zjsunit: Do not run $(...) automatically.

We have generally gone away from using $(...)
initialization in modules that we test with
zjsunit, but there are a few remaining special
cases related to our billing and portico
codebases.

frontend_tests/zjsunit/index.js

@@ -70,6 +70,7 @@ function short_tb(tb) {
 }
 
 function run_one_module(file) {
+    zjquery.clear_initialize_function();
     zjquery.clear_all_elements();
     console.info("running test " + path.basename(file, ".js"));
     test.set_current_file_name(file);

frontend_tests/zjsunit/zjquery.js

@@ -486,13 +486,21 @@ function make_zjquery() {
         return proxy;
     }
 
+    let initialize_function;
+
     const zjquery = function (arg, arg2) {
         if (typeof arg === "function") {
-            // If somebody is passing us a function, we emulate
-            // jQuery's behavior of running this function after
-            // page load time.  But there are no pages to load,
-            // so we just call it right away.
-            arg();
+            if (initialize_function) {
+                throw new Error(`
+                    We are trying to avoid the $(...) mechanism
+                    for initializing modules in our codebase,
+                    and the code that you are compiling/running
+                    has tried to do this twice.  Please either
+                    clean up the real code or reduce the scope
+                    of what you are testing in this test module.
+                `);
+            }
+            initialize_function = arg;
             return undefined;
         }
 
@@ -533,6 +541,14 @@ function make_zjquery() {
         return elems.get(selector);
     };
 
+    zjquery.get_initialize_function = function () {
+        return initialize_function;
+    };
+
+    zjquery.clear_initialize_function = function () {
+        initialize_function = undefined;
+    };
+
     zjquery.create = function (name, opts) {
         assert(!elems.has(name), "You already created an object with this name!!");
         const elem = new_elem(name, opts);