1 files changed, 97 insertions, 0 deletions
diff --git a/browser/components/translations/tests/browser/browser_translations_panel_switch_languages.js b/browser/components/translations/tests/browser/browser_translations_panel_switch_languages.js
new file mode 100644
index 0000000000..58bcb212d7
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+++ b/browser/components/translations/tests/browser/browser_translations_panel_switch_languages.js
@@ -0,0 +1,97 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+/**
+ * Tests switching the language.
+ */
+add_task(async function test_translations_panel_switch_language() {
+  const { cleanup, resolveDownloads, runInPage } = await loadTestPage({
+    page: SPANISH_PAGE_URL,
+    languagePairs: LANGUAGE_PAIRS,
+  });
+
+  const { button } = await assertTranslationsButton(
+    { button: true },
+    "The button is available."
+  );
+
+  await runInPage(async TranslationsTest => {
+    const { getH1 } = TranslationsTest.getSelectors();
+    await TranslationsTest.assertTranslationResult(
+      "The page's H1 is in Spanish.",
+      getH1,
+      "Don Quijote de La Mancha"
+    );
+  });
+
+  await waitForTranslationsPopupEvent("popupshown", () => {
+    click(button, "Opening the popup");
+  });
+
+  const translateButton = getByL10nId("translations-panel-translate-button");
+  const fromSelect = getById("translations-panel-from");
+  const toSelect = getById("translations-panel-to");
+
+  ok(!translateButton.disabled, "The translate button starts as enabled");
+  is(fromSelect.value, "es", "The from select starts as Spanish");
+  is(toSelect.value, "en", "The to select starts as English");
+
+  info('Switch from language to "es"');
+  fromSelect.value = "en";
+  fromSelect.dispatchEvent(new Event("command"));
+
+  ok(
+    translateButton.disabled,
+    "The translate button is disabled when the languages are the same"
+  );
+
+  info('Switch from language back to "es"');
+  fromSelect.value = "es";
+  fromSelect.dispatchEvent(new Event("command"));
+
+  ok(
+    !translateButton.disabled,
+    "When the languages are different it can be translated"
+  );
+
+  info("Switch to language to nothing");
+  fromSelect.value = "";
+  fromSelect.dispatchEvent(new Event("command"));
+
+  ok(
+    translateButton.disabled,
+    "The translate button is disabled nothing is selected."
+  );
+
+  info('Switch from language to "en"');
+  fromSelect.value = "en";
+  fromSelect.dispatchEvent(new Event("command"));
+
+  info('Switch to language to "fr"');
+  toSelect.value = "fr";
+  toSelect.dispatchEvent(new Event("command"));
+
+  ok(!translateButton.disabled, "The translate button can now be used");
+
+  await waitForTranslationsPopupEvent("popuphidden", () => {
+    click(
+      translateButton,
+      "Start translating by clicking the translate button."
+    );
+  });
+
+  await resolveDownloads(1);
+
+  await runInPage(async TranslationsTest => {
+    const { getH1 } = TranslationsTest.getSelectors();
+    await TranslationsTest.assertTranslationResult(
+      "The pages H1 is translated using the changed languages.",
+      getH1,
+      "DON QUIJOTE DE LA MANCHA [en to fr, html]"
+    );
+  });
+
+  await cleanup();
+});