test: add tests to ensure patient id pseudonym

This uses fake MTBFile JSON as described here:
https://ibmi-intra.cs.uni-tuebingen.de/display/ZPM/bwHC+REST+API

src/test/kotlin/dev/dnpm/etl/processor/pseudonym/ExtensionsTest.kt

@@ -0,0 +1,64 @@
+/*
+ * This file is part of ETL-Processor
+ *
+ * Copyright (c) 2023  Comprehensive Cancer Center Mainfranken, Datenintegrationszentrum Philipps-Universität Marburg and Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package dev.dnpm.etl.processor.pseudonym
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import de.ukw.ccc.bwhc.dto.MtbFile
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.extension.ExtendWith
+import org.mockito.ArgumentMatchers
+import org.mockito.Mock
+import org.mockito.junit.jupiter.MockitoExtension
+import org.mockito.kotlin.doAnswer
+import org.mockito.kotlin.whenever
+import org.springframework.core.io.ClassPathResource
+
+const val FAKE_MTB_FILE_PATH = "fake_MTBFile.json"
+const val CLEAN_PATIENT_ID = "5dad2f0b-49c6-47d8-a952-7b9e9e0f7549"
+
+@ExtendWith(MockitoExtension::class)
+class ExtensionsTest {
+
+    private fun fakeMtbFile(): MtbFile {
+        val mtbFile = ClassPathResource(FAKE_MTB_FILE_PATH).inputStream
+        return ObjectMapper().readValue(mtbFile, MtbFile::class.java)
+    }
+
+    private fun MtbFile.serialized(): String {
+        return ObjectMapper().writeValueAsString(this)
+    }
+
+    @Test
+    fun shouldNotContainCleanPatientId(@Mock pseudonymizeService: PseudonymizeService) {
+        doAnswer {
+            it.arguments[0]
+            "PSEUDO-ID"
+        }.whenever(pseudonymizeService).patientPseudonym(ArgumentMatchers.anyString())
+
+        val mtbFile = fakeMtbFile()
+
+        mtbFile.pseudonymizeWith(pseudonymizeService)
+
+        assertThat(mtbFile.patient.id).isEqualTo("PSEUDO-ID")
+        assertThat(mtbFile.serialized()).doesNotContain(CLEAN_PATIENT_ID)
+    }
+
+}