Blazing fast linter for JavaScript and TypeScript written in Rust

Deno Land

Last update: Dec 29, 2022

Overview

`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.

Node.js bindings

If you want to use deno_lint with Node, please refer to @node-rs/deno-lint package which provides programmatic API as well as Webpack loader for deno_lint.

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 (1.56.0).

// check version
$ rustc --version
rustc 1.56.0 (09c42c458 2021-10-18)

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

// test it
$ cargo test

Generating flamegraph (Linux)

Prerequisites:

Install perf, stackcollapse-perf, c++filt and flamegraph

$ 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 | c++filt | flamegraph > flame.svg # generate flamegraph

You can use rust-unmangle or rustfilt instead of c++filt.

These commands can take a few minutes to run.

Contributing

If you are going to work on an issue, mention so in the issue comments before you start working on the issue.
Please be professional in the forums. We follow Rust's code of conduct (CoC) Have a problem? Email [email protected].
Ask for help in the community chat room.

Submitting a Pull Request

Before submitting, please make sure the following is done:

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

Comments

add Camelcase rule

~~work in progress~~

In this PR, I implemented the camelcase rule. https://eslint.org/docs/rules/camelcase Besides I ported all the tests from ESLint, and they are all passed.

Closes #301

opened by magurotuna 37
ESLint recommended rules
Tracking issue for rules from eslint:recommended set.

[x] constructor-super

[x] for-direction

[x] getter-return

[x] no-async-promise-executor

[x] no-case-declarations

[x] no-class-assign (broken, needs scope analysis)

[x] no-compare-neg-zero

[x] no-cond-assign

[x] no-const-assign (broken, needs scope analysis)

[x] no-constant-condition

[x] no-control-regex (easy)

[x] no-debugger

[x] no-delete-var

[x] no-dupe-args

[x] no-dupe-class-members

[x] no-dupe-else-if

[x] no-dupe-keys

[x] no-duplicate-case

[x] no-empty

[x] no-empty-character-class

[x] no-empty-pattern

[x] no-ex-assign (broken, needs scope analysis)

[x] no-extra-boolean-cast

[x] no-extra-semi

[x] no-fallthrough (hard, needs code path analysis)

[x] no-func-assign (broken, needs scope analysis)

[x] no-global-assign (hard, needs scope analysis)

[x] no-import-assign (hard, needs scope analysis)

[x] no-inner-declarations

[x] no-invalid-regexp(~~easy~~ hard, need to port additional lib)

[x] no-irregular-whitespace (easy)

[ ] no-misleading-character-class (easy)

[x] no-mixed-spaces-and-tabs

[x] no-new-symbol

[x] no-obj-calls

[x] no-octal

[x] no-prototype-builtins

[x] no-redeclare (hard, needs scope analysis)

[x] no-regex-spaces

[x] no-self-assign

[x] no-setter-return

[x] no-shadow-restriced-names

[x] no-sparse-arrays

[x] no-this-before-super

[x] no-undef (hard, needs scope analysis)

[x] no-unexpected-multiline (easy)

[x] no-unreachable (hard, needs code path analysis)

[x] no-unsafe-finally

[x] no-unsafe-negation

[x] no-unused-labels

[x] no-unused-vars (hard, needs scope analysis)

[x] no-useless-escape (easy) (https://github.com/denoland/deno_lint/issues/48#issuecomment-666285937)

[x] no-with

[x] require-yield

[x] use-isnan

[x] valid-typeof

epic
opened by bartlomieju 19
getter-return and infinite loops
The following code produces "Getter requires a return deno-lint(getter-return)" despite the return statement. I wonder if it's possible for the linter to recognize that the only way out of the loop and out of the function is through the return?

