test: add test data for empty inputs

src/silo/preprocessing/preprocessor.test.cpp

@@ -113,6 +113,40 @@ const Scenario TSV_FILE_WITH_SQL_KEYWORD_AS_FIELD = {
    .expected_query_result = NDJSON_WITH_SQL_KEYWORD_AS_FIELD.expected_query_result
 };
 
+const Scenario EMPTY_INPUT_TSV = {
+   .input_directory = "testBaseData/exampleDatasetEmpty/",
+   .expected_sequence_count = 2,
+   .query = R"(
+      {
+         "action": {
+           "type": "Details"
+         },
+         "filterExpression": {
+            "type": "True"
+         }
+      }
+   )",
+   .expected_query_result = nlohmann::json::parse(R"(
+[])")
+};
+
+const Scenario EMPTY_INPUT_NDJSON = {
+   .input_directory = "testBaseData/exampleDatasetEmpty/",
+   .expected_sequence_count = 2,
+   .query = R"(
+      {
+         "action": {
+           "type": "Details"
+         },
+         "filterExpression": {
+            "type": "True"
+         }
+      }
+   )",
+   .expected_query_result = nlohmann::json::parse(R"(
+[])")
+};
+
 class PreprocessorTestFixture : public ::testing::TestWithParam<Scenario> {};
 
 INSTANTIATE_TEST_SUITE_P(
@@ -123,7 +157,9 @@ INSTANTIATE_TEST_SUITE_P(
       NDJSON_FILE_WITH_MISSING_SEGMENTS_AND_GENES,
       NDJSON_WITH_SQL_KEYWORD_AS_FIELD,
       TSV_FILE_WITH_SQL_KEYWORD_AS_FIELD,
-      NDJSON_WITH_NUMERIC_NAMES
+      NDJSON_WITH_NUMERIC_NAMES,
+      EMPTY_INPUT_TSV,
+      EMPTY_INPUT_NDJSON
    ),
    printTestName
 );

testBaseData/emptyInputNdjson/database_config.yaml

@@ -0,0 +1,31 @@
+schema:
+  instanceName: sars_cov-2_minimal_test_config
+  metadata:
+    - name: gisaid_epi_isl
+      type: string
+    - name: date
+      type: date
+    - name: unsorted_date
+      type: date
+    - name: region
+      type: string
+      generateIndex: true
+    - name: country
+      type: string
+      generateIndex: true
+    - name: pango_lineage
+      type: pango_lineage
+    - name: division
+      type: string
+      generateIndex: true
+    - name: age
+      type: int
+    - name: qc_value
+      type: float
+    - name: nucleotideInsertions
+      type: insertion
+    - name: aminoAcidInsertions
+      type: aaInsertion
+  primaryKey: gisaid_epi_isl
+  dateToSortBy: date
+  partitionBy: pango_lineage