Fix some clippy lints #138

alanhdu · 2018-10-16T19:01:56Z

I went ahead and fixed all the clippy lints (there were a couple I thought would be better unfixed and added cfg statements to allow them) and also re-enabled clippy and rustfmt in CI.

They were disabled with no time to explain, disable clippy checks, so hopefully this won't go against whatever the reason at the time was 😆.

One question about the CI though: right now, it's an allowed failure that runs against the latest nightly each time. Would it be better to pin it to a specific nightly (or use the beta versions) to lower the churn?

matklad · 2018-10-16T20:13:06Z

They were disabled with no time to explain, disable clippy checks, so hopefully this won't go against whatever the reason at the time was laughing.

At that time, I was transitioning to the to the new implementation of the syntax tree, so that code churn rate was high enough for clippy & rustfmt being a significant problem.

Overall, I am torn about this, curious what other folks think. Here are my rough thoughts about the issue.

I definitely don't want to gate PRs on clippy and rustfmt: to me, additional per-PR code improvements that these tools bring feel much less important that annoyance and additional waiting time for the PR.

I do want to use rustfmt and, to a lesser extend, clippy. These tools do improve code quality in minor-to-moderate ways. At the same time, I am not too keen on keeping a clean git history, especially since GitHub implemented the feature to get the previous blame. So applying suggestions manually from time to time seems fine by me.

I am annoyed by some of the clippy suggestions, which make the code worse :) In particular:

needless_pass_by_value is often very intentional and important for correctness. For example, when passing Senders around the moment when the last Sender is dropped is important, because it tears down the receiver and allows to wait for it.
Minor changes to boolean expressions like !(idx < container.len()) to idx >= container.len() could make the code less readable. In this case, idx < container.len() is the usual invariant, and ! very cleary states "invariant does not hold".
The .map(|&it| it) to .cloned() changes obscure the fact that it is almost-zero const operation, because the type is Copy.

I am also not thrilled by the idea of disabling clippy lints on a case-by-case bases. Is there perhaps some kind of conservative unopinionated clippy profile, that could be applied on the project level?

DJMcNab · 2018-10-16T20:17:47Z

I think we should enforce rustfmt in ci, but then just run clippy every so often if we find a good set of options.

matklad · 2018-10-16T20:22:33Z

I think we should enforce rustfmt in ci,

@DJMcNab why would be more useful than, say, running rusfmt once a week and adding

add this to .git/hooks/pre-commit to run rustfmt automatically on save

cargo fmt-changes

where fmt-changes is a command which applies rustfmt to changed files?

I think it's a bad contributor experience when you PR fails just because you've forgotten a trailing comma, or use a different version of rustfmt.

DJMcNab · 2018-10-16T21:33:04Z

Different rustfmt version is a good point. I guess I've been spoiled by the ecosystem around nodejs, especially prettier combined with husky and vscode that I think of formatting as a non-issue.

The Rust formatting ecosystem isn't quite there yet, unfortunately, so maybe it would be better to format every so often. I wonder if bors can handle rustfmting automatically somehow...

CAD97 · 2018-10-16T22:21:18Z

You can (but shouldn't) make CI commit and push to the repo.

Maybe someone could set up a bot that does fmt PRs?

(Personally, I enforce a pinned stable rustfmt. I think it's better to require standard formatting always, which keeps git-blame accurate. The CI job is named so it's simple to see why it failed.)

alanhdu · 2018-10-17T23:37:46Z

Definitely here you about some of the lints -- I've rebased this branch and only cherry-picked the Clippy lints that I think are probably unobjectionable.

Is there perhaps some kind of conservative unopinionated clippy profile, that could be applied on the project level?

I think so, but it looks like there's no way to configure it on a per-repo level and you need to add [cfg] statements per-crate -- surprisingly, it doesn't look like there's a way to do per-repo configuration via a toml file somewhere (at least based on rust-lang/cargo#5034 and rust-lang/rust-clippy#1313).

I think not-having clippy in CI and only doing it "once in a while" is probably a good choice until lints can be configured centrally and not per-crate. I think it's reasonable to do rustfmt in CI, but don't feel strongly (for the Rust projects I work on, we have a "blessed" version of Rust to develop on, and we use the corresponding rustfmt that's rustup distributes with that version).

Because it's a stateful iterator, it's easier to explicitly clone it when necesary. Fixes clippy:clone_on_copy

Manually implement PartialEq

alanhdu · 2018-10-18T14:06:54Z

I guess we could also configure clippy through the command line:

cargo +nightly clippy -- -A clippy::style -A clippy::nonminimal_bool

seems to work fine.

matklad · 2018-10-19T09:22:50Z

I think not-having clippy in CI and only doing it "once in a while" is probably a good choice until lints can be configured centrally and not per-crate. I think it's reasonable to do rustfmt in CI, but don't feel strongly (for the Rust projects I work on, we have a "blessed" version of Rust to develop on, and we use the corresponding rustfmt that's rustup distributes with that version).