I would have just ignored the linter and not opened an issue except that the linter clearly recognizes that the last line when uncommented is redundant since uncommenting it silences deno-lint(getter-return), but produces a deno-lint(no-unreachable) error instead.

get root(): this { // deno-lint-ignore no-this-alias let primary = this; while (true) { if (primary.parent !== undefined) { primary = primary.parent; } else { return primary; } } //return this; }

deno 1.4.0 v8 8.7.75 typescript 4.0.2 VS Code extension 2.3.1

I'm fine with a "Won't Fix" on this BTW.
opened by callionica 14

Feature Request: Webpack Loader for Deno Lint

I think it would be great if we have a webpack loader for deno lint, and would be configurable to break the build whenever it encounters a lint error

example webpack configuration:

{
                    test: /\.(ts|js)$/,
                    enforce: "pre",
                    loader: "deno-lint-loader",
                    options: {
                        emitErrors: true,
                        failOnHint: true
                    }
                }

request

opened by jetfontanilla 14

Errors reported twice by dlint.

Lint Name

All, or at least most.

Code Snippet

for(var x;;);

Expected Result

error[no-inner-declarations]: Move variable declaration to module root
 --> C:\...\test-script.js:1:5
  |
1 | for(var x;;);
  |     ^^^^^
  |
  = help: Move the declaration up into the correct scope
Found 1 problem

Actual Result

error[no-inner-declarations]: Move variable declaration to module root
 --> C:\...\test-script.js:1:5
  |
1 | for(var x;;);
  |     ^^^^^
  |
  = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to module root
 --> C:\...\test-script.js:1:5
  |
1 | for(var x;;);
  |     ^^^^^
  |
  = help: Move the declaration up into the correct scope
Found 2 problems

Additional Info

This happens for almost all errors reported.

It's strange that this has not be noticed before. Perhaps this is unique to the Windows executable?

Just in case it helps to see more examples, I've added an additional, much larger, output from a module that is constrained to ES3 which produces a variety of linting errors (in part because it's been coded for easy transformation to ES2015+ as soon as we can get rid of a very old host-side JS runtime in production).

Version

dlint 0.6.0

Additional Results

C:\...\build\code>cls & dlint run --config=C:\...\build\$DenoLintRules.json C:\...\business\code\libweb\src\util\GeneralUtil.js

