phpcodesniffer-composer-installer issue #24

"Few things are harder to put up with than the annoyance of a good example." ~ Mark Twain

Example to accompany issue #24 of phpcodesniffer-composer-installer.

Introduction

On github, jrfnl asked how phpcodesniffer-composer-installer handles installing multiple standards.

This repository is an example implementation to show how this works.

It is supposed to function fully standalone, no external dependencies are required.

Just add PHP.

The result of the accompanying tests can be seen online at this projects Travis-CI page.

Tests are present for both "local" (project-specific) and "global" (system-wide) scenario's.

Original question

The following questions were posed:

Question

Say you have a project in which you require both a project specific coding standard, such as the Joomla or WordPress Coding Standards, as well as the PHPCompatibility standard to check for cross-version compatibility issues.

Assume that both these PHPCS standards require this library and have their type set to phpcodesniffer-standard,

How does this installer handle that ?

PHPCS by default overwrites a previously registered installed_path when the command is run again.

Does this library collect all the paths and run the command once at the end ? Or would each subsequent CS dependency overwrite the path like PHPCS does ?

Related: squizlabs/PHP_CodeSniffer#1436

and

What about if the user installs the sniff library as "global" using Composer and they already have one or more other standards installed globally ? (which they're not updating at the same time)

Expected behaviour

Given the scenario that a user has defined two sniffs as a dependency, the expected behaviour would be that the installer installs both sniffs.

This should lead to the path of both sniffs being present in the PHP Codesniffer configuration file at vendor/squizlabs/php_codesniffer/CodeSniffer.conf.

Whether the sniffs are installed one-by-one or altogether, and whether the sniffs are installed locally or globally also should not make a difference for the end result.

There is a slightly different scenario when a sniff is already installed before the installer is installed.

In such a case, the installer does not do anything (as the sniff is already installed and no installation is needed).

However, when another sniff is installed, both sniffs will be installed by the installer.

Steps to reproduce

1. Install the installer and two sniffs as composer dependency.
2. Validate the CLI output of composer
3. Validate the contents of vendor/squizlabs/php_codesniffer/CodeSniffer.conf
4. Repeat test incrementally
5. Repeat incremental test with sniff installed before installer

1. Install the installer and sniffs

The following command should be run to require the installer and two separate sniffs:

php composer.phar require --sort-packages 'dealerdirect/phpcodesniffer-composer-installer' 'frenck/php-compatibility' 'drupal/coder'

2. Validate CLI output

This should give output similar to the following:

Please note the following line in the output:

PHP CodeSniffer Config installed_paths set to
  /path/to/phpcodesniffer-composer-installer_issue-24/vendor/drupal/coder/coder_sniffer,
  /path/to/phpcodesniffer-composer-installer_issue-24/vendor/frenck/php-compatibility

This indicates that the path to both sniffs should be set in the CodeSniffer.conf file.

3. Validate CodeSniffer.conf

To make sure this is correct, the content of vendor/squizlabs/php_codesniffer/CodeSniffer.conf needs to be examined.

It should contain something similar to the following:

<?php
 $phpCodeSnifferConfig = array (
  'installed_paths' => '/path/to/phpcodesniffer-composer-installer_issue-24/vendor/drupal/coder/coder_sniffer,/path/to/phpcodesniffer-composer-installer_issue-24/vendor/frenck/php-compatibility',
)
?>

4. Repeat test incrementally

The result of the previous checks should not be different, whether or not all of the sniffs are installed together or apart.

To verify this, the packages are iterated over and the previous tests are called individually for each package.

The results should be the same and the re-used tests should all pass.

5. Repeat incremental test with sniff installed before installer

What happens if a sniff is already installed and the installer is installed afterwards?

If a new sniff is installed, will the "previous" sniff also be installed?

In order to validate this, the order in which the packages are installed is changed.

Instead of installing the installer first and the sniffs after that, first a sniff is installed, then the installer, then another sniff.

Re-using the previous test (which in turn re-uses the other tests) it can be validated that both sniffs are present after the last sniff is installed.

Proof

This repository provides tests that automatically runs through the steps described above. The test also contains assertions to validate the described behaviour.

Tests are present for both "local" (project-specific) and "global" (system-wide) scenario's.

Various versions of PHPUnit are shipped with this repository. This enables users to run the test against the PHP version of their choice:

PHP Version	PHPUnit Version
PHP 5.3 – 5.6	PHPUnit 4.8
PHP 5.6, 7.0/7.1.	PHPUnit 5.7
PHP 7.0/7.1.	PHPUnit 6.1

For example, to run the test for PHP 5.6, one of the following commands should be used:

php phpunit-4.8.35.phar

or

php phpunit-5.7.19.phar

This will run the test to validate the documented behaviour.

The result of these tests can be seen online at this projects Travis-CI page