SONARPY-3837 Reorder package root resolution and add src as default package when poetry backend is used (#889)

GitOrigin-RevId: c88192e0365cf2d16653419f7d9aa45a3a8a7997

Author: joke1196

python-commons/src/main/java/org/sonar/plugins/python/indexer/PackageRootResolver.java

@@ -70,16 +70,16 @@ public static List<String> resolve(List<String> extractedRoots, Configuration co
    * @return list of fallback package root absolute paths
    */
   static List<String> resolveFallback(Configuration config, File baseDir) {
-    String[] sonarSources = config.getStringArray(SONAR_SOURCES_KEY);
-    if (sonarSources.length > 0) {
-      return toAbsolutePaths(Arrays.asList(sonarSources), baseDir);
-    }
-
     List<String> conventionalFolders = findConventionalFolders(baseDir);
     if (!conventionalFolders.isEmpty()) {
       return toAbsolutePaths(conventionalFolders, baseDir);
     }
 
+    String[] sonarSources = config.getStringArray(SONAR_SOURCES_KEY);
+    if (sonarSources.length > 0) {
+      return toAbsolutePaths(Arrays.asList(sonarSources), baseDir);
+    }
+
     return List.of(baseDir.getAbsolutePath());
   }
 

python-commons/src/main/java/org/sonar/plugins/python/indexer/PyProjectTomlSourceRoots.java

@@ -39,7 +39,8 @@
  * <p>Supports the following build systems:
  * <ul>
  *   <li>setuptools: {@code [tool.setuptools.packages.find] where = ["src"]}</li>
- *   <li>Poetry: {@code [tool.poetry] packages = [{from = "src", include = "pkg"}]}</li>
+ *   <li>Poetry: {@code [tool.poetry] packages = [{from = "src", include = "pkg"}]}
+ *       or auto-detects src/ layout when build-backend is poetry.core.masonry.api</li>
  *   <li>Hatchling: {@code [tool.hatch.build.targets.wheel] sources = ["src"]}</li>
  *   <li>uv_build: {@code [build-system] build-backend = "uv_build"} or {@code [tool.uv.build-backend] module-root = "src"} - auto-detects src/ layout by convention</li>
  *   <li>PDM: {@code [tool.pdm] package-dir = "src"}</li>
@@ -130,7 +131,7 @@ private static PyProjectExtractionResult extractFromConfig(PyProjectConfig confi
         detectedBuildSystems.add(PackageResolutionResult.BuildSystem.SETUPTOOLS);
       }
 
-      List<String> poetryRoots = extractFromPoetry(configTool.poetry());
+      List<String> poetryRoots = extractFromPoetry(configTool.poetry(), config.buildSystem());
       if (!poetryRoots.isEmpty()) {
         sourceRoots.addAll(poetryRoots);
         detectedBuildSystems.add(PackageResolutionResult.BuildSystem.POETRY);
@@ -199,6 +200,16 @@ private static List<String> extractFromUVBuildSystem(@Nullable BuildSystem build
     return List.of();
   }
 
+  /**
+   * Checks if the build backend is Poetry (e.g., poetry.core.masonry.api).
+   */
+  private static boolean isPoetryBuildBackend(@Nullable BuildSystem buildSystem) {
+    if (buildSystem == null || buildSystem.buildBackend() == null) {
+      return false;
+    }
+    return buildSystem.buildBackend().contains("poetry");
+  }
+
   // === Setuptools ===
   // [tool.setuptools.packages.find]
   // where = ["src"]
@@ -213,16 +224,30 @@ private static List<String> extractFromSetuptools(@Nullable Setuptools setuptool
   // === Poetry ===
   // [tool.poetry]
   // packages = [{ include = "mypackage", from = "src" }]
+  // Or auto-detects src/ layout when build-backend is poetry.core.masonry.api
+
+  private static List<String> extractFromPoetry(@Nullable Poetry poetry, @Nullable BuildSystem buildSystem) {
+    // First try to get explicit "from" paths from packages
+    if (poetry != null) {
+      List<String> explicitRoots = poetry.packages().stream()
+        .map(PoetryPackage::from)
+        .filter(from -> from != null && !from.isEmpty())
+        .distinct()
+        .toList();
 
