Resolve dependencies when imports are relative to the package path

gazelle/python/file_parser.go

@@ -165,7 +165,9 @@ func (p *FileParser) parseImportStatements(node *sitter.Node) bool {
 		}
 	} else if node.Type() == sitterNodeTypeImportFromStatement {
 		from := node.Child(1).Content(p.code)
-		if strings.HasPrefix(from, ".") {
+		// If the import is from the current package, we don't need to add it to the modules i.e. from . import Class1.
+		// If the import is from a different relative package i.e. from .package1 import foo, we need to add it to the modules.
+		if from == "." {
 			return true
 		}
 		for j := 3; j < int(node.ChildCount()); j++ {

gazelle/python/resolve.go

@@ -148,12 +148,56 @@ func (py *Resolver) Resolve(
 		modules := modulesRaw.(*treeset.Set)
 		it := modules.Iterator()
 		explainDependency := os.Getenv("EXPLAIN_DEPENDENCY")
+		// Resolve relative paths for package generation
+		isPackageGeneration := !cfg.PerFileGeneration() && !cfg.CoarseGrainedGeneration()
 		hasFatalError := false
 	MODULES_LOOP:
 		for it.Next() {
 			mod := it.Value().(module)
-			moduleParts := strings.Split(mod.Name, ".")
-			possibleModules := []string{mod.Name}
+			moduleName := mod.Name
+			// Transform relative imports `.` or `..foo.bar` into the package path from root.
+			if strings.HasPrefix(moduleName, ".") {
+				// If not package generation mode, skip relative imports
+				if !isPackageGeneration {
+					continue MODULES_LOOP
+				}
+				relativeDepth := 0
+				for i := 0; i < len(moduleName); i++ {
+					if moduleName[i] == '.' {
+						relativeDepth++
+					} else {
+						break
+					}
+				}
+
+				// Extract suffix after leading dots
+				relativeSuffix := moduleName[relativeDepth:]
+				var relativeSuffixParts []string
+				if relativeSuffix != "" {
+					relativeSuffixParts = strings.Split(relativeSuffix, ".")
+				}
+
+				// Split current package label into parts
+				pkgParts := strings.Split(from.Pkg, "/")
+
+				if relativeDepth- 1 > len(pkgParts) {
+					// Trying to go above the root
+					log.Printf("ERROR: Invalid relative import %q in %q: exceeds package root.", moduleName, mod.Filepath)
+					continue MODULES_LOOP
+				}
+
+				// Go up `relativeDepth - 1` levels
+				baseParts := pkgParts
+				if relativeDepth > 1 {
+					baseParts = pkgParts[:len(pkgParts)-(relativeDepth-1)]
+				}
+
+				absParts := append(baseParts, relativeSuffixParts...)
+				moduleName = strings.Join(absParts, ".")
+			}
+
+			moduleParts := strings.Split(moduleName, ".")
+			possibleModules := []string{moduleName}
 			for len(moduleParts) > 1 {
 				// Iterate back through the possible imports until
 				// a match is found.

gazelle/python/testdata/relative_imports/BUILD.out

@@ -1,23 +1,14 @@
-load("@rules_python//python:defs.bzl", "py_binary", "py_library")
+load("@rules_python//python:defs.bzl", "py_binary")
 
 # gazelle:resolve py resolved_package //package2:resolved_package
 
-py_library(
-    name = "relative_imports",
-    srcs = [
-        "package1/module1.py",
-        "package1/module2.py",
-    ],
-    visibility = ["//:__subpackages__"],
-)
-
 py_binary(
     name = "relative_imports_bin",
     srcs = ["__main__.py"],
     main = "__main__.py",
     visibility = ["//:__subpackages__"],
     deps = [
-        ":relative_imports",
+        "//package1",
         "//package2",
     ],
 )

gazelle/python/testdata/relative_imports/package1/BUILD.out

@@ -0,0 +1,10 @@
+load("@rules_python//python:defs.bzl", "py_library")
+
+py_library(
+    name = "package1",
+    srcs = [
+        "module1.py",
+        "module2.py",
+    ],
+    visibility = ["//:__subpackages__"],
+)

gazelle/python/testdata/relative_imports/package2/BUILD.out

@@ -6,8 +6,10 @@ py_library(
         "__init__.py",
         "module3.py",
         "module4.py",
-        "subpackage1/module5.py",
     ],
     visibility = ["//:__subpackages__"],
-    deps = [":resolved_package"],
+    deps = [
+        ":resolved_package",
+        "//package2/subpackage1",
+    ],
 )

