[license] Handle missing license metadata (#227)

CHANGELOG.md

@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Rewrite drifted Git hooks by removing the previous target first, restore the intended `0o755` executable mode, and report unwritable hook replacements cleanly when `.git/hooks` stays locked (#190)
 - Keep Composer plugin command discovery compatible with consumer environments by moving unsupported Symfony Console named parameters out of command metadata/configuration and by decoupling the custom filesystem wrapper from Composer's bundled Symfony Filesystem signatures (#185)
 - Keep Composer autoload, Rector, and ECS from traversing nested fixture `vendor` directories when the composer-plugin consumer fixture has installed dependencies (#179)
+- Skip LICENSE generation cleanly when a consumer composer manifest omits or leaves the `license` field empty (#227)
 
 ## [1.20.0] - 2026-04-23
 

src/License/Resolver.php

@@ -47,14 +47,18 @@ final class Resolver implements ResolverInterface
     /**
      * Resolves a license identifier to its template filename.
      *
-     * @param string $license The license identifier to resolve
+     * @param string|null $license The license identifier to resolve
      *
      * @return string|null The template filename if supported, or null if not
      */
-    public function resolve(string $license): ?string
+    public function resolve(?string $license): ?string
     {
         $normalized = $this->normalize($license);
 
+        if (null === $normalized) {
+            return null;
+        }
+
         if (! isset(self::SUPPORTED_LICENSES[$normalized])) {
             return null;
         }
@@ -65,12 +69,18 @@ public function resolve(string $license): ?string
     /**
      * Normalizes the license identifier for comparison.
      *
-     * @param string $license The license identifier to normalize
+     * @param string|null $license The license identifier to normalize
      *
-     * @return string The normalized license string
+     * @return string|null The normalized license string, or null when unavailable
      */
-    private function normalize(string $license): string
+    private function normalize(?string $license): ?string
     {
-        return trim($license);
+        if (null === $license) {
+            return null;
+        }
+
+        $license = trim($license);
+
+        return '' === $license ? null : $license;
     }
 }

src/License/ResolverInterface.php

@@ -30,9 +30,9 @@ interface ResolverInterface
     /**
      * Resolves a license identifier to its template filename.
      *
-     * @param string $license The license identifier to resolve
+     * @param string|null $license The license identifier to resolve
      *
      * @return string|null The template filename if supported, or null if not
      */
-    public function resolve(string $license): ?string;
+    public function resolve(?string $license): ?string;
 }

tests/License/GeneratorTest.php

@@ -109,6 +109,24 @@ public function generateWithUnsupportedLicenseWillReturnNull(): void
         self::assertNull($result);
     }
 
+    /**
+     * @return void
+     */
+    #[Test]
+    public function generateWithMissingLicenseWillReturnNull(): void
+    {
+        $this->composer->getLicense()
+            ->willReturn(null);
+        $this->resolver->resolve(null)
+            ->willReturn(null);
+        $this->filesystem->dumpFile(Argument::cetera())
+            ->shouldNotBeCalled();
+
+        $result = $this->generator->generate('/tmp/LICENSE');
+
+        self::assertNull($result);
+    }
+
     /**
      * @return void
      */

tests/License/ResolverTest.php

@@ -65,4 +65,22 @@ public function resolveWithUnknownLicenseWillReturnNull(): void
     {
         self::assertNull($this->resolver->resolve('Unknown-License'));
     }
+
+    /**
+     * @return void
+     */
+    #[Test]
+    public function resolveWithMissingLicenseWillReturnNull(): void
+    {
+        self::assertNull($this->resolver->resolve(null));
+    }
+
+    /**
+     * @return void
+     */
+    #[Test]
+    public function resolveWithEmptyLicenseWillReturnNull(): void
+    {
+        self::assertNull($this->resolver->resolve('  '));
+    }
 }