Externalize installation of codeception/codeception and weirdan/codeception-psalm-module

These packages are runtimes that invoke `psalm/plugin-phpunit` via `exec()`, without sharing codespace with
it, and therefore are safe to externalize elsewhere.

We can't afford keeping these dependencies co-located with the main `composer.json` / `composer.lock`, as
they conflict with non-dev dependencies that we want to explicitly test against.

Author: Ocramius

.github/workflows/ci.yml

@@ -135,20 +135,38 @@ jobs:
               env:
                   COMPOSER_ROOT_VERSION: dev-master
 
+            - name: Install composer tool dependencies (high deps)
+              run: cd tools/codeception && composer update --prefer-dist --no-interaction
+              if: ${{matrix.deps == 'high'}}
+              env:
+                  COMPOSER_ROOT_VERSION: dev-master
+
             - name: Install composer dependencies (low deps)
               run: composer update --prefer-dist --no-interaction --prefer-stable --prefer-lowest
               if: ${{matrix.deps == 'low'}}
               env:
                   COMPOSER_ROOT_VERSION: dev-master
 
+            - name: Install composer tool dependencies (low deps)
+              run: cd tools/codeception && composer update --prefer-dist --no-interaction --prefer-stable --prefer-lowest
+              if: ${{matrix.deps == 'low'}}
+              env:
+                  COMPOSER_ROOT_VERSION: dev-master
+
             - name: Install composer dependencies (stable deps)
               run: composer update --prefer-dist --no-interaction --prefer-stable
               if: ${{matrix.deps == 'stable'}}
               env:
                   COMPOSER_ROOT_VERSION: dev-master
 
+            - name: Install composer tool dependencies (stable deps)
+              run: cd tools/codeception && composer update --prefer-dist --no-interaction --prefer-stable
+              if: ${{matrix.deps == 'stable'}}
+              env:
+                  COMPOSER_ROOT_VERSION: dev-master
+
             - name: Show Psalm version
               run: vendor/bin/psalm --version
 
             - name: Run tests
-              run: vendor/bin/codecept run -v
+              run: tools/codeception/vendor/bin/codecept run -v

composer.json

@@ -22,10 +22,8 @@
     },
     "require-dev": {
         "php": "^7.3 || ^8.0",
-        "codeception/codeception": "^4.0.3",
         "phpunit/phpunit": "^10.0 || ^11.0 || ^12.0",
         "squizlabs/php_codesniffer": "^3.3.1",
-        "weirdan/codeception-psalm-module": "^0.11.0",
         "weirdan/prophecy-shim": "^1.0 || ^2.0"
     },
     "extra": {

tools/codeception/composer.json

@@ -0,0 +1,16 @@
+{
+  "description": "Psalm plugin for PHPUnit - tools/codeception locked dependencies - used to run tests only!",
+  "require": {
+    "php": "~8.1.0 || ~8.2.0 || ~8.3.0 || ~8.4.0",
+    "codeception/codeception": "^4.0.3",
+    "weirdan/codeception-psalm-module": "^0.11.0"
+  },
+  "scripts": {
+    "test": "codecept run -v"
+  },
+  "config": {
+    "platform": {
+      "php": "8.1.99"
+    }
+  }
+}