add cypress new-post spec

frontend/blog_portal/cypress/e2e/new_post_page.cy.ts

@@ -0,0 +1,63 @@
+describe("new post page", function () {
+  beforeEach(function () {
+    cy.resetDb();
+    cy.clearMail();
+    cy.seedConfirmedUser({
+      email: "alice@example.com",
+      displayName: "alice",
+      password: "longenoughpassword",
+    });
+    cy.seedConfirmedUser({
+      email: "bob@example.com",
+      displayName: "bob",
+      password: "longenoughpassword",
+    });
+  });
+
+  it("redirects anonymous visitors to /login", function () {
+    cy.visit("/users/alice/posts/new");
+    cy.location("pathname").should("eq", "/login");
+  });
+
+  it("redirects users away from another user's new-post page", function () {
+    cy.loginViaApi({
+      email: "alice@example.com",
+      password: "longenoughpassword",
+    });
+
+    cy.visit("/users/bob/posts/new");
+    cy.location("pathname").should("eq", "/");
+  });
+
+  it("publishes a post and redirects to the new post page", function () {
+    cy.loginViaApi({
+      email: "alice@example.com",
+      password: "longenoughpassword",
+    });
+
+    cy.visit("/users/alice/posts/new");
+    cy.get('input[type="text"]').type("Hello world");
+    cy.get("textarea").type("This is the body of my first post.");
+    cy.contains("button", "Publish").click();
+
+    cy.location("pathname").should("match", /^\/posts\/\d+$/);
+    cy.contains("h1", "Hello world").should("be.visible");
+    cy.contains(".body", "This is the body of my first post.").should(
+      "be.visible",
+    );
+  });
+
+  it("blocks submission when the title is empty (HTML5 validation)", function () {
+    cy.loginViaApi({
+      email: "alice@example.com",
+      password: "longenoughpassword",
+    });
+
+    cy.visit("/users/alice/posts/new");
+    cy.get("textarea").type("body only");
+    cy.contains("button", "Publish").click();
+
+    cy.location("pathname").should("eq", "/users/alice/posts/new");
+    cy.get('input[type="text"]:invalid').should("exist");
+  });
+});