error[no-inner-declarations]: Move variable declaration to function root
  --> C:\...\src\util\GeneralUtil.js:90:9
   |
90 |     for(var xa=0; xa<fncs.length; ++xa) {
   |         ^^^^^^^^
   |
   = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
  --> C:\...\src\util\GeneralUtil.js:90:9
   |
90 |     for(var xa=0; xa<fncs.length; ++xa) {
   |         ^^^^^^^^
   |
   = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
  --> C:\...\src\util\GeneralUtil.js:99:17
   |
99 |             for(var xa=0,len=fncs.length; xa<len; ++xa) { fncs[xa].apply(null,args); }
   |                 ^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
  --> C:\...\src\util\GeneralUtil.js:99:17
   |
99 |             for(var xa=0,len=fncs.length; xa<len; ++xa) { fncs[xa].apply(null,args); }
   |                 ^^^^^^^^^^^^^^^^^^^^^^^^
   |
   = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:189:17
    |
189 |             for(var xa=0,len=cmpfncs.length; xa<len && cmpres==0; ++xa) { cmpres=cmpfncs[xa](onercd,tworcd); }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:189:17
    |
189 |             for(var xa=0,len=cmpfncs.length; xa<len && cmpres==0; ++xa) { cmpres=cmpfncs[xa](onercd,tworcd); }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-extra-semi]: Unnecessary semicolon.
   --> C:\...\src\util\GeneralUtil.js:230:10
    |
230 |         };
    |          ^
    |
    = help: Remove the extra (and unnecessary) semi-colon
error[no-extra-semi]: Unnecessary semicolon.
   --> C:\...\src\util\GeneralUtil.js:230:10
    |
230 |         };
    |          ^
    |
    = help: Remove the extra (and unnecessary) semi-colon
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:252:9
    |
252 |     for(var key in obj) {
    |         ^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:252:9
    |
252 |     for(var key in obj) {
    |         ^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-prototype-builtins]: Access to Object.prototype.hasOwnProperty is not allowed from target object
   --> C:\...\src\util\GeneralUtil.js:253:13
    |
253 |         if(!obj.hasOwnProperty(key)) { continue; }
    |             ^^^^^^^^^^^^^^^^^^^^^^^
    |
error[no-prototype-builtins]: Access to Object.prototype.hasOwnProperty is not allowed from target object
   --> C:\...\src\util\GeneralUtil.js:253:13
    |
253 |         if(!obj.hasOwnProperty(key)) { continue; }
    |             ^^^^^^^^^^^^^^^^^^^^^^^
    |
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:254:9
    |
254 |         var val=obj[key];
    |         ^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:254:9
    |
254 |         var val=obj[key];
    |         ^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:299:9
    |
299 |     for(var dft of argsArray(arguments,1)) {
    |         ^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:299:9
    |
299 |     for(var dft of argsArray(arguments,1)) {
    |         ^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:328:9
    |
328 |         var args=argsArray(arguments,2);
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:328:9
    |
328 |         var args=argsArray(arguments,2);
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:344:13
    |
344 |         for(var xa=0, len=arr.length; xa<len; ++xa) {
    |             ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:344:13
    |
344 |         for(var xa=0, len=arr.length; xa<len; ++xa) {
    |             ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:417:21
    |
417 |     if(exctyps) for(var xa=0,len=exctyps.length; xa<len; ++xa) {
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:417:21
    |
417 |     if(exctyps) for(var xa=0,len=exctyps.length; xa<len; ++xa) {
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:489:9
    |
489 |     for(var xa=1,len=arguments.length; xa<len; ++xa ) {
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:489:9
    |
489 |     for(var xa=1,len=arguments.length; xa<len; ++xa ) {
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:515:9
    |
515 |     for(var xa=1,len=arguments.length; xa<len; ++xa) {
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:515:9
    |
515 |     for(var xa=1,len=arguments.length; xa<len; ++xa) {
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:517:13
    |
517 |         for(var keys=Object.keys(src), xb=0; xb<keys.length; xb++) { var key=keys[xb]; tgt[key]=src[key]; }
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:517:70
    |
517 |         for(var keys=Object.keys(src), xb=0; xb<keys.length; xb++) { var key=keys[xb]; tgt[key]=src[key]; }
    |                                                                      ^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:517:13
    |
517 |         for(var keys=Object.keys(src), xb=0; xb<keys.length; xb++) { var key=keys[xb]; tgt[key]=src[key]; }
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:517:70
    |
517 |         for(var keys=Object.keys(src), xb=0; xb<keys.length; xb++) { var key=keys[xb]; tgt[key]=src[key]; }
    |                                                                      ^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:565:9
    |
565 |     for(var xa=1,len=arguments.length; xa<len; ++xa ) {
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:565:9
    |
565 |     for(var xa=1,len=arguments.length; xa<len; ++xa ) {
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-extra-semi]: Unnecessary semicolon.
   --> C:\...\src\util\GeneralUtil.js:634:10
    |
634 |         };
    |          ^
    |
    = help: Remove the extra (and unnecessary) semi-colon
error[no-extra-semi]: Unnecessary semicolon.
   --> C:\...\src\util\GeneralUtil.js:634:10
    |
634 |         };
    |          ^
    |
    = help: Remove the extra (and unnecessary) semi-colon
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:640:9
    |
640 |         var stgval=localStorage.getItem(stgnam);
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:640:9
    |
640 |         var stgval=localStorage.getItem(stgnam);
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-empty]: Empty block statement
   --> C:\...\src\util\GeneralUtil.js:642:75
    |
642 |             try { curval=JSON.parse(stgval).value || curval; } catch(err) {}                                            // ignore error, leaving current value unchanged
    |                                                                           ^^
    |
    = help: Add code or comment to the empty block
error[no-empty]: Empty block statement
   --> C:\...\src\util\GeneralUtil.js:642:75
    |
642 |             try { curval=JSON.parse(stgval).value || curval; } catch(err) {}                                            // ignore error, leaving current value unchanged
    |                                                                           ^^
    |
    = help: Add code or comment to the empty block
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:646:9
    |
646 |         var inival=curval;
    |         ^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:646:9
    |
646 |         var inival=curval;
    |         ^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:780:9
    |
780 |     for(var xa=0,len=pths.length; xa<len; ++xa) {
    |         ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:780:9
