Switch back to using sigterm so that processes can tear down cleanly (microsoft#79)

Author: amcasey

src/utils/execUtils.ts

@@ -121,8 +121,8 @@ function killTree(childProcess: cp.ChildProcessWithoutNullStreams): Promise<void
 
             console.log(`Killing process ${childProcessPid} and its descendents: ${strictDescendentPids.join(", ")}`);
 
-            strictDescendentPids.forEach(pid => process.kill(pid, "SIGKILL"));
-            childProcess.kill("SIGKILL");
+            strictDescendentPids.forEach(pid => process.kill(pid));
+            childProcess.kill();
             // Resolve when we detect that childProcess has closed (above)
         });
     });

src/utils/exerciseServer.ts

@@ -87,6 +87,15 @@ async function exerciseServerWorker(testDir: string, tsserverPath: string, repla
             "--expose-gc",
         ]);
 
+    // You can only wait for kill if the process being killed is the current process's
+    // child, so it's helpful to our caller if we tear down the server.
+    process.once("SIGTERM", async () => {
+        exitExpected = true; // Shouldn't matter, but might as well
+        await server.kill();
+        // This is a sneaky way to invoke node's default SIGTERM handler
+        process.kill(process.pid, "SIGTERM");
+    });
+
     let loadedNewProject = false;
     server.on("event", async (e: any) => {
         switch (e.event) {