1 files changed, 177 insertions, 0 deletions
diff --git a/browser/components/extensions/test/browser/browser_ext_tabs_autoDiscardable.js b/browser/components/extensions/test/browser/browser_ext_tabs_autoDiscardable.js
new file mode 100644
index 0000000000..74043e2a3a
--- /dev/null
+++ b/browser/components/extensions/test/browser/browser_ext_tabs_autoDiscardable.js
@@ -0,0 +1,177 @@
+"use strict";
+
+add_task(async function test_autoDiscardable() {
+  let files = {
+    "schema.json": JSON.stringify([
+      {
+        namespace: "experiments",
+        functions: [
+          {
+            name: "unload",
+            type: "function",
+            async: true,
+            description:
+              "Unload the least recently used tab using Firefox's built-in tab unloader mechanism",
+            parameters: [],
+          },
+        ],
+      },
+    ]),
+    "parent.js": () => {
+      const { TabUnloader } = ChromeUtils.importESModule(
+        "resource:///modules/TabUnloader.sys.mjs"
+      );
+      const { ExtensionError } = ExtensionUtils;
+      this.experiments = class extends ExtensionAPI {
+        getAPI(context) {
+          return {
+            experiments: {
+              async unload() {
+                try {
+                  await TabUnloader.unloadLeastRecentlyUsedTab(null);
+                } catch (error) {
+                  // We need to do this, otherwise failures won't bubble up to the test properly.
+                  throw ExtensionError(error);
+                }
+              },
+            },
+          };
+        }
+      };
+    },
+  };
+
+  async function background() {
+    let firstTab = await browser.tabs.create({
+      active: false,
+      url: "https://example.org/",
+    });
+
+    // Make sure setting and getting works properly
+    browser.test.assertTrue(
+      firstTab.autoDiscardable,
+      "autoDiscardable should always be true by default"
+    );
+    let result = await browser.tabs.update(firstTab.id, {
+      autoDiscardable: false,
+    });
+    browser.test.assertFalse(
+      result.autoDiscardable,
+      "autoDiscardable should be false after setting it as such"
+    );
+    result = await browser.tabs.update(firstTab.id, {
+      autoDiscardable: true,
+    });
+    browser.test.assertTrue(
+      result.autoDiscardable,
+      "autoDiscardable should be true after setting it as such"
+    );
+    result = await browser.tabs.update(firstTab.id, {
+      autoDiscardable: false,
+    });
+    browser.test.assertFalse(
+      result.autoDiscardable,
+      "autoDiscardable should be false after setting it as such"
+    );
+
+    // Make sure the tab can't be unloaded when autoDiscardable is false
+    await browser.experiments.unload();
+    result = await browser.tabs.get(firstTab.id);
+    browser.test.assertFalse(
+      result.discarded,
+      "Tab should not unload when autoDiscardable is false"
+    );
+
+    // Make sure the tab CAN be unloaded when autoDiscardable is true
+    await browser.tabs.update(firstTab.id, {
+      autoDiscardable: true,
+    });
+    await browser.experiments.unload();
+    result = await browser.tabs.get(firstTab.id);
+    browser.test.assertTrue(
+      result.discarded,
+      "Tab should unload when autoDiscardable is true"
+    );
+
+    // Make sure filtering for discardable tabs works properly
+    result = await browser.tabs.query({ autoDiscardable: true });
+    browser.test.assertEq(
+      2,
+      result.length,
+      "tabs.query should return 2 when autoDiscardable is true "
+    );
+    await browser.tabs.update(firstTab.id, {
+      autoDiscardable: false,
+    });
+    result = await browser.tabs.query({ autoDiscardable: true });
+    browser.test.assertEq(
+      1,
+      result.length,
+      "tabs.query should return 1 when autoDiscardable is false"
+    );
+
+    let onUpdatedPromise = {};
+    onUpdatedPromise.promise = new Promise(
+      resolve => (onUpdatedPromise.resolve = resolve)
+    );
+
+    // Make sure onUpdated works
+    async function testOnUpdatedEvent(autoDiscardable) {
+      browser.test.log(`Testing autoDiscardable = ${autoDiscardable}`);
+      let onUpdated;
+      let promise = new Promise(resolve => {
+        onUpdated = (tabId, changeInfo, tabInfo) => {
+          browser.test.assertEq(
+            firstTab.id,
+            tabId,
+            "The updated tab's ID should match the correct tab"
+          );
+          browser.test.assertDeepEq(
+            { autoDiscardable },
+            changeInfo,
+            "The updated tab's changeInfo should be correct"
+          );
+          browser.test.assertEq(
+            tabInfo.autoDiscardable,
+            autoDiscardable,
+            "The updated tab's tabInfo should be correct"
+          );
+          resolve();
+        };
+      });
+      browser.tabs.onUpdated.addListener(onUpdated, {
+        properties: ["autoDiscardable"],
+      });
+      await browser.tabs.update(firstTab.id, { autoDiscardable });
+      await promise;
+      browser.tabs.onUpdated.removeListener(onUpdated);
+    }
+
+    await testOnUpdatedEvent(true);
+    await testOnUpdatedEvent(false);
+
+    await browser.tabs.remove(firstTab.id); // Cleanup
+    browser.test.notifyPass("autoDiscardable");
+  }
+  let extension = ExtensionTestUtils.loadExtension({
+    isPrivileged: true,
+    manifest: {
+      permissions: ["tabs"],
+      experiment_apis: {
+        experiments: {
+          schema: "schema.json",
+          parent: {
+            scopes: ["addon_parent"],
+            script: "parent.js",
+            paths: [["experiments"]],
+          },
+        },
+      },
+    },
+    background,
+    files,
+  });
+  await extension.startup();
+  await extension.awaitFinish("autoDiscardable");
+  await extension.unload();
+});