test(scanner): Add a test for serializing FileList

Since f38b42d the `FileListResolverTest` does not implicitly test the
serialization of file lists anymore, so add a separate test case for
that.

Signed-off-by: Martin Nonnenmacher <martin.nonnenmacher@bosch.com>

scanner/src/test/kotlin/FileListTest.kt

@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2024 The ORT Project Authors (see <https://github.com/oss-review-toolkit/ort/blob/main/NOTICE>)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * License-Filename: LICENSE
+ */
+
+package org.ossreviewtoolkit.scanner
+
+import io.kotest.core.spec.style.WordSpec
+import io.kotest.matchers.shouldBe
+
+import org.ossreviewtoolkit.model.toYaml
+
+class FileListTest : WordSpec({
+    "serializing a file list" should {
+        "sort the files" {
+            val fileList = FileList(
+                files = setOf(
+                    FileList.FileEntry("src/test.kt", "sha1"),
+                    FileList.FileEntry("src/main.kt", "sha1"),
+                    FileList.FileEntry("README.md", "sha1")
+                ),
+                ignorePatterns = emptySet()
+            )
+
+            fileList.toYaml().trim() shouldBe """
+                ---
+                ignore_patterns: []
+                files:
+                - path: "README.md"
+                  sha1: "sha1"
+                - path: "src/main.kt"
+                  sha1: "sha1"
+                - path: "src/test.kt"
+                  sha1: "sha1"
+            """.trimIndent()
+        }
+
+        "sort the ignore patterns" {
+            val fileList = FileList(
+                files = emptySet(),
+                ignorePatterns = setOf(
+                    "src/test/**",
+                    "src/funTest/**",
+                    "README.md"
+                )
+            )
+
+            fileList.toYaml().trim() shouldBe """
+                ---
+                ignore_patterns:
+                - "README.md"
+                - "src/funTest/**"
+                - "src/test/**"
+                files: []
+            """.trimIndent()
+        }
+    }
+})