Fix for #18 - support running with --no-scripts flag

.travis.yml

@@ -9,6 +9,7 @@ env:
   - DEPENDENCIES=""
   - DEPENDENCIES="--prefer-lowest --prefer-stable"
   - DEPENDENCIES="--classmap-authoritative"
+  - DEPENDENCIES="--no-scripts"
 
 before_script:
   - sh .travis.install.sh

src/PackageVersions/FallbackVersions.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace PackageVersions;
+
+/**
+ * @internal
+ *
+ * This is a fallback for {@see \PackageVersions\Versions::getVersion()}
+ * Do not use this class directly: it is intended to be only used when
+ * {@see \PackageVersions\Versions} fails to be generated, which typically
+ * happens when running composer with `--no-scripts` flag)
+ */
+final class FallbackVersions
+{
+    private function __construct()
+    {
+    }
+
+    /**
+     * @param string $packageName
+     *
+     * @return string
+     *
+     * @throws \OutOfBoundsException if a version cannot be located
+     * @throws \UnexpectedValueException if the composer.lock file could not be located
+     */
+    public static function getVersion(string $packageName) : string
+    {
+        $versions = iterator_to_array(self::getVersions(self::getComposerLockPath()));
+
+        if (! array_key_exists($packageName, $versions)) {
+            throw new \OutOfBoundsException(
+                'Required package "' . $packageName . '" is not installed: cannot detect its version'
+            );
+        }
+
+        return $versions[$packageName];
+    }
+
+    /**
+     * @return string
+     *
+     * @throws \UnexpectedValueException
+     */
+    private static function getComposerLockPath() : string
+    {
+        // bold assumption, but there's not here to fix everyone's problems.
+        $checkedPaths = [__DIR__ . '/../../../../../composer.lock', __DIR__ . '/../../composer.lock'];
+
+        foreach ($checkedPaths as $path) {
+            if (file_exists($path)) {
+                return $path;
+            }
+        }
+
+        throw new \UnexpectedValueException(sprintf(
+            'PackageVersions could not locate your `composer.lock` location. This is assumed to be in %s. '
+            . 'If you customized your composer vendor directory and ran composer installation with --no-scripts, '
+            . 'then you are on your own, and we can\'t really help you. Fix your shit and cut the tooling some slack.',
+            json_encode($checkedPaths)
+        ));
+    }
+
+    private static function getVersions(string $composerLockFile) : \Generator
+    {
+        $lockData = json_decode(file_get_contents($composerLockFile), true);
+
+        $lockData['packages-dev'] = $lockData['packages-dev'] ?? [];
+
+        foreach (array_merge($lockData['packages'], $lockData['packages-dev']) as $package) {
+            yield $package['name'] => $package['version'] . '@' . (
+                $package['source']['reference']?? $package['dist']['reference'] ?? ''
+            );
+        }
+
+        yield 'unknown/root-package@UNKNOWN';
+    }
+}

src/PackageVersions/Versions.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace PackageVersions;
+
+/**
+ * This is a stub class: it is in place only for scenarios where PackageVersions
+ * is installed with a `--no-scripts` flag, in which scenarios the Versions class
+ * is not being replaced.
+ *
+ * If you are reading this docBlock inside your `vendor/` dir, then this means
+ * that PackageVersions didn't correctly install, and is in "fallback" mode.
+ */
+final class Versions
+{
+    const VERSIONS = [];
+
+    private function __construct()
+    {
+    }
+
+    /**
+     * @throws \OutOfBoundsException if a version cannot be located
+     * @throws \UnexpectedValueException if the composer.lock file could not be located
+     */
+    public static function getVersion(string $packageName) : string
+    {
+        return FallbackVersions::getVersion($packageName);
+    }
+}

test/PackageVersionsTest/FallbackVersionsTest.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace PackageVersionsTest;
+
+use PackageVersions\FallbackVersions;
+use PackageVersions\Versions;
+use PHPUnit_Framework_TestCase;
+
+/**
+ * @covers \PackageVersions\FallbackVersions
+ */
+final class FallbackVersionsTest extends PHPUnit_Framework_TestCase
+{
+    public function testWillFailWithoutValidComposerLockLocation()
+    {
+        rename(__DIR__ . '/../../composer.lock', __DIR__ . '/../../composer.lock.backup');
+
+        try {
+            FallbackVersions::getVersion('phpunit/phpunit');
+
+            self::fail('An exception was supposed to be thrown');
+        } catch (\UnexpectedValueException $lockFileNotFound) {
+            $srcDir = realpath(__DIR__ . '/../../src/PackageVersions');
+
+            self::assertSame(
+                'PackageVersions could not locate your `composer.lock` location. '
+                . 'This is assumed to be in '
+                . json_encode([$srcDir . '/../../../../../composer.lock', $srcDir . '/../../composer.lock'])
+                . '. If you customized your composer vendor directory and ran composer installation with --no-scripts, '
+                . 'then you are on your own, and we can\'t really help you. '
+                . 'Fix your shit and cut the tooling some slack.',
+                $lockFileNotFound->getMessage()
+            );
+        }
+
+        rename(__DIR__ . '/../../composer.lock.backup', __DIR__ . '/../../composer.lock');
+    }
+
+    public function testValidVersions()
+    {
+        $lockData = json_decode(file_get_contents(__DIR__ . '/../../composer.lock'), true);
+
+        $packages = array_merge($lockData['packages'], $lockData['packages-dev']);
+
+        self::assertNotEmpty($packages);
+
+        foreach ($packages as $package) {
+            self::assertSame(
+                $package['version'] . '@' . $package['source']['reference'],
+                Versions::getVersion($package['name'])
+            );
+        }
+    }
+
+    public function testInvalidVersionsAreRejected()
+    {
+        $this->expectException(\OutOfBoundsException::class);
+
+        Versions::getVersion(uniqid('', true) . '/' . uniqid('', true));
+    }
+}