SCANJLIB-223 Never send null or missing values to the scanner engine

Author: henryju

lib/src/main/java/org/sonarsource/scanner/lib/internal/ScannerEngineLauncher.java

@@ -27,6 +27,7 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.stream.Collectors;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -118,10 +119,12 @@ private static List<String> split(String value) {
 
   private static String buildJsonProperties(Map<String, String> properties) {
     JsonArray propertiesArray = new JsonArray();
-    properties.entrySet().stream().sorted(Map.Entry.comparingByKey()).forEach(prop -> {
+    properties.entrySet().stream()
+      .filter(prop -> prop.getKey() != null)
+      .sorted(Map.Entry.comparingByKey()).forEach(prop -> {
       JsonObject property = new JsonObject();
       property.addProperty("key", prop.getKey());
-      property.addProperty("value", prop.getValue());
+      property.addProperty("value", Optional.ofNullable(prop.getValue()).orElse(""));
       propertiesArray.add(property);
     });
     JsonObject jsonObject = new JsonObject();

lib/src/test/java/org/sonarsource/scanner/lib/internal/ScannerEngineLauncherTest.java

@@ -20,6 +20,7 @@
 package org.sonarsource.scanner.lib.internal;
 
 import java.nio.file.Path;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import org.junit.jupiter.api.Test;
@@ -63,6 +64,23 @@ void execute() {
       any());
   }
 
+  @Test
+  void replace_null_values_by_empty_in_json_and_ignore_null_key() {
+    var scannerEngine = temp.resolve("scanner-engine.jar");
+
+    ScannerEngineLauncher launcher = new ScannerEngineLauncher(javaRunner, new CachedFile(scannerEngine, true));
+
+    Map<String, String> properties = new HashMap<>();
+    properties.put("sonar.myProp", null);
+    properties.put(null, "someValue");
+    launcher.execute(properties);
+
+    verify(javaRunner).execute(
+      eq(List.of("-jar", scannerEngine.toAbsolutePath().toString())),
+      eq("{\"scannerProperties\":[{\"key\":\"sonar.myProp\",\"value\":\"\"}]}"),
+      any());
+  }
+
   @Test
   void tryParse_shouldParseLogMessages() {
     ScannerEngineLauncher.tryParse("{\n" +