Add runtime type check to args passed to setUploadEnabled API

Author: brizental

glean/src/core/glean.ts

@@ -356,6 +356,15 @@ class Glean {
    * @param flag When true, enable metric collection.
    */
   static setUploadEnabled(flag: boolean): void {
+    if (!isBoolean(flag)) {
+      log(
+        LOG_TAG,
+        "Unable to change upload state, new value must be a boolean. Ignoring.",
+        LoggingLevel.Error
+      );
+      return;
+    }
+
     Context.dispatcher.launch(async () => {
       if (!Context.initialized) {
         log(

glean/tests/unit/core/glean.spec.ts

@@ -605,4 +605,18 @@ describe("Glean", function() {
     await Glean.testResetGlean(testAppId, true);
     assert.strictEqual(Context.initialized, true);
   });
+
+  it("setUploadEnabled does nothing in case a non-boolean value is passed to it", async function() {
+    // Set the current upload value to false,
+    // strings are "truthy", this way we can be sure calling with the wrong type dod not work.
+    Glean.setUploadEnabled(false);
+    await Context.dispatcher.testBlockOnQueue();
+    assert.strictEqual(Context.uploadEnabled, false);
+
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore
+    Glean.setUploadEnabled("not a boolean");
+    await Context.dispatcher.testBlockOnQueue();
+    assert.strictEqual(Context.uploadEnabled, false);
+  });
 });