Add Python development compatibility flag for tests

src/workerd/io/compatibility-date.c++

@@ -356,4 +356,11 @@ kj::Maybe<PythonSnapshotRelease::Reader> getPythonSnapshotRelease(
   return result;
 }
 
+kj::String getPythonBundleName(PythonSnapshotRelease::Reader pyodideRelease) {
+  if (pyodideRelease.getPyodide() == "dev") {
+    return kj::str("dev");
+  }
+  return kj::str(pyodideRelease.getPyodide(), "_", pyodideRelease.getPyodideRevision(), "_", pyodideRelease.getBackport());
+}
+
 }  // namespace workerd

src/workerd/io/compatibility-date.capnp

@@ -424,12 +424,20 @@ struct CompatibilityFlags @0x8f8c1b68151b6cef {
   pythonWorkers @43 :Bool
       $compatEnableFlag("python_workers")
       $pythonSnapshotRelease(pyodide = "0.26.0a2", pyodideRevision = "2024-03-01",
-          packages = "2024-03-01", backport = 0);
+          packages = "2024-03-01", backport = 0)
+      $impliedByAfterDate(name = "pythonWorkersDevPyodide", date = "2000-01-01");
   # Enables Python Workers. Access to this flag is not restricted, instead bundles containing
   # Python modules are restricted in EWC.
   #
   # WARNING: Python Workers are still an experimental feature and thus subject to change.
 
+  pythonWorkersDevPyodide @58 :Bool
+    $compatEnableFlag("python_workers_development")
+    $pythonSnapshotRelease(pyodide = "dev", pyodideRevision = "dev",
+          packages = "2024-03-01", backport = 0)
+    $experimental;
+  # Enables Python Workers and uses the bundle from the Pyodide source directory directly. For testing only.
+
   fetcherNoGetPutDelete @44 :Bool
       $compatEnableFlag("fetcher_no_get_put_delete")
       $compatDisableFlag("fetcher_has_get_put_delete")

src/workerd/io/compatibility-date.h

@@ -52,6 +52,7 @@ kj::String currentDateStr();
 
 kj::Maybe<PythonSnapshotRelease::Reader> getPythonSnapshotRelease(
     CompatibilityFlags::Reader featureFlags);
+kj::String getPythonBundleName(PythonSnapshotRelease::Reader pyodideRelease);
 
 // These values come from src/workerd/io/compatibility-date.capnp
 static constexpr uint64_t COMPAT_ENABLE_FLAG_ANNOTATION_ID = 0xb6dabbc87cd1b03eull;

src/workerd/server/tests/python/BUILD.bazel

@@ -4,14 +4,14 @@ load("//src/workerd/server/tests/python:py_wd_test.bzl", "py_wd_test")
 
 load("@bazel_skylib//rules:copy_file.bzl", "copy_file")
 
-# pyodide-dev.capnp.bin represents a custom pyodide version "dev" that is generated
+# pyodide_dev.capnp.bin represents a custom pyodide version "dev" that is generated
 # at build time using the latest contents of the src/pyodide directory.
 # This is used to run tests to ensure that they are always run against the latest build of
 # the Pyodide bundle.
 copy_file(
-    name = "pyodide-dev.capnp.bin@rule",
+    name = "pyodide_dev.capnp.bin@rule",
     src = "//src/pyodide:pyodide.capnp.bin",
-    out = "pyodide-bundle-cache/pyodide-dev.capnp.bin"
+    out = "pyodide-bundle-cache/pyodide_dev.capnp.bin"
 )
 
 py_wd_test(

src/workerd/server/tests/python/env-param/env.wd-test

@@ -14,7 +14,7 @@ const unitTests :Workerd.Config = (
           ),
         ],
         compatibilityDate = "2024-01-15",
-        compatibilityFlags = ["python_workers"],
+        compatibilityFlags = ["python_workers_development"],
       )
     ),
   ],

src/workerd/server/tests/python/hello/hello.wd-test

@@ -8,7 +8,7 @@ const unitTests :Workerd.Config = (
           (name = "worker.py", pythonModule = embed "worker.py")
         ],
         compatibilityDate = "2024-01-15",
-        compatibilityFlags = ["python_workers"],
+        compatibilityFlags = ["python_workers_development"],
       )
     ),
   ],

src/workerd/server/tests/python/py_wd_test.bzl

@@ -7,8 +7,8 @@ def py_wd_test(
   args = [],
   **kwargs
 ):
-    data += ["pyodide-dev.capnp.bin@rule"]
-    args += ["--pyodide-bundle-disk-cache-dir", "$(location pyodide-dev.capnp.bin@rule)/.."]
+    data += ["pyodide_dev.capnp.bin@rule"]
+    args += ["--pyodide-bundle-disk-cache-dir", "$(location pyodide_dev.capnp.bin@rule)/.."]
 