gazelle/python/testdata/relative_imports/package2/subpackage1/BUILD.out

@@ -0,0 +1,8 @@
+load("@rules_python//python:defs.bzl", "py_library")
+
+py_library(
+    name = "subpackage1",
+    srcs = ["module5.py"],
+    visibility = ["//:__subpackages__"],
+    deps = ["//package2"],
+)

gazelle/python/testdata/resolve_deps_relative_imports/BUILD.in

@@ -0,0 +1 @@
+# gazelle:python_generation_mode package

gazelle/python/testdata/resolve_deps_relative_imports/BUILD.out

@@ -0,0 +1,14 @@
+load("@rules_python//python:defs.bzl", "py_binary")
+
+# gazelle:python_generation_mode package
+
+py_binary(
+    name = "resolve_deps_relative_imports_bin",
+    srcs = ["__main__.py"],
+    main = "__main__.py",
+    visibility = ["//:__subpackages__"],
+    deps = [
+        "//package1",
+        "//package2",
+    ],
+)

gazelle/python/testdata/resolve_deps_relative_imports/README.md

@@ -0,0 +1,3 @@
+# Resolve deps for relative imports
+
+This test case verifies that the generated targets correctly handle relative imports in Python. Specifically, when the Python generation mode is set to "package," it ensures that relative import statements such as from .foo import X are properly resolved to their corresponding modules.

gazelle/python/testdata/resolve_deps_relative_imports/WORKSPACE

@@ -0,0 +1 @@
+# This is a test data Bazel workspace.

gazelle/python/testdata/resolve_deps_relative_imports/__main__.py

@@ -0,0 +1,5 @@
+from package1.module1 import function1
+from package2.module3 import function3
+
+print(function1())
+print(function3())

gazelle/python/testdata/resolve_deps_relative_imports/package1/BUILD.out

@@ -0,0 +1,10 @@
+load("@rules_python//python:defs.bzl", "py_library")
+
+py_library(
+    name = "package1",
+    srcs = [
+        "module1.py",
+        "module2.py",
+    ],
+    visibility = ["//:__subpackages__"],
+)

gazelle/python/testdata/resolve_deps_relative_imports/package1/module1.py

@@ -0,0 +1,19 @@
+# Copyright 2023 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from .module2 import function2
+
+
+def function1():
+    return "function1 " + function2()

gazelle/python/testdata/resolve_deps_relative_imports/package1/module2.py

@@ -0,0 +1,17 @@
+# Copyright 2023 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+def function2():
+    return "function2"

gazelle/python/testdata/resolve_deps_relative_imports/package2/BUILD.out

@@ -0,0 +1,12 @@
+load("@rules_python//python:defs.bzl", "py_library")
+
+py_library(
+    name = "package2",
+    srcs = [
+        "__init__.py",
+        "module3.py",
+        "module4.py",
+    ],
+    visibility = ["//:__subpackages__"],
+    deps = ["//package2/library"],
+)

gazelle/python/testdata/resolve_deps_relative_imports/package2/__init__.py

@@ -0,0 +1,20 @@
+from .library import add as _add
+from .library import divide as _divide
+from .library import multiply as _multiply
+from .library import subtract as _subtract
+
+
+def add(a, b):
+    return _add(a, b)
+
+
+def divide(a, b):
+    return _divide(a, b)
+
+
+def multiply(a, b):
+    return _multiply(a, b)
+
+
+def subtract(a, b):
+    return _subtract(a, b)

gazelle/python/testdata/resolve_deps_relative_imports/package2/library/BUILD.out

@@ -0,0 +1,7 @@
+load("@rules_python//python:defs.bzl", "py_library")
+
+py_library(
+    name = "library",
+    srcs = ["__init__.py"],
+    visibility = ["//:__subpackages__"],
+)

gazelle/python/testdata/resolve_deps_relative_imports/package2/library/__init__.py

@@ -0,0 +1,14 @@
+def add(a, b):
+    return a + b
+
+
+def divide(a, b):
+    return a / b
+
+
+def multiply(a, b):
+    return a * b
+
+
+def subtract(a, b):
+    return a - b

gazelle/python/testdata/resolve_deps_relative_imports/package2/module3.py

@@ -0,0 +1,5 @@
+from .library import function5
+
+
+def function3():
+    return "function3 " + function5()

gazelle/python/testdata/resolve_deps_relative_imports/package2/module4.py

@@ -0,0 +1,2 @@
+def function4():
+    return "function4"

gazelle/python/testdata/resolve_deps_relative_imports/test.yaml

@@ -0,0 +1,15 @@
+# Copyright 2023 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+---