.pre-commit-config.yaml

@@ -0,0 +1,35 @@
+# See https://pre-commit.com for more information
+# See https://pre-commit.com/hooks.html for more hooks
+
+default_install_hook_types: [pre-commit, pre-push, pre-merge-commit]
+
+repos:
+-   repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v1.3.0
+    hooks:
+    -   id: mypy
+        exclude: "^(tests|examples|docs|hrana-test-server)/"
+
+-   repo: local
+    hooks:
+    -   id: run-tests
+        name: run-tests
+        entry: ./scripts/run-tests.sh
+        exclude: ^(examples|docs|hrana-test-server)/
+        language: script
+        pass_filenames: false
+        always_run: true
+        types: [python]
+        stages: [push, merge-commit]
+
+-   repo: local
+    hooks:
+    -   id: run-examples
+        name: run-examples
+        entry: ./scripts/run-examples.sh
+        exclude: ^(tests|docs|hrana-test-server)/
+        language: script
+        pass_filenames: false
+        always_run: true
+        types: [python]
+        stages: [push, merge-commit]

scripts/run-examples.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+export URL="ws://localhost:8080"
+EXAMPLES=(
+    examples/books.py
+    examples/readme.py
+    examples/dbapi2.py
+)
+
+function die() {
+    echo "ERROR: $*" 1>&2
+    exit 1
+}
+
+for e in ${EXAMPLES[@]}; do
+    echo -e "\nEXAMPLE: $e"
+    poetry run \
+        python hrana-test-server/server_v2.py \
+        python $e ||
+            die "failed to execute $e"
+done

scripts/run-tests.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+
+PY_MIN_VER=`python -c "import sys; print(sys.version_info[1])"`
+
+OPTS=("--verbose")
+if [ "$PY_MIN_VER" -lt 11 ]; then
+    # tests/dbapi2 are based on cpython-3.11 test suite
+    OPTS+=("--ignore" "tests/dbapi2")
+fi
+
+set -x
+exec poetry run \
+    python hrana-test-server/server_v2.py \
+    pytest "${OPTS[@]}"