Guard restore-parameter negative staging

wasm-port/tests/browser/interp_smoke.html

@@ -4446,6 +4446,19 @@
       return { disabledIniPath, iniPath, parameterPath, programPath };
     }
 
+    function generatedParameterPath(wasmPath, expectedWasmPath) {
+      if (wasmPath !== expectedWasmPath) {
+        throw new Error(`browser_parameter_fixture_${expectedWasmPath}_staging: path drift`);
+      }
+      return wasmPath;
+    }
+
+    function writeGeneratedParameterFixture(interp, wasmPath, expectedWasmPath, text) {
+      const checkedPath = generatedParameterPath(wasmPath, expectedWasmPath);
+      interp.writeTextFile(checkedPath, text);
+      return checkedPath;
+    }
+
     async function loadSimMachineFiles(machineRel, iniFile, programFile = null) {
       const iniText = await fetchText(
         `../../vendor/linuxcnc/configs/sim/${machineRel}/${iniFile}`,
@@ -8718,11 +8731,17 @@
 
       verifyExpectedOutput(
         "restore_parameters_missing_file",
-        interp.restoreParameters("/work/browser-missing.var"),
+        interp.restoreParameters(
+          generatedParameterPath("/work/browser-missing.var", "/work/browser-missing.var"),
+        ),
         "restore_parameters=0",
       );
-      const outOfOrderParameterFilePath = "/work/browser-out-of-order.var";
-      interp.writeTextFile(outOfOrderParameterFilePath, "5220 1\n5161 2\n");
+      const outOfOrderParameterFilePath = writeGeneratedParameterFixture(
+        interp,
+        "/work/browser-out-of-order.var",
+        "/work/browser-out-of-order.var",
+        "5220 1\n5161 2\n",
+      );
       verifyExpectedOutput(
         "restore_parameters_out_of_order",
         interp.restoreParameters(outOfOrderParameterFilePath),
@@ -8732,8 +8751,12 @@
         ].join("\n"),
       );
 
-      const missingRequiredParameterFilePath = "/work/browser-missing-required.var";
-      interp.writeTextFile(missingRequiredParameterFilePath, "5161 3.5\n5220 1\n");
+      const missingRequiredParameterFilePath = writeGeneratedParameterFixture(
+        interp,
+        "/work/browser-missing-required.var",
+        "/work/browser-missing-required.var",
+        "5161 3.5\n5220 1\n",
+      );
       verifyExpectedOutput(
         "restore_parameters_missing_required",
         interp.restoreParameters(missingRequiredParameterFilePath),