Don't have time for a thorough respose, but if that could make work via a script in tasks which makes sure the relevant version of rustfmt is installed, etc, such that the end user can

$ git clone rust-analyzer && cd rust-analyzer
$ cargo reformat

and that there's a test in ci/tests, which fails during cargo test, that could work, yeah.

matklad · 2018-10-20T12:57:01Z

crates/ra_editor/src/scope/fn_scope.rs

@@ -88,7 +88,7 @@ pub struct ScopeEntry {
 }

 impl ScopeEntry {
-    fn new(pat: ast::BindPat) -> Option<ScopeEntry> {
+    fn new_opt(pat: ast::BindPat) -> Option<ScopeEntry> {


Let's use new to name such methods? It's what stdlib does, so it looks like a bug in clippy:

https://doc.rust-lang.org/std/ffi/struct.CString.html#method.new

Looks like this will be fixed with rust-lang/rust-clippy#3338

matklad · 2018-10-20T12:58:14Z

crates/ra_analysis/src/job.rs

@@ -11,7 +11,7 @@ pub struct JobToken {
 }

 impl JobHandle {
-    pub fn new() -> (JobHandle, JobToken) {
+    pub fn new_pair() -> (JobHandle, JobToken) {


Agree that new probably isn't the best name here, the whole JobHandle infra will be removed once we finish migration to salsa.

This reverts commit 2ae9dfa.

matklad · 2018-10-22T18:36:44Z

bors r+

Thanks!

138: Fix some clippy lints r=matklad a=alanhdu I went ahead and fixed all the clippy lints (there were a couple I thought would be better unfixed and added `cfg` statements to allow them) and also re-enabled clippy and rustfmt in CI. They were disabled with `no time to explain, disable clippy checks`, so hopefully this won't go against whatever the reason at the time was 😆. One question about the CI though: right now, it's an allowed failure that runs against the latest nightly each time. Would it be better to pin it to a specific nightly (or use the `beta` versions) to lower the churn? Co-authored-by: Alan Du <[email protected]>

bors · 2018-10-22T22:00:40Z

Build succeeded

continuous-integration/travis-ci/push

matklad · 2018-10-23T13:39:00Z

Filed #155 for rustfmt

alanhdu force-pushed the clippy branch from a21c07a to f88c1ce Compare October 17, 2018 23:32

alanhdu added 9 commits October 17, 2018 19:42

Clippy lint: single-character string constant

5db663d

clippy: Use if lets and remove redundant returns

d493a44

Remove Copy trait on LeafAtOffset

4e8ea94

Because it's a stateful iterator, it's easier to explicitly clone it when necesary. Fixes clippy:clone_on_copy

Silence clippy::derive_hash_xor_eq

2268a2f

Manually implement PartialEq

clippy: Fix new_ret_no_self

2ae9dfa

clippy: needless_lifetimes

bc774fe

clippy: type_complexity

fc8024d

Fix function calls

a5da770

clippy: cast_lossless

6dd3fa6

alanhdu force-pushed the clippy branch from f88c1ce to 6dd3fa6 Compare October 17, 2018 23:42

alanhdu changed the title ~~Turn clippy and rustfmt on in CI again~~ Fix some clippy lints Oct 17, 2018

matklad reviewed Oct 20, 2018

View reviewed changes

alanhdu added 2 commits October 20, 2018 12:29

Revert "clippy: Fix new_ret_no_self"

0857c22

This reverts commit 2ae9dfa.

Rename new to new_item (to match new_impl)

dc9ce8f

bors bot merged commit dc9ce8f into rust-lang:master Oct 22, 2018

alanhdu deleted the clippy branch October 22, 2018 23:55

sify21 mentioned this pull request Sep 16, 2020

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Fix some clippy lints #138

Fix some clippy lints #138

alanhdu commented Oct 16, 2018

matklad commented Oct 16, 2018

DJMcNab commented Oct 16, 2018

matklad commented Oct 16, 2018

DJMcNab commented Oct 16, 2018

CAD97 commented Oct 16, 2018

alanhdu commented Oct 17, 2018

alanhdu commented Oct 18, 2018

matklad commented Oct 19, 2018

matklad Oct 20, 2018

alanhdu Oct 22, 2018

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matklad commented Oct 22, 2018

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matklad commented Oct 23, 2018

Fix some clippy lints #138

Fix some clippy lints #138

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alanhdu commented Oct 16, 2018

matklad commented Oct 16, 2018

DJMcNab commented Oct 16, 2018

matklad commented Oct 16, 2018

DJMcNab commented Oct 16, 2018

CAD97 commented Oct 16, 2018

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Build succeeded

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