* Have Composer in tools/composer and managed through composer self-update

* Install Psalm using Phive as `tools/psalm`
* Install PHP-CS-Fixer using Phive as `tools/php-cs-fixer`

Author: sebastianbergmann

.gitattributes

@@ -0,0 +1,4 @@
+/tools      export-ignore
+/tools/*    binary
+
+*.php diff=php

.travis.yml

@@ -9,7 +9,7 @@ php:
   - 7.4
 
 install:
-  - travis_retry composer update --no-interaction --no-ansi --no-progress --no-suggest --optimize-autoloader --prefer-stable
+  - travis_retry ./tools/composer update --no-interaction --no-ansi --no-progress --no-suggest
 
 script:
   - ./vendor/bin/phpunit --coverage-clover=coverage.xml

build.xml

@@ -1,21 +1,30 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project name="diff" default="setup">
-    <target name="setup" depends="clean,composer"/>
+    <target name="setup" depends="clean,install-dependencies"/>
 
     <target name="clean" description="Cleanup build artifacts">
         <delete dir="${basedir}/vendor"/>
         <delete file="${basedir}/composer.lock"/>
     </target>
 
-    <target name="composer" depends="clean" description="Install dependencies with Composer">
-        <exec executable="composer" taskname="composer">
+    <target name="install-dependencies" depends="clean" description="Install dependencies with Composer">
+        <exec executable="${basedir}/tools/composer" taskname="composer">
             <arg value="update"/>
             <arg value="--no-interaction"/>
             <arg value="--no-progress"/>
             <arg value="--no-ansi"/>
             <arg value="--no-suggest"/>
-            <arg value="--optimize-autoloader"/>
-            <arg value="--prefer-stable"/>
+        </exec>
+    </target>
+
+    <target name="update-tools">
+        <exec executable="phive" taskname="phive">
+            <arg value="--no-progress"/>
+            <arg value="update"/>
+        </exec>
+
+        <exec executable="${basedir}/tools/composer" taskname="composer">
+            <arg value="self-update"/>
         </exec>
     </target>
 </project>

composer.json

@@ -14,6 +14,11 @@
             "email": "[email protected]"
         }
     ],
+    "prefer-stable": true,
+    "config": {
+        "optimize-autoloader": true,
+        "sort-packages": true
+    },
     "require": {
         "php": "^7.1"
     },

phive.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phive xmlns="https://phar.io/phive">
+  <phar name="php-cs-fixer" version="^2.16" installed="2.16.1" ___location="./tools/php-cs-fixer" copy="true"/>
+  <phar name="psalm" version="^3.8" installed="3.8.3" ___location="./tools/psalm" copy="true"/>
+</phive>