add tests for runtime config inside py-config and remove usage of indexURL (#734)

* add integration test for py-config

* fix bug

* fix test

* remove indexURL altogether

* make jest happy

* fix create_proxy import

* check that py-config loads an older version

* add unit test

* suggested changes

* don't use /tmp because of bandit

pyscriptjs/tests/integration/test_py_runtime_config.py

@@ -0,0 +1,68 @@
+import os
+import tarfile
+import tempfile
+
+import pytest
+import requests
+
+from .support import PyScriptTest
+
+URL = "https://github.com/pyodide/pyodide/releases/download/0.20.0/pyodide-build-0.20.0.tar.bz2"
+TAR_NAME = "pyodide-build-0.20.0.tar.bz2"
+
+
+@pytest.fixture
+def tar_location(request):
+    val = request.config.cache.get("pyodide-0.20-tar", None)
+    if val is None:
+        response = requests.get(URL, stream=True)
+        TMP_DIR = tempfile.mkdtemp()
+        TMP_TAR_LOCATION = os.path.join(TMP_DIR, TAR_NAME)
+        with open(TMP_TAR_LOCATION, "wb") as f:
+            f.write(response.raw.read())
+        val = TMP_TAR_LOCATION
+        request.config.cache.set("pyodide-0.20-tar", val)
+    return val
+
+
+def unzip(location, extract_to="."):
+    file = tarfile.open(name=location, mode="r:bz2")
+    file.extractall(path=extract_to)
+
+
+class TestRuntimeConfig(PyScriptTest):
+    # The default pyodide version is 0.21.2 as of writing
+    # this test which is newer than the one we are loading below
+    # (after downloading locally) -- which is 0.20.0
+
+    # The test checks if loading a different runtime is possible
+    # and that too from a locally downloaded file without needing
+    # the use of explicit `indexURL` calculation.
+    def test_runtime_config(self, tar_location):
+        unzip(
+            location=tar_location,
+            extract_to=self.tmpdir,
+        )
+
+        self.pyscript_run(
+            snippet="""
+            <py-script>
+                import sys, js
+                pyodide_version = sys.modules["pyodide"].__version__
+                js.console.info("version", pyodide_version)
+                pyodide_version
+            </py-script>
+        """,
+            extra_head="""
+            <py-config>
+                runtimes:
+                - src: "/pyodide/pyodide.js"
+                  name: pyodide-0.20.0
+                  lang: python
+            </py-config>
+        """,
+        )
+
+        assert self.console.info.lines == ["version 0.20.0"]
+        version = self.page.locator("py-script").inner_text()
+        assert version == "0.20.0"