diff --git a/test/unit/SelfManage/BuildTools/BinaryBuildToolFinderTest.php b/test/unit/SelfManage/BuildTools/BinaryBuildToolFinderTest.php
new file mode 100644
index 0000000..ac7c27d
--- /dev/null
+++ b/test/unit/SelfManage/BuildTools/BinaryBuildToolFinderTest.php
@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Php\PieUnitTest\SelfManage\BuildTools;
+
+use Php\Pie\Platform\TargetPhp\PhpBinaryPath;
+use Php\Pie\Platform\TargetPlatform;
+use Php\Pie\SelfManage\BuildTools\BinaryBuildToolFinder;
+use Php\Pie\SelfManage\BuildTools\PackageManager;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\TestCase;
+
+#[CoversClass(BinaryBuildToolFinder::class)]
+final class BinaryBuildToolFinderTest extends TestCase
+{
+    public function testCheckFailsToFindTool(): void
+    {
+        self::assertFalse((new BinaryBuildToolFinder('this-should-not-be-anything-in-path', []))->check());
+    }
+
+    public function testCheckFindsTool(): void
+    {
+        self::assertTrue((new BinaryBuildToolFinder('echo', []))->check());
+    }
+
+    public function testPackageNameIsNullWhenNoPackageConfiguredForPackageManager(): void
+    {
+        self::assertNull(
+            (new BinaryBuildToolFinder('a', []))
+                ->packageNameFor(
+                    PackageManager::Test,
+                    TargetPlatform::fromPhpBinaryPath(PhpBinaryPath::fromCurrentProcess(), null),
+                ),
+        );
+    }
+
+    public function testPackageNameIsNullWhenPackageConfiguredForPackageManagerIsNull(): void
+    {
+        self::assertNull(
+            (new BinaryBuildToolFinder('a', [PackageManager::Test->value => null]))
+                ->packageNameFor(
+                    PackageManager::Test,
+                    TargetPlatform::fromPhpBinaryPath(PhpBinaryPath::fromCurrentProcess(), null),
+                ),
+        );
+    }
+
+    public function testPackageNameIsReturnedWhenPackageConfiguredForPackageManager(): void
+    {
+        self::assertSame(
+            'the-package',
+            (new BinaryBuildToolFinder('a', [PackageManager::Test->value => 'the-package']))
+                ->packageNameFor(
+                    PackageManager::Test,
+                    TargetPlatform::fromPhpBinaryPath(PhpBinaryPath::fromCurrentProcess(), null),
+                ),
+        );
+    }
+
+    public function testPackageNameIsReturnedWithFormattingWhenPackageConfiguredForPackageManager(): void
+    {
+        $phpBinary = PhpBinaryPath::fromCurrentProcess();
+
+        self::assertSame(
+            'php' . $phpBinary->majorVersion() . $phpBinary->minorVersion() . '-dev',
+            (new BinaryBuildToolFinder('a', [PackageManager::Test->value => 'php{major}{minor}-dev']))
+                ->packageNameFor(
+                    PackageManager::Test,
+                    TargetPlatform::fromPhpBinaryPath($phpBinary, null),
+                ),
+        );
+    }
+}
diff --git a/test/unit/SelfManage/BuildTools/PackageManagerTest.php b/test/unit/SelfManage/BuildTools/PackageManagerTest.php
new file mode 100644
index 0000000..53a4092
--- /dev/null
+++ b/test/unit/SelfManage/BuildTools/PackageManagerTest.php
@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Php\PieUnitTest\SelfManage\BuildTools;
+
+use Php\Pie\SelfManage\BuildTools\PackageManager;
+use PHPUnit\Framework\Attributes\CoversClass;
+use PHPUnit\Framework\TestCase;
+
+#[CoversClass(PackageManager::class)]
+final class PackageManagerTest extends TestCase
+{
+    public function testInstallCommand(): void
+    {
+        self::assertSame(
+            ['echo', '"fake installing a, b"'],
+            PackageManager::Test->installCommand(['a', 'b']),
+        );
+        self::assertSame(
+            ['apt-get', 'install', '-y', '--no-install-recommends', '--no-install-suggests', 'a', 'b'],
+            PackageManager::Apt->installCommand(['a', 'b']),
+        );
+        self::assertSame(
+            ['apk', 'add', '--no-cache', 'a', 'b'],
+            PackageManager::Apk->installCommand(['a', 'b']),
+        );
+    }
+}