[python] Add DPG TypedDict generation opt-out by Copilot · Pull Request #11372 · microsoft/typespec

Copilot · 2026-07-23T15:48:52Z

DPG mode in the Python emitter always generated TypedDict request-body overloads, with no tspconfig escape hatch. This adds an explicit emitter option so callers can keep models-mode: dpg while disabling automatic TypedDict generation.

New emitter option
- Adds generate-typeddict to @typespec/http-client-python
- Defaults to true to preserve current behavior
- Can be set in tspconfig.yaml to opt out of DPG TypedDict auto-generation
Generator behavior
- Updates Python generator options to recognize generate-typeddict
- In DPG mode, skips creating TypedDict body overload copies when the option is false
- Leaves the existing DPG model/binary overload behavior unchanged
Tests
- Adds focused coverage for the new option default
- Adds regression coverage that generate-typeddict: false suppresses TypedDict copy generation in DPG mode
Docs
- Documents the new option in the package README and generated emitter reference

Example:

options:
  "@typespec/http-client-python":
    models-mode: dpg
    generate-typeddict: false

Fixes [python] tspconfig to disable typeddict auto-generation #11354

azure-pipelines · 2026-07-23T15:49:23Z

Azure Pipelines: Successfully started running 1 pipeline(s). 1 pipeline(s) were filtered out due to trigger conditions. There may be pipelines that require an authorized user to comment /azp run to run.

Co-authored-by: l0lawrence <100643745+l0lawrence@users.noreply.github.com>

l0lawrence · 2026-07-23T19:22:40Z

@copilot if we dont generate the typeddict overload we should generate the JSON overload

Co-authored-by: l0lawrence <100643745+l0lawrence@users.noreply.github.com>

Copilot · 2026-07-23T19:27:13Z

@copilot if we dont generate the typeddict overload we should generate the JSON overload

Addressed in 3f8f519. I added regression coverage that generate-typeddict: false keeps the flattened JSON spread-body overload (alongside the binary overload) without emitting a TypedDict copy.

pkg-pr-new · 2026-07-23T21:48:13Z

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npm i https://pkg.pr.new/@typespec/http-client-python@11372

commit: 025eceb

github-actions · 2026-07-23T21:50:28Z

All changed packages have been documented.

✅ @typespec/http-client-python

Show changes

`@typespec/http-client-python` - feature ✏️

Add a generate-typeddict emitter option to opt out of generating TypedDict request-body overloads in models-mode: dpg. Defaults to true; set it to false to disable the DPG TypedDict overloads.

github-actions · 2026-07-23T22:01:20Z

Python emitter diff

Baseline gh:42feb121b9cc8edbd7a2aee2367c3c3d17f9bf33 vs this PR.

No changes to generated output.

Rendered diff: inline on the run summary, or the emitter-diff-html artifact.

Informational check (eng/emitter-diff); does not block the PR.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 753f3788-98a9-4e39-8655-9c6a3ce90536

@overload

…alse When generate-typeddict: false, the opt-out now performs a true revert to pre-TypedDict behavior by restoring the standalone raw-JSON dict @overload (and JSON in the impl Union) for both the explicit/model body path and the spread path, instead of only dropping the TypedDict overload. - add_overloads_for_body_param: only skip the single-body JSON overload when a TypedDict overload was actually inserted; otherwise keep it. - add_body_param_type: insert the raw-JSON (any-object) overload via new _insert_json_overload helper when TypedDict generation is disabled. - Update test_typeddict_overloads.py opt-out tests to assert the restored [model, JSON, binary] / flattened+JSON+binary overload sets. Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 753f3788-98a9-4e39-8655-9c6a3ce90536

Copilot

Pull request overview

This PR adds a new @typespec/http-client-python emitter option (generate-typeddict) to let users opt out of generating TypedDict request-body overloads while keeping models-mode: dpg, preserving default behavior (true) for back-compat.

Changes:

Added generate-typeddict option surfaced via the emitter’s TypeScript options schema and the Python generator’s OptionsDict defaults.
Updated the Python preprocess plugin to conditionally insert TypedDict vs raw-JSON overload types based on generate-typeddict.
Added unit tests and updated docs/reference material to cover and describe the new option.

