tests: add all messages tests

tests/messages/get_messages.ts

@@ -0,0 +1,44 @@
+import { cache, delay, getMessages, sendMessage } from "../../mod.ts";
+import { defaultTestOptions, tempData } from "../ws/start_bot.ts";
+import { assertEquals, assertExists } from "../deps.ts";
+
+Deno.test({
+  name: "[message] fetch messages",
+  async fn() {
+    const message = await sendMessage(tempData.channelId, "Hello World!");
+    const secondMessage = await sendMessage(
+      tempData.channelId,
+      "Hello World 2!",
+    );
+    const thirdMessage = await sendMessage(
+      tempData.channelId,
+      "Hello World 3!",
+    );
+
+    // Assertions
+    assertExists(message);
+    assertExists(secondMessage);
+    assertExists(thirdMessage);
+    // Delay the execution by 5 seconds to allow MESSAGE_CREATE event to be processed
+    await delay(5000);
+    // Make sure the message was created.
+    if (
+      !cache.messages.has(message.id) ||
+      !cache.messages.has(secondMessage.id) ||
+      !cache.messages.has(thirdMessage.id)
+    ) {
+      throw new Error(
+        "The message seemed to be sent but it was not cached.",
+      );
+    }
+
+    // Fetch the messages
+    const fetchedMessages = await getMessages(tempData.channelId, {
+      after: message.id,
+      limit: 2,
+    });
+    // Check if getMessages has worked
+    assertEquals(fetchedMessages.length, 2);
+  },
+  ...defaultTestOptions,
+});