Tidy ups from code review, add section on Detached mode to README.

Author: jeffsmale90

src/packages/cli/src/args.ts

@@ -1,5 +1,4 @@
 import { TruffleColors } from "@ganache/colors";
-
 import yargs, { Options } from "yargs";
 import {
   DefaultFlavor,
@@ -233,7 +232,7 @@ export default function (
             description: highlight(
               "Run Ganache in detached (daemon) mode." +
                 EOL +
-                "See `ganache instances --help` for information omn managing detached instances."
+                "See `ganache instances --help` for information on managing detached instances."
             ),
             type: "boolean",
             alias: ["D", "😈"]

src/packages/cli/src/cli.ts

@@ -9,7 +9,6 @@ import initializeFilecoin from "./initialize/filecoin";
 import type { FilecoinProvider } from "@ganache/filecoin";
 import type { EthereumProvider } from "@ganache/ethereum";
 import {
-  removeDetachedInstanceFile,
   notifyDetachedInstanceReady,
   stopDetachedInstance,
   startDetachedInstance,
@@ -19,18 +18,6 @@ import { TruffleColors } from "@ganache/colors";
 import { table } from "table";
 import chalk from "chalk";
 
-// if process.send is defined, this is a child_process (we assume a detached
-// instance), so we need to notify that we are ready.
-const isDetachedInstance = process.send !== undefined;
-
-if (isDetachedInstance) {
-  // we want to attach this listener as early as possible, to avoid leaving a
-  // dangling instance file
-  process.on("exit", () => {
-    removeDetachedInstanceFile(process.pid);
-  });
-}
-
 const logAndForceExit = (messages: any[], exitCode = 0) => {
   // https://nodejs.org/api/process.html#process_process_exit_code
   // writes to process.stdout in Node.js are sometimes asynchronous and may occur over
@@ -176,6 +163,9 @@ if (argv.action === "start") {
       }
     }
 
+    // if process.send is defined, this is a child_process (we assume a detached
+    // instance), so we need to notify that we are ready.
+    const isDetachedInstance = process.send !== undefined;
     if (isDetachedInstance) {
       notifyDetachedInstanceReady();
     }
@@ -223,7 +213,6 @@ if (argv.action === "start") {
         chalk.bold("Uptime")
       ]
     ];
-
     for (let i = 0; i < instances.length; i++) {
       const instance = instances[i];
 

src/packages/cli/src/detach.ts

@@ -74,8 +74,9 @@ export async function stopDetachedInstance(
       process.kill(instance.pid, "SIGTERM");
     } catch (err) {
       // process.kill throws if the process was not found (or was a group process in Windows)
-      removeDetachedInstanceFile(instance.pid);
       return false;
+    } finally {
+      removeDetachedInstanceFile(instance.pid);
     }
     return true;
   }
@@ -166,17 +167,17 @@ export async function startDetachedInstance(
 /**
  * Fetch all instance of Ganache running in detached mode. Cleans up any
  * instance files for processes that are no longer running.
- * @returns Promise<DetachedInstance[]> resolves with an array of instances
+ * @returns {Promise<DetachedInstance[]>} resolves with an array of instances
  */
 export async function getDetachedInstances(): Promise<DetachedInstance[]> {
   const files = readdirSync(dataPath);
   const instances: DetachedInstance[] = [];
+  const processes = await psList();
 
   for (let i = 0; i < files.length; i++) {
     const filename = files[i];
     const pid = parseInt(filename);
 
-    const processes = await psList();
     const foundProcess = processes.find(p => p.pid === pid);
 
     let shouldRemoveFile = false;
@@ -206,6 +207,8 @@ export async function getDetachedInstances(): Promise<DetachedInstance[]> {
     if (shouldRemoveFile) removeDetachedInstanceFile(pid);
   }
 
+  instances.sort((a, b) => b.startTime - a.startTime);
+
   return instances;
 }
 
@@ -222,7 +225,7 @@ async function findDetachedInstanceByName(
 }
 
 /**
- * Flattens parsed, and namespaced args into an array of arguments to be passed
+ * Flattens parsed and namespaced args into an array of arguments to be passed
  * to a child process. This handles "special" arguments, such as "action",
  * "flavor" and "--detach".
  * @param  {object} args to be flattened

src/packages/ganache/README.md

@@ -470,7 +470,43 @@ Server:
   -p, --server.port, --port             Port to listen on.
                                         deprecated aliases: --port
                                                                                       [number] [default: 8545]
+```
+
+### Detached Instances
+
+Ganache can be started as a background instance via the CLI by providing the following argument (along with any combination
+of the Ganache startup arguments above):
+
+```
+  -D, --detach, --😈                     Run Ganache in detached (daemon) mode.                       [boolean]
+```
+
+This will start Ganache as a background process, and return to the console as soon as Ganache has started and ready to
+receive requests. A friendly name will be returned to STDOUT which can then be used to interact with the instance via
+the `ganache instances` command with the following arguments:
+
+```
+Commands:
+  cli.ts instances list         List instances running in detached mode
+  cli.ts instances stop <name>  Stop the instance specified by <name>
+```
+
+E.g., start Ganache on port 8544, with a block time of 10 seconds, and then stop the instance.
+
+```
+$ ganache --port=8544 --miner.blockTime=10 --detach
+salted_caramel_ganache
+
+$ ganache instances list
+╔═══════╤════════════════════════╤══════════╤═════════╤═══════════╤══════╤════════════╗
+║ PID   │ Name                   │ Flavor   │ Version │ Host      │ Port │ Uptime     ║
+╟───────┼────────────────────────┼──────────┼─────────┼───────────┼──────┼────────────╢
+║ 56004 │ salted_caramel_ganache │ ethereum │ 7.4.3   │ 127.0.0.1 │ 8544 │ 48 seconds ║
+╚═══════╧════════════════════════╧══════════╧═════════╧═══════════╧══════╧════════════╝
+
 
+$ ganache instances stop salted_caramel_ganache
+Process stopped
 ```
 
 ### Ganache Provider Events