#deno #lint #box

deno_lint

lint for deno

45 releases

0.2.18 Feb 11, 2021
0.2.14 Dec 21, 2020
0.2.12 Nov 30, 2020
0.1.20 Jul 31, 2020
Download history 3441/week @ 2020-11-07 2688/week @ 2020-11-14 3860/week @ 2020-11-21 3284/week @ 2020-11-28 3997/week @ 2020-12-05 4755/week @ 2020-12-12 2235/week @ 2020-12-19 2537/week @ 2020-12-26 4432/week @ 2021-01-02 3946/week @ 2021-01-09 3653/week @ 2021-01-16 4302/week @ 2021-01-23 2775/week @ 2021-01-30 3061/week @ 2021-02-06 4235/week @ 2021-02-13 2959/week @ 2021-02-20

14,925 downloads per month
Used in 2 crates

MIT license

1MB
34K SLoC

deno_lint

A Rust crate for writing fast JavaScript and TypeScript linters.

This crate powers deno lint, but is not Deno specific and can be used to write linters for Node as well.

Supports recommended set of rules from ESLint and @typescript-eslint out of the box with no config.

See the roadmap


Supported rules

Visit https://lint.deno.land for the list of available rules.

Performance

Blazing fast, see comparison with ESLint:

[
  {
    "name": "deno_lint",
    "totalMs": 105.3750100000002,
    "runsCount": 5,
    "measuredRunsAvgMs": 21.07500200000004,
    "measuredRunsMs": [
      24.79783199999997,
      19.563640000000078,
      20.759051999999883,
      19.99068000000011,
      20.26380600000016
    ]
  },
  {
    "name": "eslint",
    "totalMs": 11845.073306000002,
    "runsCount": 5,
    "measuredRunsAvgMs": 2369.0146612000003,
    "measuredRunsMs": [
      2686.1039550000005,
      2281.501061,
      2298.6185210000003,
      2279.5962849999996,
      2299.2534840000008
    ]
  }
]

Benchmarks are run during CI on Ubuntu, using the same set of rules for both linters. Test subject is oak server consisting of about 50 files. See ./benchmarks/ directory for more info.

Example

examples/dlint/main.rs provides a minimal standalone binary demonstrating how deno_lint can be used as a crate.

# Build standalone binary
$ cargo build --example dlint

$ ./target/debug/examples/dlint --help

dlint

USAGE:
    dlint <SUBCOMMAND>

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information

SUBCOMMANDS:
    help     Prints this message or the help of the given subcommand(s)
    rules
    run

$ ./target/debug/examples/dlint run ../deno/std/http/server.ts ../deno/std/http/file_server.ts
(no-empty) Empty block statement
  --> ../deno/std/http/server.ts:93:14
   |
93 |       } catch {}
   |               ^^
   |
(no-empty) Empty block statement
   --> ../deno/std/http/server.ts:111:44
    |
111 |     while ((await body.read(buf)) !== null) {}
    |                                             ^^
    |
(no-empty) Empty block statement
   --> ../deno/std/http/server.ts:120:41
    |
120 |   constructor(public listener: Listener) {}
    |                                          ^^
    |
(ban-untagged-todo) TODO should be tagged with (@username) or (#issue)
 --> ../deno/std/http/file_server.ts:5:0
  |
5 | // TODO Stream responses instead of reading them into memory.
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
(ban-untagged-todo) TODO should be tagged with (@username) or (#issue)
 --> ../deno/std/http/file_server.ts:6:0
  |
6 | // TODO Add tests like these:
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
(ban-untagged-todo) TODO should be tagged with (@username) or (#issue)
   --> ../deno/std/http/file_server.ts:137:0
    |
137 | // TODO: simplify this after deno.stat and deno.readDir are fixed
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
(no-empty) Empty block statement
   --> ../deno/std/http/file_server.ts:155:16
    |
155 |     } catch (e) {}
    |                 ^^
    |
Found 7 problems

For more concrete implementation visit deno

Developing

Make sure to have latest stable version of Rust installed (1.49.0).

// check version
$ rustc --version
rustc 1.49.0 (e1884a8e3 2020-12-29)

// build all targets
$ cargo build --all-targets

// test it
$ cargo test

Generating flamegraph (Linux)

Prerequisites:

$ RUSTFLAGS='-g' cargo build --release --all-targets # build target
$ sudo perf record --call-graph dwarf ./target/release/examples/dlint benchmarks/oak/**.ts # create performance profile
$ perf script | stackcollapse-perf | rust-unmangle | flamegraph > flame.svg # generate flamegraph

These commands can take a few minutes to run.

Contributing

Submitting a Pull Request

Before submitting, please make sure the following is done:

  1. That there is a related issue and it is referenced in the PR text.
  2. There are tests that cover the changes.
  3. Ensure cargo test passes.
  4. Format your code with deno run --allow-run tools/format.ts
  5. Make sure deno run --allow-run tools/lint.ts passes.

Dependencies

~6.5MB
~154K SLoC