fix(core): adjust getFlatteningSourcePath to take into account multip…

…le parts path with naming conventions

packages/core/src/lib/utils/get-flattening-source-paths.util.ts

@@ -6,30 +6,49 @@ export function getFlatteningSourcePaths(
   namingConventions: [NamingConvention, NamingConvention]
 ) {
   const [sourceNamingConvention] = namingConventions;
-  const [first, ...paths] = srcPath
+  const splitSourcePaths = srcPath
     .split(sourceNamingConvention.splittingExpression)
     .filter(Boolean)
     .filter((p) => p !== '.');
 
-  if (!paths.length || !src.hasOwnProperty(first)) {
+  const lengthWithoutFirstPart = splitSourcePaths.length - 1;
+
+  if (!lengthWithoutFirstPart) {
+    return;
+  }
+
+  const [first, ...paths] = splitSourcePaths.slice(0, lengthWithoutFirstPart);
+  let trueFirstPartOfSource = first;
+  let stopIndex = 0;
+  let found = false;
+
+  if (src.hasOwnProperty(trueFirstPartOfSource)) {
+    found = true;
+  } else {
+    for (let i = 0, len = paths.length; i < len; i++) {
+      trueFirstPartOfSource = sourceNamingConvention.transformPropertyName([
+        trueFirstPartOfSource,
+        paths[i],
+      ]);
+      if (src.hasOwnProperty(trueFirstPartOfSource)) {
+        stopIndex = i + 1;
+        found = true;
+        break;
+      }
+    }
+  }
+
+  if (!found) {
     return;
   }
 
-  const sourcePaths = [
-    [first]
+  return [
+    [trueFirstPartOfSource]
       .concat(
-        paths.map((p) => sourceNamingConvention.transformPropertyName([p]))
+        sourceNamingConvention.transformPropertyName(
+          splitSourcePaths.slice(stopIndex + 1, splitSourcePaths.length + 1)
+        )
       )
       .join('.'),
   ];
-
-  if (paths.length > 1) {
-    sourcePaths.push(
-      [first]
-        .concat(sourceNamingConvention.transformPropertyName(paths))
-        .join('.')
-    );
-  }
-
-  return sourcePaths;
 }