-  private static List<String> extractFromPoetry(@Nullable Poetry poetry) {
-    if (poetry == null) {
-      return List.of();
+      if (!explicitRoots.isEmpty()) {
+        return explicitRoots;
+      }
     }
-    return poetry.packages().stream()
-      .map(PoetryPackage::from)
-      .filter(from -> from != null && !from.isEmpty())
-      .distinct()
-      .toList();
+
+    // If Poetry is the build backend but no explicit paths, use src-layout default
+    // Poetry auto-detects packages in src/ or project root; we default to src/
+    // and rely on legacy fallback for flat-layout projects
+    if (isPoetryBuildBackend(buildSystem)) {
+      return List.of("src");
+    }
+
+    return List.of();
   }
 
   // === Hatchling ===

python-commons/src/test/java/org/sonar/plugins/python/indexer/PyProjectTomlSourceRootsTest.java

@@ -193,6 +193,66 @@ void extract_poetry_onlyDependencies() {
       """)).isEmpty();
   }
 
+  // === Poetry Auto-Detection ===
+
+  @Test
+  void extract_poetry_autoDetect_withBuildBackend_returnsSrc() {
+    assertThat(extract("""
+      [build-system]
+      build-backend = "poetry.core.masonry.api"
+      requires = ["poetry-core"]
+
+      [tool.poetry]
+      name = "mypackage"
+      version = "0.1.0"
+      """)).containsExactly("src");
+  }
+
+  @Test
+  void extract_poetry_autoDetect_emptyPackages_returnsSrc() {
+    assertThat(extract("""
+      [build-system]
+      build-backend = "poetry.core.masonry.api"
+      requires = ["poetry-core"]
+
+      [tool.poetry]
+      packages = []
+      """)).containsExactly("src");
+  }
+
+  @Test
+  void extract_poetry_autoDetect_packagesWithoutFrom_returnsSrc() {
+    assertThat(extract("""
+      [build-system]
+      build-backend = "poetry.core.masonry.api"
+      requires = ["poetry-core"]
+
+      [tool.poetry]
+      packages = [{ include = "mypackage" }]
+      """)).containsExactly("src");
+  }
+
+  @Test
+  void extract_poetry_explicitFrom_overridesAutoDetect() {
+    assertThat(extract("""
+      [build-system]
+      build-backend = "poetry.core.masonry.api"
+      requires = ["poetry-core"]
+
+      [tool.poetry]
+      packages = [{ include = "mypackage", from = "lib" }]
+      """)).containsExactly("lib");
+  }
+
+  @Test
+  void extract_poetry_noBuildBackend_noPackages_returnsEmpty() {
+    assertThat(extract("""
+      [tool.poetry]
+      name = "mypackage"
+      version = "0.1.0"
+      """)).isEmpty();
+  }
+
   // === Hatchling ===
 
   @Test
@@ -550,6 +610,22 @@ void extractWithBuildSystem_poetry_detectsBuildSystem() {
     assertThat(result.buildSystem()).isEqualTo(PackageResolutionResult.BuildSystem.POETRY);
   }
 
+  @Test
+  void extractWithBuildSystem_poetry_autoDetect_detectsBuildSystem() {
+    var result = extractWithBuildSystem("""
+      [build-system]
+      build-backend = "poetry.core.masonry.api"
+      requires = ["poetry-core"]
+
+      [tool.poetry]
+      name = "mypackage"
+      version = "0.1.0"
+      """);
+
+    assertThat(result.relativeRoots()).containsExactly("src");
+    assertThat(result.buildSystem()).isEqualTo(PackageResolutionResult.BuildSystem.POETRY);
+  }
+
   @Test
   void extractWithBuildSystem_hatchling_detectsBuildSystem() {
     var result = extractWithBuildSystem("""