ci: Use poe tasks for model generation in CI workflow (#705)

## Summary

- Add `generate-models-from-file` poe task that accepts a local file
path, working around `datamodel-codegen` ignoring `--input` when `url`
is set in `pyproject.toml`
- Update CI workflow to call poe tasks instead of `datamodel-codegen`
directly, ensuring the downloaded artifact from apify-docs PRs is
actually used

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: vdusek

.github/workflows/manual_regenerate_models.yaml

@@ -79,9 +79,9 @@ jobs:
       - name: Generate models from OpenAPI spec
         run: |
           if [[ -f openapi-spec/openapi.json ]]; then
-            uv run datamodel-codegen --input openapi-spec/openapi.json
+            uv run poe generate-models-from-file openapi-spec/openapi.json
           else
-            uv run datamodel-codegen
+            uv run poe generate-models
           fi
 
       - name: Commit model changes

pyproject.toml

@@ -208,7 +208,6 @@ context = 7
 
 # https://koxudaxi.github.io/datamodel-code-generator/
 [tool.datamodel-codegen]
-url = "https://docs.apify.com/api/openapi.json"
 input_file_type = "openapi"
 output = "src/apify_client/_models.py"
 target_python_version = "3.11"
@@ -269,4 +268,8 @@ shell = "./build_api_reference.sh && corepack enable && yarn && uv run yarn star
 cwd = "website"
 
 [tool.poe.tasks.generate-models]
-shell = "uv run datamodel-codegen"
+shell = "uv run datamodel-codegen --url https://docs.apify.com/api/openapi.json && python scripts/postprocess_generated_models.py"
+
+[tool.poe.tasks.generate-models-from-file]
+shell = "uv run datamodel-codegen --input $input_file && python scripts/postprocess_generated_models.py"
+args = [{ name = "input-file", positional = true, required = true }]

scripts/postprocess_generated_models.py

@@ -0,0 +1,46 @@
+"""Post-process the generated _models.py to fix known datamodel-codegen issues.
+
+Currently fixes:
+- Discriminator field names: datamodel-codegen sometimes emits the JSON property name (camelCase)
+  instead of the Python field name (snake_case) in `Field(discriminator='...')` annotations,
+  particularly when the discriminator is on a schema referenced inside array items.
+"""
+
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+MODELS_PATH = Path(__file__).resolve().parent.parent / 'src' / 'apify_client' / '_models.py'
+
+# Map of camelCase discriminator values to their snake_case equivalents.
+# Add new entries here as needed when the OpenAPI spec introduces new discriminators.
+DISCRIMINATOR_FIXES: dict[str, str] = {
+    'pricingModel': 'pricing_model',
+}
+
+
+def fix_discriminators(content: str) -> str:
+    """Replace camelCase discriminator values with their snake_case equivalents."""
+    for camel, snake in DISCRIMINATOR_FIXES.items():
+        content = re.sub(
+            rf"discriminator='{camel}'",
+            f"discriminator='{snake}'",
+            content,
+        )
+    return content
+
+
+def main() -> None:
+    content = MODELS_PATH.read_text()
+    fixed = fix_discriminators(content)
+
+    if fixed != content:
+        MODELS_PATH.write_text(fixed)
+        print(f'Fixed discriminator values in {MODELS_PATH}')
+    else:
+        print('No discriminator fixes needed')
+
+
+if __name__ == '__main__':
+    main()