feat: add generic --feature-flag CLI arg and --list-feature-flags registry

[Kosinkadink]

Summary

Adds two new CLI arguments for runtime feature-flag control:

• --feature-flag KEY=VALUE (repeatable) — sets a server feature flag at startup. Values are auto-coerced to the registered type (bool / int / float); unregistered keys keep the raw string. Bare --feature-flag KEY (no =) defaults to the value true, so registered bool flags work as toggles.
• --list-feature-flags — prints the JSON registry of known CLI-settable flags and exits, so launchers (e.g. Desktop 2.0) can discover the valid flag set for a given ComfyUI version.

CLI-provided flags are merged into SERVER_FEATURE_FLAGS but cannot overwrite core flags (supports_preview_metadata, max_upload_size, extension, node_replacements, assets).

The registry currently exposes:

key	type	default	description
show_signin_button	bool	false	Show the sign-in button in the frontend even when not signed in

Example

python main.py --feature-flag show_signin_button=true
python main.py --feature-flag show_signin_button     # bare form, equivalent to =true
python main.py --list-feature-flags

Robustness

• Malformed values for typed flags (e.g. --feature-flag some_int=not_a_number) log a warning and fall back to the raw string instead of crashing startup.
• Empty keys are skipped.

Tests

tests-unit/feature_flags_test.py covers:

• Bool true/false coercion (case-insensitive)
• Unregistered keys remain strings
• Coercion-failure fallback (no startup crash)
• Single-flag parsing
• Bare-flag default-to-true
• Empty-key skipped
• Registry entries have all required fields (type, default, description)

All 17 tests pass.

---

Part of Comfy-Org/ComfyUI-Desktop-2.0-Beta#415.

[coderabbitai]

📝 Walkthrough

Walkthrough

Adds two CLI options: --feature-flag (repeatable; accepts KEY=VALUE or bare KEY) and --list-feature-flags (prints the CLI registry as JSON and exits). Introduces FeatureFlagInfo (TypedDict) and CLI_FEATURE_FLAG_REGISTRY with typed entries and defaults. Adds coercion helpers (_coerce_flag_value, _coerce_bool), a parser (_parse_cli_feature_flags) that treats bare keys as "true" and drops invalid/coercion-failing values, and logic to merge non-core CLI-provided flags into SERVER_FEATURE_FLAGS without overwriting core flags. Unit tests added for coercion, parsing, and registry shape.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 60.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the main change: adding a generic --feature-flag CLI argument and --list-feature-flags registry capability.
Description check	✅ Passed	The description is directly related to the changeset, providing clear context about the new CLI arguments and their functionality.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@comfy/cli_args.py`:
- Line 241: Update the CLI argument declaration for --feature-flag to document
that a bare key (no "=VALUE") is accepted and treated as true: change the
metavar from "KEY=VALUE" to something that shows both forms (e.g. "KEY[=VALUE]"
or "KEY|KEY=VALUE") and revise the help string in the call to
parser.add_argument("--feature-flag", ...) to explicitly mention that supplying
just KEY will set the flag to true, in addition to the existing examples about
boolean and numeric auto-conversion; keep the action='append' and default
behavior unchanged so the parsing code handling bare keys (implicit true)
matches the new help.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: a7b7d7c0-18ac-4424-9161-216b14fa30ca

📥 Commits

Reviewing files that changed from the base of the PR and between d187c35 and 0992141.

📒 Files selected for processing (1)

• comfy/cli_args.py

[rattus128]

One small UX comment

[coderabbitai]

🧹 Nitpick comments (2)

tests-unit/feature_flags_test.py (2)

132-141: ⚡ Quick win

Add coverage for registered-unknown-type fallback behavior.

_coerce_flag_value() intentionally returns raw string when a registered key has an unrecognized type. A small test here would prevent accidental behavior changes if registry types evolve.

