fix(help): drop repeated global flags from the appended default-subcommand page

[lu-zero]

Summary

default_subcommand_help (#1424) appends the default child's own --help
page below the root's own page. That appended page rendered its full
Global flags: section too, so any flag declared global on the root
(e.g. --color) showed twice: once under the root's own Flags: section,
then again under the appended child's Global flags: section.

For example, with:

default_subcommand "install"
default_subcommand_help #true
flag "--color" global=#true
cmd "install" {
    flag "-u --update"
}
cmd "query" {}

ex --help used to print --color twice — once on the root's own page,
once again under the appended install page's Global flags: section.
It now prints once, on the root's page only.

Why this is safe as a blanket suppression, not per-flag filtering

The appended child page's only ancestor is always the root itself (the
append only ever happens for the root's immediate default child), so its
Global flags: section is always an exact subset of what the root's own
Flags: section — printed directly above it — already showed: hidden
flags are excluded from both, and a same-spelling child flag shadowing an
inherited one only removes an entry, never introduces a new one that
wasn't on the root's page. So the fix drops the appended page's
Global flags: section outright rather than diffing flag identities.

Changes

• argv/src/help.rs: threads a suppress_global flag through
  rendered_page/short_sections/long_sections/help_structure, set
  only for the nested render inside with_default_command_help. Every
  other caller (standalone pages, --help-all, help topics) is
  unaffected.
• go/argv/page.go / page_long.go: the same fix in the Go renderer,
  which has the same append structure.
• conformance/tests/default_subcommand_help.rs and
  go/argv/page_test.go: regression tests with a global root flag,
  asserting it appears once and the appended page has no Global flags:
  heading.
• docs/spec/reference/index.md: corrected the claim that the appended
  page is identical to the child's standalone --help page — it no
  longer is, by design.

Test plan

• cargo test --all --all-features
• cargo clippy -p usage-argv -p usage-conformance --all-features -- -D warnings
• cargo fmt --check
• go build ./... && go vet ./... && go test ./... (in go/)
• gofmt -l . (in go/)

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Default-command help no longer repeats the parent command’s global flags in short or long help.
  • Appended default-command pages no longer display a redundant “Global flags” section.
  • Parent --help invocations continue parsing at the parent command.

• Documentation

  • Clarified default-command help behavior and parent-level --help parsing in the reference documentation.

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between 1e6eaf5 and c46e125.

📒 Files selected for processing (2)

• conformance/tests/default_subcommand_help.rs
• go/argv/page_test.go

🚧 Files skipped from review as they are similar to previous changes (2)

• go/argv/page_test.go
• conformance/tests/default_subcommand_help.rs

Included review availability: Your plan provides up to 4 included reviews per hour; 2 remain after this review.

---

📝 Walkthrough

Walkthrough

The change adds suppression control to Rust and Go help renderers. Appended default-command pages no longer repeat inherited global flags or render a Global flags: section. Standalone help pages retain existing behavior. Tests and documentation cover the change.

Changes

Default-command help rendering

Layer / File(s)	Summary
Rust help suppression argv/src/help.rs	The Rust help pipeline propagates suppress_global. Appended default-command pages discard inherited flags, while other help paths pass false.
Go help suppression go/argv/page.go, go/argv/page_long.go	Go short and long help rendering accepts suppression control. The appended default-command page uses it, while standalone and all-help paths preserve global flags.
Behavior validation and reference conformance/tests/default_subcommand_help.rs, go/argv/page_test.go, docs/spec/reference/index.md	Tests verify that the root page lists --color and the appended page omits both --color and Global flags:. The reference documentation describes this behavior.

Priority: ⬇️ Low

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Bug fix

Sequence Diagram(s)

sequenceDiagram
  participant RootHelp
  participant with_default_command_help
  participant ChildPageRenderer
  RootHelp->>with_default_command_help: append default-command help
  with_default_command_help->>ChildPageRenderer: render child page with suppressGlobal=true
  ChildPageRenderer-->>with_default_command_help: return page without inherited global flags
  with_default_command_help-->>RootHelp: append child page after root help

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Merge Risk: ⚪ Minimal · up to c46e1

The help output change preserves root global flags while preventing their duplication in appended default-command help. No actionable merge-blocking risk remains.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 38.10% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 21 functions across 5 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
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.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: removing repeated global flags from the appended default-subcommand help page.

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Actionable comments posted: 2

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Inline comments:
In `@argv/src/help.rs`:
- Around line 1813-1830: Add a conformance assertion covering short_help through
with_default_command_help: verify the root short-help page lists the root global
flag exactly once, while the appended default-command page contains neither that
duplicate flag nor the “Global flags:” section.

In `@go/argv/page.go`:
- Around line 420-429: Add a short-help regression assertion in
TestDefaultSubcommandHelpDoesNotRepeatRootGlobalFlags, or the corresponding
short-help test fixture, using a root global flag. Verify the root section
includes that flag while the appended child page omits it, preserving the
existing long-help coverage and child-page behavior.

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---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Central YAML (base), Organization UI (inherited)

Review profile: CHILL

Plan: Advanced

Run ID: faf85633-d0ca-4bb9-8bac-5ebc6490d2cc

📥 Commits

Reviewing files that changed from the base of the PR and between 9b4b8cb and 1e6eaf5.

📒 Files selected for processing (6)

• argv/src/help.rs
• conformance/tests/default_subcommand_help.rs
• docs/spec/reference/index.md
• go/argv/page.go
• go/argv/page_long.go
• go/argv/page_test.go

Included review availability: Your plan provides up to 4 included reviews per hour; 3 remain after this review.

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge; the suppression is confined to inherited globals on the immediate default-child page appended beneath the root page.

Summary

This PR removes duplicate inherited global flags from the default subcommand help page appended beneath root help.

• Threads an explicit suppression setting through Rust short, long, and styled help rendering.
• Applies equivalent behavior to the Go short and long renderers.
• Adds Rust and Go regression coverage for both help modes.
• Updates the specification reference to document the intentional difference from standalone child help.

_{Reviews (1) · Last reviewed commit: "test(help): cover short_help in the defa..."}