Composer Not Generating Autoloads For Library - php

Question

I've set up two projects, an 'init' and a library, which is required by the init. They both have PSR-0 autoloads set, but the autoload values from the library are not added to the vendor/composer/autoload_namespaces.php in the init project.
Sample composer.json from the Library:
{
"name": "lxp/library",
"description": "A test library",
"autoload": {
"psr-0": {
"LXP\\Library": "src/"
}
}
}
Sample composer.json from the project that requires that library:
{
"name": "lxp/init",
"name": "A test init",
"autoload": {
"psr-0": {
"LXP\\Init": "src/"
}
},
"repositories": [
{
"type": "composer",
"url": "http://satis.repo.redacted/"
}
],
"require": {
"lxp/library": "dev-master"
}
}
The library contains the class LXP\Library\Something in the file src/LXP/Library/Something.php.
The project that requires the library contains the class LXP\Init\Now in the file src/LXP/Init/Now.php.
When running composer install in the 'init' project, it downloads the library project and puts it in vendor correctly, but vendor/composer/autoload_namespaces.php doesn't contain the library's autoload information, only that of the current project.
What am I doing wrong? If I run dump-autoload in the library project then the autoload_namespaces.php file is correct, and a quick bootstrap script confirms that it does indeed pick up the class.
EDIT - This is a problem with the satis-generated packages.json. To fix it, I had to add the autoload information from the library's composer.json into the json file I supply to satis, which seems like an unnecessary duplication and so I'm probably doing it wrong. Is there a single place that autoload information can be stored for satis libraries? For example, can satis read the composer.json files that exist in the libraries it scans?
EDIT #2 - Satis does not read the composer.jsons from repositories specified as 'package' type. This is obvious in hindsight, because 'package' is used for libraries that do not have a composer.json, and is a way to wrap composer-like dependency management around them.
Changing the satis.json's repository to 'vcs' type meant that the composer.json was read, and the information (including the autoload specification) was parsed and stored in the packages.json.
#Seldaek - thank you for suggesting that my satis config was the problem, and I hope that this clarifies satis / composer behaviour for anyone else in my position.

Answer 1

I see two possible mistakes you may have done that would cause this:
You forgot to update your satis repo so the autoload config for lxp/init is not up to date in there
You are running composer install from a lock file, and that means composer just reads the info from the composer.lock file and does not update package metadata to the latest version available in satis. To solve this you should run composer update instead.

Answer 2

Try composer dump-autoload command.

Answer 3

It depends how you installing your library via Composer. For example, when downloading it as package type (same I believe with composer type), Composer never reads the composer.json file, so instead you should use vcs or git type. See: GH-6846.
Here is composer.json which should work:
{
"require": {
"lxp/library": "dev-master"
},
"repositories": [
{
"type": "vcs",
"url": "http://satis.repo.redacted/"
}
]
}
Then run: composer install.
For troubleshooting, try running:
composer dump-autoload -o -vvv.
composer diagnose -vvv