🐛 Don't delete the engine directory every download

The primary justification for this is adding/updating extensions.
Ideally, you should just be able to run `download` again to get
the new extensions, which the current implementation does not
allow for.

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 - Improved error handling and logging for the download command
+- `download`: The `engine/` directory will only be deleted if it is empty. Otherwise it will skip. Justification can be found in [#27](https://github.com/pulse-browser/gluon/issues/27)
 
 ## [1.0.0-rc.2]
 

src/commands/download/firefox.ts

@@ -19,6 +19,7 @@ import {
   unpackAddon,
 } from './addon'
 import { configPath } from '../../utils'
+import { readdir } from 'node:fs/promises'
 
 export function shouldSetupFirefoxSource() {
   return !(
@@ -111,7 +112,7 @@ async function downloadFirefoxSource(version: string) {
 }
 
 export async function downloadInternals(version: string) {
-  // If gFFVersion isn't specified, provide legible error
+  // Provide a legible error if there is no version specified
   if (!version) {
     log.error(
       'You have not specified a version of firefox in your config file. This is required to build a firefox fork.'
@@ -119,9 +120,15 @@ export async function downloadInternals(version: string) {
     process.exit(1)
   }
 
-  if (existsSync(ENGINE_DIR)) {
-    log.info("Deleting engine/")
-    rmSync(ENGINE_DIR)
+  // If the engine directory is empty, we should delete its contents
+  const engineIsEmpty = await readdir(ENGINE_DIR).then((files) => files.length === 0)
+  if (existsSync(ENGINE_DIR) && engineIsEmpty) {
+    log.info("'engine/' is empty, deleting contents...")
+    rmSync(ENGINE_DIR, { recursive: true })
+
+  }
+
+  if (!existsSync(ENGINE_DIR)) {
     await setupFirefoxSource(version)
   }
 

src/commands/update.ts

@@ -1,22 +1,26 @@
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
+import { existsSync, rmSync } from 'node:fs'
 
 import { bin_name, config } from '..'
 import { log } from '../log'
-
 import {
   downloadInternals
 } from './download/firefox'
 import { getLatestFF } from '../utils'
+import { ENGINE_DIR } from '../constants'
 
 export const update = async (): Promise<void> => {
   const version = await getLatestFF(config.version.product)
 
+  // Delete the existing engine directory to download the new version
+  if (existsSync(ENGINE_DIR)) rmSync(ENGINE_DIR, { recursive: true })
+
   await downloadInternals(version)
 
   log.success(
-    `Firefox has sucessfully been updated to ${version}.`,
+    `Firefox has successfully been updated to ${version}.`,
     `You should be ready to make changes to ${config.name}.`,
     '',
     `You should import the patches next, run |${bin_name} import|.`,