Multi-app projects using yarn in Ionic CI

Start with the root and project-specific ionic.config.js files shown in the report, then trace the Appflow dependency_install step that selects npm ci. Compare how the configuration is read for single-app and multi-app projects. Done means the multi-app configuration reliably selects the intended package manager and the dependency installation no longer falls back to npm.

Description:
I have a project which uses yarn instead of npm. The project could be successfully built in Ionic CI. I converted it to multi-app by adding another ionic.config.js-file. After that, I have not been able to build it, even with trying various different options.

The details on using yarn could be found in the documentation and they are verifiably correct. I got yarn to work in the CI with a single application project. I converted the application to monorepo (using yarn workspaces). I ran into build problems with Ionic CI. The details about using yarn with multi-app are not available or are misleading.

The CI prints the error as follows (timestamps removed):

Checking if cordova or capacitor project
Cordova project detected
--------------------------------
--- Step: dependency_install ---
--------------------------------
Installing Dependencies
$ npm ci --quiet --no-optional
▸ npm ERR! The `npm ci` command can only install with an existing package-lock.json or
▸ npm ERR! npm-shrinkwrap.json with lockfileVersion >= 1. Run an install with npm@5 or
▸ npm ERR! later to generate a package-lock.json file, then try again.
▸ npm ERR! A complete log of this run can be found in:
▸ npm ERR!     /root/.npm/_logs/2022-04-12T14_05_38_411Z-debug.log
`npm ci` failed falling back to `npm install`

I had the same issue when building a single package project. I fixed the error earlier by adding "yarn": true to the ionic.config.js.

After going multi-app, the yarn setting is not picked up. I tried the folllowing:

• add "yarn": true to the root of ./ionic.config.js
• add "npmClient": "yarn" to the root of ./ionic.config.js
• add "yarn": true to a project inside projects in ./ionic.config.js
• add "npmClient": "yarn" to a project inside projects in ./ionic.config.js
• add "yarn": true to the root of project-specific ./ws/app/ionic.config.js
• add "npmClient": "yarn" to the root of project-specific ./ws/app/ionic.config.js

Steps to Reproduce:

./ionic.config.js:

  "defaultProject": "app",
  "projects": {
    "app": {
      "name": "Mobile app",
      "integrations": {
        "capacitor": {}
      },
      "type": "react",
      "yarn": true,
      "root": "ws/app",
      "npmClient": "yarn"
    }
  },
  "yarn": true,
  "npmClient": "yarn"
}

./ws/app/ionic.config.js:

{
  "name": "app",
  "integrations": {
    "capacitor": {}
  },
  "type": "react",
  "yarn": true,
  "npmClient": "yarn"
}

Output:

Checking if cordova or capacitor project
Cordova project detected
--------------------------------
--- Step: dependency_install ---
--------------------------------
Installing Dependencies
$ npm ci --quiet --no-optional
▸ npm ERR! The `npm ci` command can only install with an existing package-lock.json or
▸ npm ERR! npm-shrinkwrap.json with lockfileVersion >= 1. Run an install with npm@5 or
▸ npm ERR! later to generate a package-lock.json file, then try again.
▸ npm ERR! A complete log of this run can be found in:
▸ npm ERR!     /root/.npm/_logs/2022-04-12T14_05_38_411Z-debug.log
`npm ci` failed falling back to `npm install`

My ionic info:

Ionic:

   Ionic CLI       : 5.4.16 (/Users/name/workspace/name/maind/dev/maind/node_modules/ionic)
   Ionic Framework : @ionic/react 6.0.13

Capacitor:

   Capacitor CLI   : 3.4.1
   @capacitor/core : 3.4.1

Utility:

   cordova-res : not installed
   native-run  : 1.5.0

System:

   NodeJS : v16.14.2 (/Users/name/.nvm/versions/node/v16.14.2/bin/node)
   npm    : 8.5.0
   OS     : macOS Big Sur

Other Information:

I would like to use Appflow to build and distribute the app to shops.