Add GitHub Action for testing (#1)

* Add GitHub Action for testing

* Don't rely on as_integer_ratio - it doesn't exist for Fractions in Python < 3.8

Author: mdickinson

.github/workflows/python-package.yml

@@ -0,0 +1,37 @@
+# This workflow will install Python dependencies, run tests and lint with a variety of Python versions
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions
+
+name: Python package
+
+on:
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ['3.6', '3.7', '3.8', '3.9']
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        python -m pip install flake8 pytest
+        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+    - name: Lint with flake8
+      run: |
+        # stop the build if there are Python syntax errors or undefined names
+        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+        # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+        flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+    - name: Test with pytest
+      run: |
+        pytest

simplefractions/__init__.py

@@ -49,10 +49,12 @@ def _to_integer_ratio(x):
     """
     if x == math.inf:
         return 1, 0
-    elif x == -math.inf:
+    if x == -math.inf:
         return -1, 0
-    else:
-        return x.as_integer_ratio()
+
+    # Best effort to get a numerator and denominator from x.
+    fx = fractions.Fraction(x)
+    return fx.numerator, fx.denominator
 
 
 def _esb_path(x, side):