fix(lib): add missing child node support to arg parser

[jdx]

Summary

• Add support for help, long_help, help_long, help_md, required, var, var_min, var_max, hide, and double_dash as child nodes inside {} blocks for arg definitions
• Previously only choices, env, and default were supported as child nodes, causing parse errors for other properties
• Matches the existing pattern used in SpecFlag::parse()

Test plan

• Added test_arg_child_nodes test verifying help, choices, var, and var_min as child nodes
• Added test_arg_long_help_child_node test verifying help and long_help as child nodes
• All 153 usage-lib tests pass

🤖 Generated with Claude Code

---

Note

Low Risk
Additive parsing support in SpecArg::parse plus tests; low risk aside from potentially changing behavior for specs that previously errored or relied on unsupported child nodes.

Overview
SpecArg::parse now accepts common argument attributes (e.g. help, long_help/help_long, help_md, required, var + var_min/var_max, hide, double_dash) as child nodes inside arg { ... } blocks, instead of erroring on them.

Adds new tests verifying mixed child-node parsing (including choices) and long_help parsing for args.

^{Written by Cursor Bugbot for commit bcb2fa9. This will update automatically on new commits. Configure here.}

[gemini-code-assist]

Summary of Changes

Hello @jdx, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request significantly enhances the flexibility of argument definitions by extending the parser to recognize a wider range of properties as child nodes. This change resolves previous limitations where only a few properties were supported, ensuring that arg definitions can now be more comprehensively configured directly within their blocks, leading to a more robust and consistent parsing experience across the library.

Highlights

• Expanded arg definition support: Added support for help, long_help, help_long, help_md, required, var, var_min, var_max, hide, and double_dash as child nodes within {} blocks for arg definitions.
• Improved parser consistency: The arg parser now aligns with the existing pattern used in SpecFlag::parse(), resolving previous parse errors for these properties.
• New test coverage: Introduced test_arg_child_nodes and test_arg_long_help_child_node to verify the correct parsing of these new child node properties.

Changelog

• lib/src/spec/arg.rs
  • Extended the SpecArg::parse method to handle additional child node properties such as help, long_help, required, var, var_min, var_max, hide, and double_dash.
  • Added new unit tests (test_arg_child_nodes and test_arg_long_help_child_node) to validate the correct parsing and assignment of these newly supported child node properties.

Activity

• No human activity has been recorded on this pull request yet.

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[Copilot]

Pull request overview

This PR adds support for additional child nodes (help, long_help, help_long, help_md, required, var, var_min, var_max, hide, double_dash) inside {} blocks for arg definitions in the argument parser. Previously, only choices, env, and default were supported as child nodes.

Changes:

• Extended SpecArg::parse() to handle 10 additional child node types
• Added comprehensive test coverage for the new child node support

---

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[Copilot]

Both long_help and help_long set the same field arg.help_long. This duplication suggests these are aliases, but it creates ambiguity about which one is the canonical name. Consider documenting this aliasing behavior or consolidating to a single name to improve clarity.

[gemini-code-assist]

Code Review

This pull request correctly adds support for several previously unsupported child nodes in arg definitions, improving consistency within the parser. The changes are accompanied by new tests. I have two suggestions: one to refactor a small piece of duplicated code using an or-pattern, and another to enhance the new tests to cover both aliases for long_help, ensuring better test coverage.

[gemini-code-assist]

To improve maintainability and reduce code duplication, you can use an or-pattern to handle both long_help and help_long in a single match arm.

Suggested change

	"long_help" => arg.help_long = Some(child.arg(0)?.ensure_string()?),
	"help_long" => arg.help_long = Some(child.arg(0)?.ensure_string()?),
	"long_help" | "help_long" => arg.help_long = Some(child.arg(0)?.ensure_string()?),

[gemini-code-assist]

To improve test coverage, this test should verify that both long_help and its alias help_long are parsed correctly as child nodes. You can do this by adding another argument definition to the spec string and asserting its properties.

    fn test_arg_long_help_child_node() {
        let spec = Spec::parse(
            &Default::default(),
            r#"
arg "<input>" {
    help "Input file"
    long_help "Extended help text for input"
}
arg "<input2>" {
    help "Input file 2"
    help_long "Extended help text for input 2"
}
            "#,
        )
        .unwrap();

        let input_arg = spec.cmd.args.iter().find(|a| a.name == "input").unwrap();
        assert_eq!(input_arg.help, Some("Input file".to_string()));
        assert_eq!(input_arg.help_long, Some("Extended help text for input".to_string()));

        let input_arg2 = spec.cmd.args.iter().find(|a| a.name == "input2").unwrap();
        assert_eq!(input_arg2.help, Some("Input file 2".to_string()));
        assert_eq!(input_arg2.help_long, Some("Extended help text for input 2".to_string()));
    }

[codecov]

Codecov Report

❌ Patch coverage is 81.13208% with 10 lines in your changes missing coverage. Please review.
✅ Project coverage is 69.58%. Comparing base (1a9a880) to head (bcb2fa9).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/src/spec/arg.rs	81.13%	3 Missing and 7 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #489      +/-   ##
==========================================
- Coverage   70.71%   69.58%   -1.13%     
==========================================
  Files          47       47              
  Lines        6716     6789      +73     
  Branches     6716     6789      +73     
==========================================
- Hits         4749     4724      -25     
- Misses       1277     1299      +22     
- Partials      690      766      +76     

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