refactor: make Heart.beat() async

This allows us to properly await heart.beat() in our tests and remove
the HACK I added before.

Author: jsjoeio

src/node/heart.ts

@@ -20,20 +20,28 @@ export class Heart {
    * timeout and start or reset a timer that keeps running as long as there is
    * activity. Failures are logged as warnings.
    */
-  public beat(): void {
+  public async beat(): Promise<void> {
     if (this.alive()) {
       return
     }
 
     logger.trace("heartbeat")
-    fs.writeFile(this.heartbeatPath, "").catch((error) => {
+    try {
+      await fs.writeFile(this.heartbeatPath, "")
+    } catch (error: any) {
       logger.warn(error.message)
-    })
+    }
     this.lastHeartbeat = Date.now()
     if (typeof this.heartbeatTimer !== "undefined") {
       clearTimeout(this.heartbeatTimer)
     }
-    this.heartbeatTimer = setTimeout(async () => await heartbeatTimer(this.isActive, this.beat), this.heartbeatInterval)
+    this.heartbeatTimer = setTimeout(async () => {
+      try {
+        await heartbeatTimer(this.isActive, this.beat)
+      } catch (error: any) {
+        logger.warn(error.message)
+      }
+    }, this.heartbeatInterval)
   }
 
   /**

src/node/routes/index.ts

@@ -56,6 +56,8 @@ export const register = async (app: App, args: DefaultedArgs): Promise<Disposabl
     // /healthz|/healthz/ needs to be excluded otherwise health checks will make
     // it look like code-server is always in use.
     if (!/^\/healthz\/?$/.test(req.url)) {
+      // NOTE@jsjoeio - intentionally not awaiting the .beat() call here because
+      // we don't want to slow down the request.
       heart.beat()
     }
 

test/unit/node/heart.test.ts

@@ -43,11 +43,7 @@ describe("Heart", () => {
     expect(fileContents).toBe(text)
 
     heart = new Heart(pathToFile, mockIsActive(true))
-    heart.beat()
-    // HACK@jsjoeio - beat has some async logic but is not an async method
-    // Therefore, we have to create an artificial wait in order to make sure
-    // all async code has completed before asserting
-    await new Promise((r) => setTimeout(r, 100))
+    await heart.beat()
     // Check that the heart wrote to the heartbeatFilePath and overwrote our text
     const fileContentsAfterBeat = await readFile(pathToFile, { encoding: "utf8" })
     expect(fileContentsAfterBeat).not.toBe(text)
@@ -57,15 +53,11 @@ describe("Heart", () => {
   })
   it("should log a warning when given an invalid file path", async () => {
     heart = new Heart(`fakeDir/fake.txt`, mockIsActive(false))
-    heart.beat()
-    // HACK@jsjoeio - beat has some async logic but is not an async method
-    // Therefore, we have to create an artificial wait in order to make sure
-    // all async code has completed before asserting
-    await new Promise((r) => setTimeout(r, 100))
+    await heart.beat()
     expect(logger.warn).toHaveBeenCalled()
   })
-  it("should be active after calling beat", () => {
-    heart.beat()
+  it("should be active after calling beat", async () => {
+    await heart.beat()
 
     const isAlive = heart.alive()
     expect(isAlive).toBe(true)