Improve aliases for Pydantic models

[blubber]

The pydantic models generated include field aliases for fields that use camel case as opposed to snake case (customary in Python). The alias definitions are compatible with python's builtin dataclasses and are correctly detected by LSPs, however in the same models the populate_by_name option is set to True. This option allows the instantiotion using the actual field names (snake case) instead of the defined alias (camcel case). This options is not correctly recognized by most LSP and therefore results in two warnings per field. The first warning states that hte snake case version of the field is not a valid argument, and the second warning states that the camcel case version of the argument is missing.

Exampel:

class WebSessionInfo(BaseModel):
    model_config = {
        "populate_by_name": True,
    }

    session_id: str = Field(alias="sessionID")

The above model can be instantiated like so:
WebSessionInfo(session_id='abc'), however this results in two warnings (session_id is not a valid argument, and sessionID is missing).

Settings validation_alias and serialization_alias results in the exact same behavior as far as validation and serialization are concerned, however they are not standard dataclass options and are therefore not recognized by LSPs. This removes the warnings.

PR checklist

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---

Summary by cubic

Switch generated Pydantic v1 fields to use validation_alias and serialization_alias instead of alias to prevent LSP warnings when populate_by_name=True. Validation and serialization behavior is unchanged; snake_case init and camelCase I/O still work.

• Bug Fixes
  • For fields where baseName != name, emit validation_alias and serialization_alias in Field() within AbstractPythonPydanticV1Codegen.

^{Written for commit ba30bdc. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 1 file

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them.


<file name="modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonPydanticV1Codegen.java">

<violation number="1" location="modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonPydanticV1Codegen.java:911">
P1: Pydantic v1 generator emits v2-only Field kwargs (`validation_alias`/`serialization_alias`), causing runtime TypeError and alias breakage.</violation>
</file>

---

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[cubic-dev-ai]

P1: Pydantic v1 generator emits v2-only Field kwargs (validation_alias/serialization_alias), causing runtime TypeError and alias breakage.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractPythonPydanticV1Codegen.java, line 911:

<comment>Pydantic v1 generator emits v2-only Field kwargs (`validation_alias`/`serialization_alias`), causing runtime TypeError and alias breakage.</comment>

<file context>
@@ -908,7 +908,8 @@ private ModelsMap postProcessModelsMap(ModelsMap objs) {
                 // field
                 if (cp.baseName != null && !cp.baseName.equals(cp.name)) { // base name not the same as name
-                    fields.add(String.format(Locale.ROOT, "alias=\"%s\"", cp.baseName));
+                    fields.add(String.format(Locale.ROOT, "validation_alias=\"%s\"", cp.baseName));
+                    fields.add(String.format(Locale.ROOT, "serialization_alias=\"%s\"", cp.baseName));
                 }
</file context>

Suggested change

	fields.add(String.format(Locale.ROOT, "validation_alias=\"%s\"", cp.baseName));
	fields.add(String.format(Locale.ROOT, "serialization_alias=\"%s\"", cp.baseName));
	fields.add(String.format(Locale.ROOT, "alias=\"%s\"", cp.baseName));

[wing328]

thanks for the pr

please follow step 3 to update the samples