    |
780 |     for(var xa=0,len=pths.length; xa<len; ++xa) {
    |         ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:781:9
    |
781 |         var pth=pths[xa];
    |         ^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:781:9
    |
781 |         var pth=pths[xa];
    |         ^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:782:9
    |
782 |         var spl=pth.lastIndexOf("/");
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:782:9
    |
782 |         var spl=pth.lastIndexOf("/");
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:783:9
    |
783 |         var par,lea;
    |         ^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:783:9
    |
783 |         var par,lea;
    |         ^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:839:9
    |
839 |         var args=argsArray(arguments,1);                                                                                // include `fnc` which will become the current count
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:839:9
    |
839 |         var args=argsArray(arguments,1);                                                                                // include `fnc` which will become the current count
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:842:13
    |
842 |             var lmt=cnt;
    |             ^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:842:13
    |
842 |             var lmt=cnt;
    |             ^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:845:13
    |
845 |         for(var xa=0; cnt(xa); ++xa) {
    |             ^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:845:13
    |
845 |         for(var xa=0; cnt(xa); ++xa) {
    |             ^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:986:9
    |
986 |     for(var key in obj) {
    |         ^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:986:9
    |
986 |     for(var key in obj) {
    |         ^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-prototype-builtins]: Access to Object.prototype.hasOwnProperty is not allowed from target object
   --> C:\...\src\util\GeneralUtil.js:987:13
    |
987 |         if(!obj.hasOwnProperty(key)) { continue; }
    |             ^^^^^^^^^^^^^^^^^^^^^^^
    |
error[no-prototype-builtins]: Access to Object.prototype.hasOwnProperty is not allowed from target object
   --> C:\...\src\util\GeneralUtil.js:987:13
    |
987 |         if(!obj.hasOwnProperty(key)) { continue; }
    |             ^^^^^^^^^^^^^^^^^^^^^^^
    |
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:988:9
    |
988 |         var val=obj[key];
    |         ^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:988:9
    |
988 |         var val=obj[key];
    |         ^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:998:13
    |
998 |         for(var xa=0,len=srcobj.length; xa<len; ++xa) {
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:998:13
    |
998 |         for(var xa=0,len=srcobj.length; xa<len; ++xa) {
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:999:13
    |
999 |             var srcval=srcobj[xa];
    |             ^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
   --> C:\...\src\util\GeneralUtil.js:999:13
    |
999 |             var srcval=srcobj[xa];
    |             ^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1016:13
     |
1016 |         for(var key in srcobj) {
     |             ^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1016:13
     |
1016 |         for(var key in srcobj) {
     |             ^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-prototype-builtins]: Access to Object.prototype.hasOwnProperty is not allowed from target object
    --> C:\...\src\util\GeneralUtil.js:1017:17
     |
1017 |             if(!srcobj.hasOwnProperty(key)) { continue; }
     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
error[no-prototype-builtins]: Access to Object.prototype.hasOwnProperty is not allowed from target object
    --> C:\...\src\util\GeneralUtil.js:1017:17
     |
1017 |             if(!srcobj.hasOwnProperty(key)) { continue; }
     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
     |
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1018:13
     |
1018 |             var srcval=srcobj[key];
     |             ^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-redeclare]: Redeclaration is not allowed
    --> C:\...\src\util\GeneralUtil.js:1018:17
     |
1018 |             var srcval=srcobj[key];
     |                 ^^^^^^
     |
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1018:13
     |
1018 |             var srcval=srcobj[key];
     |             ^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-redeclare]: Redeclaration is not allowed
    --> C:\...\src\util\GeneralUtil.js:1018:17
     |
1018 |             var srcval=srcobj[key];
     |                 ^^^^^^
     |
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1040:9
     |
1040 |     for(var key in obj) {
     |         ^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1040:9
     |
1040 |     for(var key in obj) {
     |         ^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-prototype-builtins]: Access to Object.prototype.hasOwnProperty is not allowed from target object
    --> C:\...\src\util\GeneralUtil.js:1041:13
     |
1041 |         if(!obj.hasOwnProperty(key)) { continue; }
     |             ^^^^^^^^^^^^^^^^^^^^^^^
     |
error[no-prototype-builtins]: Access to Object.prototype.hasOwnProperty is not allowed from target object
    --> C:\...\src\util\GeneralUtil.js:1041:13
     |
1041 |         if(!obj.hasOwnProperty(key)) { continue; }
     |             ^^^^^^^^^^^^^^^^^^^^^^^
     |
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1042:9
     |
1042 |         var val=obj[key];
     |         ^^^^^^^^^^^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1042:9
     |
1042 |         var val=obj[key];
     |         ^^^^^^^^^^^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1054:9
     |
1054 |     for(var key in obj) {
     |         ^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1054:9
     |
1054 |     for(var key in obj) {
     |         ^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-prototype-builtins]: Access to Object.prototype.hasOwnProperty is not allowed from target object
    --> C:\...\src\util\GeneralUtil.js:1055:13
     |
1055 |         if(!obj.hasOwnProperty(key)) { continue; }
     |             ^^^^^^^^^^^^^^^^^^^^^^^
     |
error[no-prototype-builtins]: Access to Object.prototype.hasOwnProperty is not allowed from target object
    --> C:\...\src\util\GeneralUtil.js:1055:13
     |
1055 |         if(!obj.hasOwnProperty(key)) { continue; }
     |             ^^^^^^^^^^^^^^^^^^^^^^^
     |
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1056:9
     |
1056 |         var val     = obj[key];
     |         ^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: Move the declaration up into the correct scope
error[no-inner-declarations]: Move variable declaration to function root
    --> C:\...\src\util\GeneralUtil.js:1056:9
     |
1056 |         var val     = obj[key];
     |         ^^^^^^^^^^^^^^^^^^^^^^^
     |
     = help: Move the declaration up into the correct scope
Found 84 problems

