1 files changed, 45 insertions, 0 deletions
diff --git a/dom/streams/test/xpcshell/head.js b/dom/streams/test/xpcshell/head.js
new file mode 100644
index 0000000000..510cabe757
--- /dev/null
+++ b/dom/streams/test/xpcshell/head.js
@@ -0,0 +1,45 @@
+"use strict";
+
+const { addDebuggerToGlobal } = ChromeUtils.importESModule(
+  "resource://gre/modules/jsdebugger.sys.mjs"
+);
+
+const SYSTEM_PRINCIPAL = Cc["@mozilla.org/systemprincipal;1"].createInstance(
+  Ci.nsIPrincipal
+);
+
+function addTestingFunctionsToGlobal(global) {
+  global.eval(
+    `
+      const testingFunctions = Cu.getJSTestingFunctions();
+      for (let k in testingFunctions) {
+
+        this[k] = testingFunctions[k];
+      }
+      `
+  );
+  if (!global.print) {
+    global.print = info;
+  }
+  if (!global.newGlobal) {
+    global.newGlobal = newGlobal;
+  }
+  if (!global.Debugger) {
+    addDebuggerToGlobal(global);
+  }
+}
+
+addTestingFunctionsToGlobal(this);
+
+/* Create a new global, with all the JS shell testing functions. Similar to the
+ * newGlobal function exposed to JS shells, and useful for porting JS shell
+ * tests to xpcshell tests.
+ */
+function newGlobal(args) {
+  const global = new Cu.Sandbox(SYSTEM_PRINCIPAL, {
+    freshCompartment: true,
+    ...args,
+  });
+  addTestingFunctionsToGlobal(global);
+  return global;
+}