added cypress e2e test, updated translation strings

cypress/e2e/local-file.cy.ts

@@ -0,0 +1,44 @@
+import { MaputnikDriver } from "./maputnik-driver";
+
+describe("local file", () => {
+  const { when, get } = new MaputnikDriver();
+
+  beforeEach(() => {
+    when.setStyle("");
+  });
+
+  describe("PMTiles", () => {
+    it("valid file loads without error", () => {
+      const fileName = "polygon-z0.pmtiles"; // a small polygon located at Null Island
+
+      const stub = cy.stub();
+      cy.on('window:alert', stub);
+
+      get
+        .bySelector("file", "type")
+        .selectFile(`cypress/fixtures/${fileName}`, { force: true });
+      when.wait(200);
+      cy.then(() => {
+        // eslint-disable-next-line @typescript-eslint/no-unused-expressions
+        expect(stub).to.not.have.been.called;
+      });
+    });
+
+    it("invalid file results in error", () => {
+      const fileName = "example-style.json";
+
+      const stub = cy.stub();
+      cy.on('window:alert', stub);
+
+      get
+        .bySelector("file", "type")
+        .selectFile(`cypress/fixtures/${fileName}`, { force: true });
+      when.wait(200);
+      cy.then(() => {
+        // eslint-disable-next-line @typescript-eslint/no-unused-expressions
+        expect(stub).to.be.called;
+        expect(stub.getCall(0).args[0]).to.contain('File type is not supported');
+      });
+    })
+  });
+});