Fix incorrect relative imports with --use-exact-imports and --collapse-root-models (#3020)

Author: koxudaxi

src/datamodel_code_generator/parser/base.py

@@ -1413,7 +1413,7 @@ def __change_from_import(  # noqa: PLR0913, PLR0914
                 else:
                     from_, import_ = full_path = relative(current_module_name, target_full_name)
                     if imports.use_exact:
-                        from_, import_ = exact_import(from_, import_, data_type.reference.short_name)
+                        from_, import_ = full_path = exact_import(from_, import_, data_type.reference.short_name)
                     import_ = import_.replace("-", "_")
                     current_module_path = tuple(current_module_name.split(".")) if current_module_name else ()
                     if (  # pragma: no cover

tests/data/expected/main/jsonschema/exact_imports_collapse_root_models_title/__init__.py

@@ -0,0 +1,2 @@
+# generated by datamodel-codegen:
+#   filename:  exact_imports_collapse_root_models_title

tests/data/expected/main/jsonschema/exact_imports_collapse_root_models_title/data/ReflectionSetData.py

@@ -0,0 +1,15 @@
+# generated by datamodel-codegen:
+#   filename:  data/ReflectionSetData.json
+
+from __future__ import annotations
+
+from pydantic import BaseModel, Field
+
+from ..datatypes.FooStats import FooStats
+
+
+class ReflectionSetData(BaseModel):
+    foo_stats_overall: FooStats | None = Field(None, alias='fooStatsOverall')
+    foo_stats_shells: list[FooStats] | None = Field(
+        None, alias='fooStatsShells', title='Foo Stats Shells'
+    )

tests/data/expected/main/jsonschema/exact_imports_collapse_root_models_title/data/__init__.py

@@ -0,0 +1,2 @@
+# generated by datamodel-codegen:
+#   filename:  exact_imports_collapse_root_models_title

tests/data/expected/main/jsonschema/exact_imports_collapse_root_models_title/datatypes/FooStats.py

@@ -0,0 +1,10 @@
+# generated by datamodel-codegen:
+#   filename:  datatypes/FooStats.json
+
+from __future__ import annotations
+
+from pydantic import BaseModel
+
+
+class FooStats(BaseModel):
+    pass

tests/data/expected/main/jsonschema/exact_imports_collapse_root_models_title/datatypes/__init__.py

@@ -0,0 +1,2 @@
+# generated by datamodel-codegen:
+#   filename:  exact_imports_collapse_root_models_title

tests/data/jsonschema/exact_imports_collapse_root_models_title/data/ReflectionSetData.json

@@ -0,0 +1,21 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "title": "ReflectionSetData",
+    "type": "object",
+    "properties": {
+        "fooStatsOverall": {
+            "allOf": [
+                {
+                    "$ref": "../datatypes/FooStats.json"
+                }
+            ]
+        },
+        "fooStatsShells": {
+            "items": {
+                "$ref": "../datatypes/FooStats.json"
+            },
+            "title": "Foo Stats Shells",
+            "type": "array"
+        }
+    }
+}

tests/data/jsonschema/exact_imports_collapse_root_models_title/datatypes/FooStats.json

@@ -0,0 +1,5 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "title": "FooStats",
+    "type": "object"
+}

tests/main/jsonschema/test_main_jsonschema.py

@@ -8729,3 +8729,32 @@ def test_main_exact_imports_collapse_root_models_module_class_collision(output_d
         ],
         force_exec_validation=True,
     )
+
+
+@PYDANTIC_V2_SKIP
+def test_main_exact_imports_collapse_root_models_title_array(output_dir: Path) -> None:
+    """Test --use-exact-imports with --collapse-root-models when array field has title.
+
+    Regression test for https://github.com/koxudaxi/datamodel-code-generator/issues/3001
+    When an allOf $ref and an array items $ref point to the same type, and the array
+    field has a title (causing a root model to be created and collapsed), both fields
+    should use the same import alias.
+    """
+    run_main_and_assert(
+        input_path=JSON_SCHEMA_DATA_PATH / "exact_imports_collapse_root_models_title",
+        output_path=output_dir,
+        input_file_type="jsonschema",
+        expected_directory=EXPECTED_JSON_SCHEMA_PATH / "exact_imports_collapse_root_models_title",
+        extra_args=[
+            "--output-model-type",
+            "pydantic_v2.BaseModel",
+            "--target-python-version",
+            "3.10",
+            "--use-exact-imports",
+            "--collapse-root-models",
+            "--use-title-as-name",
+            "--snake-case-field",
+            "--disable-timestamp",
+        ],
+        force_exec_validation=True,
+    )