fix: preserve sitecustomize import with python gunicorn shim

Author: IzaakGough

src/emulator/functionsEmulator.spec.ts

@@ -69,6 +69,7 @@ describe("FunctionsEmulator", () => {
     expect(shim).to.include("PathFinder.find_spec(");
     expect(shim).to.include('"sitecustomize", _firebase_remaining_paths');
     expect(shim).to.include("module_from_spec");
+    expect(shim).to.include('sys.modules["sitecustomize"] = _firebase_user_sitecustomize_module');
     expect(shim).to.include("exec_module");
     expect(logLabeled).to.have.been.calledOnceWith(
       "BULLET",
@@ -156,10 +157,12 @@ describe("FunctionsEmulator", () => {
     expect(log).to.not.have.been.called;
   });
 
-  it("should log a debug message and continue shutdown when shim dir cleanup fails", async () => {
+  it("should recreate the shim dir after cleanup fails with a non-ENOENT error", async () => {
     sandbox.stub(portfinder, "getPortPromise").resolves(9595);
-    sandbox.stub(functionsPython, "runWithVirtualEnv").returns({} as any);
-    sandbox.stub(fs, "mkdtempSync").returns("/tmp/firebase-tools-python-shim-error");
+    const runWithVirtualEnv = sandbox.stub(functionsPython, "runWithVirtualEnv").returns({} as any);
+    const mkdtempSync = sandbox.stub(fs, "mkdtempSync");
+    mkdtempSync.onFirstCall().returns("/tmp/firebase-tools-python-shim-error");
+    mkdtempSync.onSecondCall().returns("/tmp/firebase-tools-python-shim-recreated");
     sandbox.stub(fs, "writeFileSync");
     const rmSync = sandbox.stub(fs, "rmSync").throws(new Error("permission denied"));
 
@@ -168,10 +171,15 @@ describe("FunctionsEmulator", () => {
 
     await (emulator as any).startPython(makePythonBackend(), {});
     await emulator.stop();
+    await (emulator as any).startPython(makePythonBackend(), {});
 
     expect(rmSync).to.have.been.calledOnceWith("/tmp/firebase-tools-python-shim-error", {
       recursive: true,
     });
+    expect(mkdtempSync).to.have.been.calledTwice;
+    expect(runWithVirtualEnv.secondCall.args[2].PYTHONPATH).to.equal(
+      "/tmp/firebase-tools-python-shim-recreated",
+    );
     expect(log).to.have.been.calledWith(
       "DEBUG",
       sinon.match("Failed to clean up python-disable-gunicorn shim dir"),

src/emulator/functionsEmulator.ts

@@ -113,6 +113,7 @@ if (
     _firebase_user_sitecustomize_module = importlib.util.module_from_spec(
         _firebase_user_sitecustomize
     )
+    sys.modules["sitecustomize"] = _firebase_user_sitecustomize_module
     _firebase_user_sitecustomize.loader.exec_module(_firebase_user_sitecustomize_module)
 `;
 
@@ -138,18 +139,17 @@ function cleanupPythonDisableGunicornShimDir(logDebug: (message: string) => void
     return;
   }
 
+  const shimDir = pythonDisableGunicornShimDir;
+  pythonDisableGunicornShimDir = undefined;
+
   try {
-    fs.rmSync(pythonDisableGunicornShimDir, { recursive: true });
-    pythonDisableGunicornShimDir = undefined;
+    fs.rmSync(shimDir, { recursive: true });
   } catch (e: any) {
     if (e?.code === "ENOENT") {
-      pythonDisableGunicornShimDir = undefined;
       return;
     }
 
-    logDebug(
-      `Failed to clean up python-disable-gunicorn shim dir ${pythonDisableGunicornShimDir}: ${e}`,
-    );
+    logDebug(`Failed to clean up python-disable-gunicorn shim dir ${shimDir}: ${e}`);
   }
 }