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
website/src/content/docs/docs/emitters/clients/http-client-python/reference/emitter.md	Documents the new `generate-typeddict` option in the website emitter reference.
packages/http-client-python/tests/unit/test_typeddict_overloads.py	Adds regression tests for disabling TypedDict overload generation in DPG mode.
packages/http-client-python/tests/unit/test_options_dict.py	Adds unit coverage for the option defaulting to `true` and being settable to `false`.
packages/http-client-python/README.md	Documents the new `generate-typeddict` option in the package README.
packages/http-client-python/generator/pygen/preprocess/init.py	Implements the opt-out behavior and adjusts overload generation logic.
packages/http-client-python/generator/pygen/init.py	Adds the option default (`generate-typeddict: True`) to `OptionsDict`.
packages/http-client-python/emitter/src/lib.ts	Adds the option to the TypeScript emitter options interface and JSON schema.
.chronus/changes/python-disable-typeddict-generation-2026-7-24-12-59-0.md	Adds a Chronus changelog entry for the new feature.

+            # When a TypedDict overload was inserted, it replaces the single-body JSON
+            # overload, so skip it. When TypedDict generation is disabled, no TypedDict
+            # overload exists and we keep the single-body raw-JSON overload (pre-TypedDict
+            # behavior) by falling through.
+            if any(t.get("base") == "typeddict" for t in body_parameter["type"]["types"]):
+                continue


+def test_spread_body_opt_out_keeps_json_overload():
+    """Spread bodies revert to pre-TypedDict: flattened + single-body JSON + binary."""
+    plugin = _plugin("dpg", **{"generate-typeddict": False})
+    spread_body = _json_spread_body_parameter("CreateRequest", "Contoso.Widget")
+    yaml_data = {
+        "name": "create",
+        "bodyParameter": spread_body,
+        "parameters": [_content_type_param()],
+        "overloads": [],
+        "responses": [],
+        "exceptions": [],
+    }
+    code_model = {"types": [spread_body["type"]]}
+
+    plugin.add_body_param_type(code_model, spread_body)
+    add_overloads_for_body_param(yaml_data)
+
+    assert spread_body["type"]["type"] == "combined"
+    assert spread_body["type"]["types"][0]["base"] == "json"
+    assert spread_body["type"]["types"][1] == {"type": "binary"}
+    assert len(yaml_data["overloads"]) == 3
+    json_overloads = [o for o in yaml_data["overloads"] if o["bodyParameter"]["type"].get("base") == "json"]
+    # Both a flattened (keyword params) overload AND a single-body raw-JSON overload.
+    assert any(o["bodyParameter"].get("flattened") for o in json_overloads)
+    assert any(not o["bodyParameter"].get("flattened") for o in json_overloads)
+    assert not any(t for t in code_model["types"] if t.get("base") == "typeddict")


Initial plan

b9e1f80

Copilot AI assigned Copilot and l0lawrence Jul 23, 2026

Copilot started work on behalf of l0lawrence July 23, 2026 15:50 View session

Copilot AI linked an issue Jul 23, 2026 that may be closed by this pull request

[python] tspconfig to disable typeddict auto-generation #11354

Open

feat(http-client-python): add dpg typeddict opt-out

fb6b9cb

Co-authored-by: l0lawrence <100643745+l0lawrence@users.noreply.github.com>

microsoft-github-policy-service Bot added meta:website TypeSpec.io updates emitter:client:python Issue for the Python client emitter: @typespec/http-client-python labels Jul 23, 2026

Copilot AI changed the title ~~[WIP] Add option to disable typeddict auto-generation in dpg mode~~ [python] Add DPG TypedDict generation opt-out Jul 23, 2026

Copilot finished work on behalf of l0lawrence July 23, 2026 15:57

Copilot AI requested a review from l0lawrence July 23, 2026 15:57

Copilot started work on behalf of l0lawrence July 23, 2026 19:23 View session

test(http-client-python): cover json overload when typeddict is disabled

3f8f519

Co-authored-by: l0lawrence <100643745+l0lawrence@users.noreply.github.com>

Copilot finished work on behalf of l0lawrence July 23, 2026 19:27

Merge branch 'main' into copilot/python-disable-typeddict-generation

5014b3e

l0lawrence and others added 3 commits July 24, 2026 12:37

Merge branch 'main' into copilot/python-disable-typeddict-generation

c7a11a1

Add changeset for http-client-python TypedDict opt-out

be122e6

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com> Copilot-Session: 753f3788-98a9-4e39-8655-9c6a3ce90536

l0lawrence requested a review from Copilot July 27, 2026 17:54

Copilot started reviewing on behalf of l0lawrence July 27, 2026 17:55 View session

Copilot AI reviewed Jul 27, 2026

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[python] Add DPG TypedDict generation opt-out#11372
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