fix test in module/script modes

test/language/module-code/dynamic-import/eval-self-once-module.js

@@ -11,8 +11,11 @@ info: |
        a. Let requiredModule be ? HostResolveImportedModule(module, required).
        b. Perform ? requiredModule.ModuleEvaluation().
     [...]
+
+    This test is meant to be flagged as module code, it should not initially
+    run as script code or the result will not be the same.
 includes: [fnGlobalObject.js]
-flags: [async]
+flags: [async, module]
 features: [dynamic-import]
 ---*/
 

test/language/module-code/dynamic-import/eval-self-once-script.js

@@ -0,0 +1,38 @@
+// Copyright (C) 2018 Rick Waldron. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+description: Script is evaluated exactly once after loaded by import
+esid: sec-hostimportmoduledynamically
+info: |
+  Success path
+
+  The completion value of any subsequent call to HostResolveImportedModule after
+  FinishDynamicImport has completed, given the arguments referencingScriptOrModule
+  and specifier, must be a module which has already been evaluated, i.e. whose
+  Evaluate concrete method has already been called and returned a normal completion.
+
+  This test is meant to __not__ be flagged as module code, it should not initially
+  run as module code or the result will not be the same.
+includes: [fnGlobalObject.js]
+flags: [async]
+features: [dynamic-import]
+---*/
+
+var global = fnGlobalObject();
+
+if (typeof global.evaluated === 'undefined') {
+  global.evaluated = 0;
+}
+
+global.evaluated++;
+
+Promise.all([
+  import('./eval-self-once-script.js'),
+  import('./eval-self-once-script.js'),
+]).then(async () => {
+  // Use await to serialize imports
+  await import('./eval-self-once-script.js');
+  await import('./eval-self-once-script.js');
+
+  assert.sameValue(global.evaluated, 2, 'global property was defined and incremented only once');
+}).then($DONE, $DONE);