It works

Even with rimrafall

bin/contained-run-script-sh.js

@@ -0,0 +1,39 @@
+#!/usr/bin/env node
+
+const { spawnSync } = require('child_process');
+const { relative, join } = require('path');
+
+const cwd = process.cwd();
+
+const hostProjectRoot = process.env.INIT_CWD; // TODO maybe throw an `npm prefix` in addition
+const guestProjectRoot = '/home/node-app'
+
+const GUEST_CWD = join(guestProjectRoot, relative(hostProjectRoot, cwd))
+
+console.log(cwd)
+console.log(hostProjectRoot)
+console.log(guestProjectRoot)
+console.log(relative(hostProjectRoot, cwd))
+console.log(GUEST_CWD)
+
+// TODO : if process.argv.slice(2)[1].trim().startsWith('npm '), then execute the command without docker-compose
+
+spawnSync(
+    'docker-compose', 
+    [
+        '-f', '/home/david/projects/containednpm/contained-services.yml', 
+        'run', 'contained_npm_script', 
+        'sh'
+    ].concat(process.argv.slice(2)),
+    {
+        stdio: 'inherit',
+        env: Object.assign(
+            {},
+            process.env, // way too many things here. TODO : clean that up
+            {
+                GUEST_CWD,
+                HOST_CWD: cwd
+            }
+        )
+    }
+)

contained-services.yml

@@ -2,23 +2,13 @@ version: '3'
 services:
   contained_npm_script:
     build: .
-    working_dir: /home/node-app
+    working_dir: "${GUEST_CWD}"
     # Passing the current user id as user id in the container
     user: "${USER_ID}"
     volumes:
         # Current directory as working_dir
-        - ~/projects/containednpm/project-alpha:/home/node-app
-        - ~/projects/containednpm/project-alpha/node_modules:/home/node-app/node_modules
+        - "${INIT_CWD}:/home/node-app:ro"
+        - "${HOST_CWD}:${GUEST_CWD}" # allowing the package to writing in its own directory
 
         # Passing node binary
-        - /usr/bin/node:/usr/bin/node:ro
-        # Apparently, node needs this file to start ($HOME=/ in the container)
-
-###
-# npm is run with $PWD = ./project-alpha in host
-# contained-run-script-sh is run with ./project-alpha:/home/node-app
-#     and $PWD = ./project-alpha/node_modules/worm
-# node infect.js is run inside the container with $PWD = /home/node-app
-# 
-# What would be needed is a way to forward the part of contained-run-script-sh::$PWD that is after the thing that matches /home/node-app, that is running node infect.js with $PWD = /home/node-app/node_modules/worm (= contained-run-script-sh::$PWD - what /home/node-app is mapped to (~/projects/containednpm/project-alpha))
-# Maybe `npm prefix can help`
+        - /usr/bin/node:/usr/bin/node:ro

readme.md

@@ -24,7 +24,7 @@ cd containednpm
 # (optional but recommanded) builds the image a first time and make sure it runs properly
 docker-compose -f contained-services.yml run contained_npm_script echo 'success'
 
-npm config set script-shell "$PWD"/bin/contained-run-script-sh
+npm config set script-shell "$PWD"/bin/contained-run-script-sh.js
 ````
 
 
@@ -48,7 +48,7 @@ cat package.json
 cd .. 
 git checkout project-alpha
 
-npm config set script-shell "$PWD"/bin/contained-run-script-sh
+npm config set script-shell "$PWD"/bin/contained-run-script-sh.js
 
 cd project-alpha
 ls -l node_modules