Fix calculation of base package

Author: soumyaPrakashB

components/sbm-core/src/main/java/org/springframework/sbm/java/util/BasePackageCalculator.java

@@ -20,46 +20,52 @@
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Component;
 
+import java.util.List;
 import java.util.ArrayList;
 import java.util.Comparator;
-import java.util.List;
-import java.util.Optional;
 
+/**
+ * Calculates and returns the base package when given a list of JavaSource
+ *
+ * @author Soumya Prakash Behera
+ */
 @Component
 @RequiredArgsConstructor
 public class BasePackageCalculator {
 
     private final SbmApplicationProperties sbmApplicationProperties;
 
     public String calculateBasePackage(List<JavaSource> javaSources) {
-       if(javaSources.isEmpty()) return sbmApplicationProperties.getDefaultBasePackage();
+        if(javaSources.isEmpty()) {
+            return sbmApplicationProperties.getDefaultBasePackage();
+        }
+
+        if(javaSources.size() == 1) {
+           return javaSources.get(0).getPackageName();
+        }
+
+        List<String[]> javaSourcesAsStringArray = new ArrayList<>();
+
+        for(JavaSource javaSource : javaSources) {
+            javaSourcesAsStringArray.add(javaSource.getPackageName().split("\\."));
+        }
+
+        javaSourcesAsStringArray.sort(Comparator.comparingInt(str -> str.length));
 
-        List<JavaSource> sortableJavaSources = new ArrayList<>();
-        sortableJavaSources.addAll(javaSources);
-        javaSources = sortableJavaSources;
-        javaSources.sort(Comparator.comparing(js -> js.getPackageName().split("\\.").length));
-        JavaSource javaSourceInBasePackage = javaSources.get(0);
-        if(javaSources.size() > 1) {
-            JavaSource shortestPackage = javaSourceInBasePackage;
-            String shortestPackageName = shortestPackage.getPackageName();
+        String[] shortestPackage = javaSourcesAsStringArray.get(0);
 
-            Optional<JavaSource> javaSourceInDifferentBasePackage = javaSources.stream()
-                    .filter(js -> !js.getPackageName().startsWith(shortestPackageName))
-                    .findFirst();
+        StringBuilder sb = new StringBuilder();
 
-            if(javaSourceInDifferentBasePackage.isPresent()) {
-                return sbmApplicationProperties.getDefaultBasePackage();
-                /*
-                throw new RuntimeException(String.format("Could not calculate base package. Found at least two conflicting candidates: [%s] and [%s] found in these resources [%s] and [%s]",
-                        javaSources.get(0).getPackageName(),
-                        javaSourceInDifferentBasePackage.get().getPackageName(),
-                        javaSources.get(0).getAbsolutePath(),
-                        javaSourceInDifferentBasePackage.get().getAbsolutePath()));
-                 */
+        for(int i = 0; i < shortestPackage.length; i++) {
+            for (String[] strArray : javaSourcesAsStringArray) {
+                if(!strArray[i].equals(shortestPackage[i])) {
+                    return sb.isEmpty() ? "" : sb.substring(1);
+                }
             }
+            sb.append(".").append(shortestPackage[i]);
         }
 
-        return javaSourceInBasePackage.getPackageName();
+        return String.join(".", shortestPackage);
     }
 
 }

components/sbm-core/src/test/java/org/springframework/sbm/build/impl/JavaSourceSetImplTest.java

@@ -78,7 +78,7 @@ void getBasePackageShouldReturnDefaultIfNoDistinctRootPackageExists() {
                 .getMainJavaSourceSet();
 
         JavaSourceLocation location = sut.getJavaSourceLocation();
-        assertThat(location.getPackageName()).isEqualTo(sbmApplicationProperties.getDefaultBasePackage());
+        assertThat(location.getPackageName()).isEqualTo("org.springframework.sbm");
         assertThat(location.getSourceFolder()).isEqualTo(TestProjectContext.getDefaultProjectRoot().resolve("src/main/java"));
     }
 
@@ -104,7 +104,7 @@ void testGetBasePackageShouldConsiderLevelNotLength() {
                 .getMainJavaSourceSet();
 
         JavaSourceLocation location = sut.getJavaSourceLocation();
-        assertThat(location.getPackageName()).isEqualTo(sbmApplicationProperties.getDefaultBasePackage());
+        assertThat(location.getPackageName()).isEqualTo("org.springframework");
     }
 
     @Test

components/sbm-core/src/test/java/org/springframework/sbm/java/util/BasePackageCalculatorTest.java

@@ -62,7 +62,7 @@ void calculateBasePackageWithTwoAmbiguousPackages() {
 
         List<JavaSource> javaSources = getJavaSources(package1, package2, package3);
 
-        assertThat(sut.calculateBasePackage(javaSources)).isEqualTo(DEFAULT_PACKAGENAME);
+        assertThat(sut.calculateBasePackage(javaSources)).isEqualTo("");
     }
 
     @Test
@@ -83,10 +83,29 @@ void calculateBasePackageWithOneBasePackage2() {
         String package1 = "com.example.foo";
         String package2 = "com.example.foo";
         String package3 = "com.example.bar";
-
         List<JavaSource> javaSources = getJavaSources(package1, package2, package3);
 
-        assertThat(sut.calculateBasePackage(javaSources)).isEqualTo(DEFAULT_PACKAGENAME);
+        assertThat(sut.calculateBasePackage(javaSources)).isEqualTo("com.example");
+    }
+
+    @Test
+    void calculateBasePackageWithOneBasePackage3() {
+        String package1 = "com.acme.some.A.C";
+        String package2 = "com.acme.other.B";
+
+        List<JavaSource> javaSources = getJavaSources(package1, package2);
+
+        assertThat(sut.calculateBasePackage(javaSources)).isEqualTo("com.acme");
+    }
+
+    @Test
+    void calculateBasePackageWithSameBasePackages() {
+        String package1 = "com.acme.some.B";
+        String package2 = "com.acme.some.B";
+
+        List<JavaSource> javaSources = getJavaSources(package1, package2);
+
+        assertThat(sut.calculateBasePackage(javaSources)).isEqualTo("com.acme.some.B");
     }
 
     @Test
@@ -104,7 +123,7 @@ void calculateBasePackageWithAmbiguousBasePackage() {
         List<JavaSource> javaSources = getJavaSources(package1, package2, package3);
 
         Path curDir = Path.of(".").toAbsolutePath().normalize();
-        assertThat(sut.calculateBasePackage(javaSources)).isEqualTo(DEFAULT_PACKAGENAME);
+        assertThat(sut.calculateBasePackage(javaSources)).isEqualTo("com.example");
     }
 
     @NotNull