test: simplify pysr integration test

Author: MilesCranmer

.github/workflows/tests.yml

@@ -78,9 +78,17 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install flake8 pytest pytest-cov nbval numpy virtualenv
+          pip install flake8 pytest pytest-cov nbval numpy
           cp pysrc/juliacall/juliapkg-dev.json pysrc/juliacall/juliapkg.json
           pip install -e .
+      - name: Install integration test dependencies
+        if: ${{ matrix.test-type == 'integration' }}
+        run: |
+          pip install sympy pandas scikit_learn click setuptools
+          # Note that the `--no-deps` flag is needed for ensuring
+          # we avoid installing a newer julicall. The initial `pip install`
+          # is for the non-juliacall dependencies
+          pip install --no-deps pysr
       - name: Lint with flake8
         run: |
           # stop the build if there are Python syntax errors or undefined names

pytest/integration/test_pysr.py

@@ -1,45 +1,17 @@
 def test_integration_pysr():
-    "Integration tests for PySR"
-    import os
-    import platform
-    import subprocess
-    import sys
-    import tempfile
+    "Simple PySR search"
+    import pysr
+    import numpy as np
 
-    with tempfile.TemporaryDirectory() as tempdir:
-        subprocess.run([sys.executable, "-m", "virtualenv", tempdir], check=True)
+    rng = np.random.RandomState(0)
+    X = rng.randn(100, 5)
+    y = np.cos(X[:, 0] * 2.1 - 0.5) + X[:, 1] * 0.7
+    model = pysr.PySRRegressor(
+        niterations=30,
+        unary_operators=["cos"],
+        binary_operators=["*", "+", "-"],
+        early_stop_condition=1e-5,
+    )
+    model.fit(X, y)
+    assert model.equations_.iloc[-1]["loss"] < 1e-5
 
-        virtualenv_path = os.path.join(
-            tempdir, "Scripts" if platform.system() == "Windows" else "bin"
-        )
-        virtualenv_executable = os.path.join(virtualenv_path, "python")
-
-        assert os.path.exists(virtualenv_executable)
-
-        # Install this package
-        subprocess.run([virtualenv_executable, "-m", "pip", "install", "."], check=True)
-        # Install PySR with no requirement on JuliaCall
-        subprocess.run(
-            [virtualenv_executable, "-m", "pip", "install", "--no-deps", "pysr"],
-            check=True,
-        )
-        # Install PySR test requirements
-        subprocess.run(
-            [
-                virtualenv_executable,
-                "-m",
-                "pip",
-                "install",
-                "sympy",
-                "pandas",
-                "scikit_learn",
-                "click",
-                "setuptools",
-                "pytest",
-            ],
-            check=True,
-        )
-        # Run PySR main test suite
-        subprocess.run(
-            [virtualenv_executable, "-m", "pysr", "test", "main"], check=True
-        )