chore: gate http import behind feature

[Ocheretovich]

Guards http::header::HeaderName import behind the http feature flag to avoid pulling the dependency when the feature is disabled

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 94.86%. Comparing base (f66b69d) to head (a59b999).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #59   +/-   ##
=======================================
  Coverage   94.86%   94.86%           
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  Files          37       37           
  Lines        3855     3855           
  Branches     3855     3855           
=======================================
  Hits         3657     3657           
  Misses        171      171           
  Partials       27       27           

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[Copilot]

Pull request overview

This PR ensures the http dependency is only pulled in when the http feature is explicitly enabled, reducing unnecessary dependencies for users who don't need HTTP header validation functionality.

Changes:

• Moved http from dev-dependencies to optional dependencies
• Updated the http feature flag to include dep:http, properly gating the dependency

[Nugine]

pulling the dependency when the feature is disabled

The dep path is const-str -> const-str-proc-macro -> http (main branch). I guess it should not happen. Is there any reproduction?

const-str/crates/const-str-proc-macro/src/lib.rs

Lines 64 to 74 in f66b69d

	/// Returns a compile-time verified header name string literal.
	#[cfg(feature = "http")]
	#[proc_macro]
	pub fn verified_header_name(input: TokenStream) -> TokenStream {
	use http::header::HeaderName;
	direct_convert(input, |s: &LitStr| {
	let s = s.value();
	HeaderName::from_lowercase(s.as_bytes()).map(|_| s)
	})
	}

[Nugine]

pulling the dependency when the feature is disabled

The original problem described in this PR needs reproduction.

[Ocheretovich]

I can reproduce the original issue on main by running:

cargo tree -p const-str

which shows http pulled via const-str -> const-str-proc-macro -> http.

After this change, with features disabled:

cargo clean
cargo build -p const-str --no-default-features
cargo tree -p const-str

http is no longer present in the dependency graph.

The proc-macro side is gated via cfg(feature = "http") and the root crate feature now explicitly includes dep:http, so the dependency should only be pulled when --features http is enabled

[Nugine]

The optional dev-dependencies problem: rust-lang/cargo#1596

So the fix looks reasonable. You can also change the other dev-dependencies.

The fix does not affect downstream users.