implemented a testcase for mqtt monitors

package.json

@@ -27,7 +27,7 @@
         "build": "vite build --config ./config/vite.config.js",
         "test": "npm run test-backend && npm run test-e2e",
         "test-with-build": "npm run build && npm test",
-        "test-backend": "cross-env TEST_BACKEND=1 node --test test/backend-test",
+        "test-backend": "cross-env TEST_BACKEND=1 node --test test/**/test-*.js",
         "test-e2e": "playwright test --config ./config/playwright.config.js",
         "test-e2e-ui": "playwright test --config ./config/playwright.config.js --ui --ui-port=51063",
         "playwright-codegen": "playwright codegen localhost:3000 --save-storage=./private/e2e-auth.json",
@@ -155,6 +155,7 @@
         "@fortawesome/vue-fontawesome": "~3.0.0-5",
         "@playwright/test": "~1.39.0",
         "@popperjs/core": "~2.10.2",
+        "@testcontainers/hivemq": "^10.13.1",
         "@types/bootstrap": "~5.1.9",
         "@types/node": "^20.8.6",
         "@typescript-eslint/eslint-plugin": "^6.7.5",
@@ -190,6 +191,7 @@
         "stylelint-config-standard": "~25.0.0",
         "terser": "~5.15.0",
         "test": "~3.3.0",
+        "testcontainers": "^10.13.1",
         "typescript": "~4.4.4",
         "v-pagination-3": "~0.1.7",
         "vite": "~5.2.8",

test/backend-test/test-mqtt.js

@@ -0,0 +1,99 @@
+const { describe, test } = require("node:test");
+const assert = require("node:assert");
+const { HiveMQContainer } = require("@testcontainers/hivemq");
+const mqtt = require("mqtt");
+const { MqttMonitorType } = require("../../server/monitor-types/mqtt");
+const { UP, PENDING } = require("../../src/util");
+
+/**
+ * Runs an MQTT test with the
+ * @param  {string} mqttSuccessMessage the message that the monitor expects
+ * @param {null|"keyword"|"json-query"} mqttCheckType the type of check we perform
+ * @param {string} receivedMessage what message is recieved from the mqtt channel
+ * @returns {Promise<Heartbeat>} the heartbeat produced by the check
+ */
+async function testMqtt(mqttSuccessMessage, mqttCheckType, receivedMessage) {
+    const hiveMQContainer = await new HiveMQContainer().start();
+    const connectionString = hiveMQContainer.getConnectionString();
+    const mqttMonitorType = new MqttMonitorType();
+    const monitor = {
+        jsonPath: "firstProp", // always return firstProp for the json-query monitor
+        hostname: connectionString.split(":", 2).join(":"),
+        mqttTopic: "test",
+        port: connectionString.split(":")[2],
+        mqttUsername: null,
+        mqttPassword: null,
+        interval: 20, // controls the timeout
+        mqttSuccessMessage: mqttSuccessMessage, // for keywords
+        expectedValue: mqttSuccessMessage, // for json-query
+        mqttCheckType: mqttCheckType,
+    };
+    const heartbeat = {
+        msg: "",
+        status: PENDING,
+    };
+
+    const testMqttClient = mqtt.connect(hiveMQContainer.getConnectionString());
+    testMqttClient.on("connect", () => {
+        testMqttClient.subscribe("test", (error) => {
+            if (!error) {
+                testMqttClient.publish("test", receivedMessage);
+            }
+        });
+    });
+
+    try {
+        await mqttMonitorType.check(monitor, heartbeat, {});
+    } finally {
+        testMqttClient.end();
+        hiveMQContainer.stop();
+    }
+    return heartbeat;
+}
+
+describe("MqttMonitorType", { concurrency: true }, () => {
+    test("valid keywords (type=default)", async () => {
+        const heartbeat = await testMqtt("KEYWORD", null, "-> KEYWORD <-");
+        assert.strictEqual(heartbeat.status, UP);
+        assert.strictEqual(heartbeat.msg, "Topic: test; Message: -> KEYWORD <-");
+    });
+
+    test("valid keywords (type=keyword)", async () => {
+        const heartbeat = await testMqtt("KEYWORD", "keyword", "-> KEYWORD <-");
+        assert.strictEqual(heartbeat.status, UP);
+        assert.strictEqual(heartbeat.msg, "Topic: test; Message: -> KEYWORD <-");
+    });
+    test("invalid keywords (type=default)", async () => {
+        await assert.rejects(
+            testMqtt("NOT_PRESENT", null, "-> KEYWORD <-"),
+            new Error("Message Mismatch - Topic: test; Message: -> KEYWORD <-"),
+        );
+    });
+
+    test("invalid keyword (type=keyword)", async () => {
+        await assert.rejects(
+            testMqtt("NOT_PRESENT", "keyword", "-> KEYWORD <-"),
+            new Error("Message Mismatch - Topic: test; Message: -> KEYWORD <-"),
+        );
+    });
+    test("valid json-query", async () => {
+        // works because the monitors' jsonPath is hard-coded to "firstProp"
+        const heartbeat = await testMqtt("present", "json-query", "{\"firstProp\":\"present\"}");
+        assert.strictEqual(heartbeat.status, UP);
+        assert.strictEqual(heartbeat.msg, "Message received, expected value is found");
+    });
+    test("invalid (because query fails) json-query", async () => {
+        // works because the monitors' jsonPath is hard-coded to "firstProp"
+        await assert.rejects(
+            testMqtt("[not_relevant]", "json-query", "{}"),
+            new Error("Message received but value is not equal to expected value, value was: [undefined]"),
+        );
+    });
+    test("invalid (because successMessage fails) json-query", async () => {
+        // works because the monitors' jsonPath is hard-coded to "firstProp"
+        await assert.rejects(
+            testMqtt("[wrong_success_messsage]", "json-query", "{\"firstProp\":\"present\"}"),
+            new Error("Message received but value is not equal to expected value, value was: [present]")
+        );
+    });
+});