Fix workspace clippy lints

[Abeeujah]

Running cargo clippy --all-features --all-targets --locked -- -D warnings triggers common places code could be improved. This PR fixes the lightning-macros and lightning-invoice crate.

[ldk-reviews-bot]

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[ldk-claude-review-bot]

This #[allow(clippy::type_complexity)] is redundant — ci/check-lint.sh already globally suppresses clippy::type_complexity with -A clippy::type_complexity (line 99). Adding per-function #[allow] attributes just adds noise without any effect under the project's CI configuration.

[ldk-claude-review-bot]

Review Summary

Every clippy lint fixed in this PR is already suppressed in ci/check-lint.sh. The author ran cargo clippy -- -D warnings without the project's standard allow flags, so all these warnings appeared — but under the actual CI configuration, none of these lints are enforced.

Cross-referencing each change against ci/check-lint.sh:

Change	Clippy lint	CI line
Doc comment tabs → spaces	tabs_in_doc_comments	line 95
#[allow(clippy::type_complexity)] additions	type_complexity	line 99
.map(|tf| Ctor(tf)) → .map(Ctor)	redundant_closure	line 83
match { => true, _ => false } → matches!()	match_like_matches_macro	line 61
.map().flatten() → .flat_map() / .and_then()	map_flatten	line 60
&vec → vec, &chunk → chunk, etc.	needless_borrow	line 66
u64::max_value() → u64::MAX	legacy_numeric_constants	line 47
.skip(2).next() → .nth(2)	iter_skip_next	line 45
Nested if → combined condition	collapsible_if	line 29

None of these changes affect CI pass/fail. The individual transformations are logically correct (no bugs introduced), but they create unnecessary code churn — particularly the doc comment whitespace changes which touch many lines across multiple files.

Inline comments posted:

• lightning-invoice/src/lib.rs:1144 — #[allow(clippy::type_complexity)] is redundant since the lint is already globally suppressed in CI

Cross-cutting concern: If the goal is to clean up these lints, the proper approach would be to fix ALL instances of a given lint workspace-wide, then remove the corresponding -A clippy::... entry from ci/check-lint.sh so the lint is enforced going forward. Partially fixing suppressed lints in a few crates doesn't improve CI coverage and risks merge conflicts with other in-flight work.

[TheBlueMatt]

I mean, sure, seems fine to fix modulo claude's above comment.

[Abeeujah]

If the goal is to clean up these lints, the proper approach would be to fix ALL instances of a given lint workspace-wide, then remove the corresponding -A clippy::... entry from ci/check-lint.sh so the lint is enforced going forward.

I mean, sure, seems fine to fix modulo claude's above comment.

The goal is to clean up workspace-wide, but in lightning crate alone:

warning: `lightning` (lib) generated 1951 warnings (123 duplicates)
error: could not compile `lightning` (lib) due to 5 previous errors; 1951 warnings emitted

Before investing effort into that, I think it would be important to know if these lints were supressed intentionally for DX?

[codecov]

Codecov Report

❌ Patch coverage is 78.26087% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.43%. Comparing base (71fdc27) to head (2932ee7).

Files with missing lines	Patch %	Lines
lightning-invoice/src/lib.rs	78.57%	2 Missing and 1 partial ⚠️
lightning-types/src/features.rs	66.66%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4617      +/-   ##
==========================================
- Coverage   86.44%   86.43%   -0.02%     
==========================================
  Files         159      159              
  Lines      109823   109803      -20     
  Branches   109823   109803      -20     
==========================================
- Hits        94941    94903      -38     
- Misses      12340    12356      +16     
- Partials     2542     2544       +2     

Flag	Coverage Δ
fuzzing-fake-hashes	5.08% <0.00%> (+<0.01%)	⬆️
fuzzing-real-hashes	22.78% <0.00%> (+<0.01%)	⬆️
tests	86.16% <78.26%> (-0.03%)	⬇️

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[TheBlueMatt]

There's a few that were suppressed cause clippy is outright wrong, but most of them are because clippy wasn't run until way after this repo existed and most clippy lints aren't really worth fixing. I don't think it makes sense to go through the repo and fix 1951 places where clippy is complaining about whitespace (or other unimportant issues). There's probably some individual lints that are worth fixing, but I haven't looked in a while at what we're ignoring that might be worth it.

[Abeeujah]

There's a few that were suppressed cause clippy is outright wrong

Seen those, wouldn't be bothering with that.

I don't think it makes sense to go through the repo and fix 1951 places where clippy is complaining about whitespace (or other unimportant issues).

I wouldn't be prioritizing these, but the goal here, is it helps me grok the codebase, while also improving what's could be improved upon.

There's probably some individual lints that are worth fixing, but I haven't looked in a while at what we're ignoring that might be worth it.

Yeah, going through the allowed lints, there's a couple cases worth fixing that could impact performance and code quality. would start from those.

@TheBlueMatt Please I tried pinging you on Discord (Abeeujah).