feat: add message endpoint, implement e2e test

__tests__/e2e/message.spec.js

@@ -0,0 +1,91 @@
+const uuid = require('uuid');
+const { pgClient, pgClient2 } = require('../../server/infra/database/pgClient');
+
+// test to confrim successful clients' subscription to a postgres channel
+describe('subscribes clients to postgres channel "new_tree_notification" and adds new tree record to confirm subscription', () => {
+    afterAll((done) => { // eslint-disable-line
+        pgClient.end();
+        pgClient2.end();
+        done();
+    })
+
+    // creates two clients and confirms their subscription to a postgres channel
+    it('subscribes two cilents', async () => {
+
+        //  tree object to be added to table
+        const treeObj = {
+            latest_capture_id: uuid.v4(),
+            age: 1
+        }
+
+        // query to create notification function on postgres schema
+        let funQueryRes;
+        try {
+            funQueryRes = await pgClient.query(`CREATE OR REPLACE FUNCTION queue.new_tree_notify_trigger() RETURNS TRIGGER AS $$
+            DECLARE
+            BEGIN
+                PERFORM pg_notify(cast('insert_notification' as text), row_to_json(new)::text);
+                RETURN NEW;
+            END;
+            $$ LANGUAGE plpgsql;`
+            );
+
+        } catch (err) {
+            throw Error(`posgtres function creation error: ${err}`);
+        }
+
+
+        console.log("function created: ", funQueryRes)
+
+        // query to create trigger on postgres table
+        let triggerQueryRes;
+        try {
+            await pgClient.query(`DROP TRIGGER IF EXISTS new_tree_insert_trigger on queue.tree`)
+            triggerQueryRes = await pgClient.query(`CREATE TRIGGER new_tree_insert_trigger BEFORE INSERT ON queue.tree
+            FOR EACH ROW EXECUTE PROCEDURE queue.new_tree_notify_trigger();`)
+        } catch (err) {
+            throw Error(`postgres trigger drop/creation error: ${err}`);
+        }
+
+        console.log("trigger created: ", triggerQueryRes);
+
+        // define action during notification
+        pgClient.on('notification', msg => {
+            const newRow = JSON.parse(msg.payload);
+            expect(newRow).toMatchObject(treeObj); // eslint-disable-line
+        });
+
+        pgClient2.on('notification', msg => {
+            const newRow = JSON.parse(msg.payload);
+            expect(newRow).toMatchObject(treeObj); // eslint-disable-line
+        });
+
+        // subscribe clients to a postgres channel
+        let subscribeQueryRes;
+        try {
+            subscribeQueryRes = await pgClient.query(`LISTEN insert_notification`);
+        } catch (err) {
+            throw Error(`postgres channel subscription error: ${err}`);
+        }
+        console.log("listen notification success: ", subscribeQueryRes);
+        let subscribeQueryRes2;
+        try {
+            subscribeQueryRes2 = await pgClient2.query(`LISTEN insert_notification`);
+        } catch (err) {
+            throw Error(`postgres channel subscription error: ${err}`);
+        }
+        console.log("listen notification success: ", subscribeQueryRes2);
+
+        // insert new row to postgres table
+        const text = `INSERT into queue.tree(latest_capture_id, age) values ($1, $2) RETURNING *`;
+        const values = [treeObj.latest_capture_id, treeObj.age];
+        let insertQueryRes
+        try {
+            insertQueryRes = await pgClient.query(text, values);
+        } catch (err) {
+            throw Error(`postgres row insertion error: ${err}`);
+        }
+        console.log("postgres row insertion success: ", insertQueryRes);
+
+    }, 30000)
+})