     wd_test(
         src = src,

src/workerd/server/tests/python/random/random.wd-test

@@ -8,7 +8,7 @@ const unitTests :Workerd.Config = (
           (name = "worker.py", pythonModule = embed "worker.py")
         ],
         compatibilityDate = "2024-01-15",
-        compatibilityFlags = ["python_workers"],
+        compatibilityFlags = ["python_workers_development"],
       )
     ),
   ],

src/workerd/server/tests/python/subdirectory/subdirectory.wd-test

@@ -10,7 +10,7 @@ const unitTests :Workerd.Config = (
           (name = "subdir/a.py", pythonModule = embed "./subdir/a.py"),
         ],
         compatibilityDate = "2023-12-18",
-        compatibilityFlags = ["python_workers"],
+        compatibilityFlags = ["python_workers_development"],
       )
     ),
   ],

src/workerd/server/workerd-api.c++

@@ -442,7 +442,7 @@ kj::Maybe<jsg::ModuleRegistry::ModuleInfo> WorkerdApi::tryCompileModule(
 
 namespace {
 kj::Path getPyodideBundleFileName(kj::StringPtr version) {
-  return kj::Path(kj::str("pyodide-", version, ".capnp.bin"));
+  return kj::Path(kj::str("pyodide_", version, ".capnp.bin"));
 }
 
 kj::Maybe<kj::Own<const kj::ReadableFile>> getPyodideBundleFile(
@@ -506,7 +506,7 @@ kj::Maybe<jsg::Bundle::Reader> fetchPyodideBundle(const api::pyodide::PythonConf
 
       kj::HttpHeaders headers(table);
 
-      kj::String url = kj::str("https://pyodide.runtime-playground.workers.dev/pyodide-capnp-bin/pyodide-", version, ".capnp.bin");
+      kj::String url = kj::str("https://pyodide.runtime-playground.workers.dev/pyodide-capnp-bin/pyodide_", version, ".capnp.bin");
 
       auto req = client->request(kj::HttpMethod::GET, kj::StringPtr(url), headers);
 
@@ -541,18 +541,10 @@ void WorkerdApi::compileModules(
           "The python_workers compatibility flag is required to use Python.");
       // Inject Pyodide bundle
       if(util::Autogate::isEnabled(util::AutogateKey::PYODIDE_LOAD_EXTERNAL)) {
-          KJ_IF_SOME(bundle, fetchPyodideBundle(impl->pythonConfig, "dev"_kj)) {
-            modules->addBuiltinBundle(bundle, kj::none);
-          } else {
-            auto pythonRelease = KJ_ASSERT_NONNULL(getPythonSnapshotRelease(featureFlags));
-            auto pyodide = pythonRelease.getPyodide();
-            auto pyodideRevision = pythonRelease.getPyodideRevision();
-            auto backport = pythonRelease.getBackport();
-
-            auto version = kj::str(pyodide, "_", pyodideRevision, "_", backport);
-            auto bundle = KJ_ASSERT_NONNULL(fetchPyodideBundle(impl->pythonConfig, version), "Failed to get Pyodide bundle");
-            modules->addBuiltinBundle(bundle, kj::none);
-          }
+          auto pythonRelease = KJ_ASSERT_NONNULL(getPythonSnapshotRelease(featureFlags));
+          auto version = getPythonBundleName(pythonRelease);
+          auto bundle = KJ_ASSERT_NONNULL(fetchPyodideBundle(impl->pythonConfig, version), "Failed to get Pyodide bundle");
+          modules->addBuiltinBundle(bundle, kj::none);
       }
       // Inject pyodide bootstrap module (TODO: load this from the capnproto bundle?)
       {