Proposed test addition

 class TestCoerceFlagValue:
@@
     def test_failed_int_coercion_raises(self, monkeypatch):
@@
         with pytest.raises(ValueError):
             _coerce_flag_value("test_int_flag", "not_a_number")
+
+    def test_registered_unknown_type_stays_string(self, monkeypatch):
+        monkeypatch.setitem(
+            CLI_FEATURE_FLAG_REGISTRY,
+            "test_unknown_type",
+            {"type": "custom", "default": "", "description": "test"},
+        )
+        assert _coerce_flag_value("test_unknown_type", "abc") == "abc"

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@tests-unit/feature_flags_test.py` around lines 132 - 141, Add a unit test to
cover the registered-unknown-type fallback in _coerce_flag_value: use
monkeypatch.setitem to register a flag key (e.g., "test_unknown_type") in
CLI_FEATURE_FLAG_REGISTRY with a type value that _coerce_flag_value does not
recognize (e.g., "weird"), then call _coerce_flag_value("test_unknown_type",
"some_string") and assert it returns the raw string "some_string" unchanged;
place this alongside the existing tests (same file) to prevent regressions when
registry types change.

---

157-160: ⚡ Quick win

Add a whitespace-normalization parse test.

_parse_cli_feature_flags() strips both key and value, but current coverage only checks =value empty-key shape. Please add a case like " show_signin_button = true " and " =value" to lock in the trimming behavior.

Proposed test addition

 class TestParseCliFeatureFlags:
@@
     def test_empty_key_skipped(self, monkeypatch):
         monkeypatch.setattr("comfy_api.feature_flags.args", type("Args", (), {"feature_flag": ["=value", "valid=1"]})())
         result = _parse_cli_feature_flags()
         assert result == {"valid": "1"}
+
+    def test_whitespace_trimmed_and_blank_key_skipped(self, monkeypatch):
+        monkeypatch.setattr(
+            "comfy_api.feature_flags.args",
+            type("Args", (), {"feature_flag": ["  show_signin_button = true  ", "   =value"]})(),
+        )
+        result = _parse_cli_feature_flags()
+        assert result == {"show_signin_button": True}

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@tests-unit/feature_flags_test.py` around lines 157 - 160, Update the unit
test for CLI feature flag parsing by adding cases that exercise whitespace
normalization: in tests-unit/feature_flags_test.py modify or add to
test_empty_key_skipped so monkeypatch sets
comfy_api.feature_flags.args.feature_flag to include strings like " 
show_signin_button = true  " and "   =value" (in addition to the existing
"=value" and "valid=1"), then call _parse_cli_feature_flags() and assert the
result contains {"show_signin_button":"true","valid":"1"} while empty-key
entries are skipped; reference the _parse_cli_feature_flags function and the
test_empty_key_skipped test to locate where to change the input and expected
output.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@tests-unit/feature_flags_test.py`:
- Around line 132-141: Add a unit test to cover the registered-unknown-type
fallback in _coerce_flag_value: use monkeypatch.setitem to register a flag key
(e.g., "test_unknown_type") in CLI_FEATURE_FLAG_REGISTRY with a type value that
_coerce_flag_value does not recognize (e.g., "weird"), then call
_coerce_flag_value("test_unknown_type", "some_string") and assert it returns the
raw string "some_string" unchanged; place this alongside the existing tests
(same file) to prevent regressions when registry types change.
- Around line 157-160: Update the unit test for CLI feature flag parsing by
adding cases that exercise whitespace normalization: in
tests-unit/feature_flags_test.py modify or add to test_empty_key_skipped so
monkeypatch sets comfy_api.feature_flags.args.feature_flag to include strings
like "  show_signin_button = true  " and "   =value" (in addition to the
existing "=value" and "valid=1"), then call _parse_cli_feature_flags() and
assert the result contains {"show_signin_button":"true","valid":"1"} while
empty-key entries are skipped; reference the _parse_cli_feature_flags function
and the test_empty_key_skipped test to locate where to change the input and
expected output.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: e94d9cb1-1b91-4f9c-b22b-46cc6a7edb56

📥 Commits

Reviewing files that changed from the base of the PR and between ce2f848 and 7d4fb09.

📒 Files selected for processing (2)

• comfy_api/feature_flags.py
• tests-unit/feature_flags_test.py

🚧 Files skipped from review as they are similar to previous changes (1)

• comfy_api/feature_flags.py

[guill]

LGTM