[fix] handle empty map in each kind of import

Author: FrogDevelopper

consul-populate-core/src/main/java/com/frogdevelopment/consul/populate/files/JsonFilesImporter.java

@@ -7,6 +7,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.SequencedMap;
+
 import jakarta.inject.Singleton;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
@@ -61,6 +62,9 @@ protected SequencedMap<String, Object> readFile(@NonNull final File file) throws
     @NonNull
     @Override
     protected String writeValueAsString(@NonNull final Map<String, Object> map) throws JsonProcessingException {
+        if (map == null || map.isEmpty()) {
+            return "";
+        }
         return objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(map);
     }
 }

consul-populate-core/src/main/java/com/frogdevelopment/consul/populate/files/PropertiesFilesImporter.java

@@ -9,6 +9,7 @@
 import java.util.Properties;
 import java.util.SequencedMap;
 import java.util.stream.Collectors;
+
 import jakarta.inject.Singleton;
 
 import io.micronaut.context.annotation.Requires;
@@ -57,6 +58,9 @@ protected SequencedMap<String, Object> readFile(@NonNull final File file) throws
     @NonNull
     @Override
     protected String writeValueAsString(@NonNull final Map<String, Object> map) {
+        if (map == null || map.isEmpty()) {
+            return "";
+        }
         return map.entrySet()
                 .stream()
                 .map(entry -> entry.getKey() + "=" + entry.getValue())

consul-populate-core/src/main/java/com/frogdevelopment/consul/populate/files/YamlFilesImporter.java

@@ -6,6 +6,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.SequencedMap;
+
 import jakarta.inject.Singleton;
 
 import org.yaml.snakeyaml.Yaml;
@@ -54,6 +55,9 @@ protected SequencedMap<String, Object> readFile(@NonNull final File file) throws
     @NonNull
     @Override
     protected String writeValueAsString(@NonNull final Map<String, Object> map) {
+        if (map == null || map.isEmpty()) {
+            return "";
+        }
         return yaml.dumpAsMap(map);
     }
 }

consul-populate-core/src/test/java/com/frogdevelopment/consul/populate/files/JsonFilesImporterTest.java

@@ -2,13 +2,17 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+import java.util.TreeMap;
+
 import jakarta.inject.Inject;
 
 import org.intellij.lang.annotations.Language;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.CsvSource;
 
+import com.fasterxml.jackson.core.JsonProcessingException;
+
 import io.micronaut.context.annotation.Property;
 
 @Property(name = "consul.files.format", value = "JSON")
@@ -76,4 +80,14 @@ void should_mergeJson() {
                 .hasSize(1)
                 .containsEntry("application", EXPECTED);
     }
+
+    @Test
+    void should_handle_empty() throws JsonProcessingException {
+        // given
+        // when
+        final var value = filesImporter.writeValueAsString(new TreeMap<>());
+
+        // then
+        assertThat(value).isBlank();
+    }
 }

consul-populate-core/src/test/java/com/frogdevelopment/consul/populate/files/PropertiesFilesImporterTest.java

@@ -2,6 +2,8 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+import java.util.TreeMap;
+
 import jakarta.inject.Inject;
 
 import org.intellij.lang.annotations.Language;
@@ -53,4 +55,14 @@ void should_mergeProperties() {
                 .containsEntry("application", EXPECTED);
     }
 
+    @Test
+    void should_handle_empty() {
+        // given
+        // when
+        final var value = filesImporter.writeValueAsString(new TreeMap<>());
+
+        // then
+        assertThat(value).isBlank();
+    }
+
 }

consul-populate-core/src/test/java/com/frogdevelopment/consul/populate/files/YamlFilesImporterTest.java

@@ -2,6 +2,8 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+import java.util.TreeMap;
+
 import jakarta.inject.Inject;
 
 import org.intellij.lang.annotations.Language;
@@ -70,4 +72,14 @@ void should_mergeYaml() {
                 .hasSize(1)
                 .containsEntry("application", EXPECTED);
     }
+
+    @Test
+    void should_handle_empty() {
+        // given
+        // when
+        final var value = filesImporter.writeValueAsString(new TreeMap<>());
+
+        // then
+        assertThat(value).isBlank();
+    }
 }