C:\...\build\code>

bug

opened by lawrence-dol 12

Changes to LintRule
Add LintRule::lint_program(&self, context: &mut Context, program: &swc_ecmascript::ast::Program) in favor of LintRule::lint_module - prerequisite for #366

Rules should implement Visit trait directly on the struct implementing LintRule instead of creating additional visitor for each rule
opened by bartlomieju 12
feat: proof of concept for plugin system
Ref #159

[x] add deno_core as dev dependency

[ ] accept some flag (--plugins) that collects path to JS files containing JS visitors

[x] create JsRuntime and execute visitor code in global scope (this is hacky, but way simpler to implement than using modules)

[x] obtain JSON AST from Rust

[ ] load provided plugin files

[ ] for each loaded plugin file run its visitor and collect diagnostics (let's say that we expect plugin files to have default export which is a subclass of Visitor)

[x] return diagnostics to Rust for further processing
opened by littledivy 11
Question: Why does deno not use `get_recommended_rules`?

deno_lint provides get_recommended_rules function as public, so that users of deno_lint can get information about available implemented rules. However, this function seems not to be used by deno, and deno has its own get_rules function.

Is this a temporary measure until deno_lint implements all of the recommended rules? In other words, once deno_lint has the all recommended rules implemented, deno will use get_recommended_rules instead of get_rules? I'm curious about the reason why deno is not using get_recommended_rules now.

opened by magurotuna 11
typescript-eslint recommended rules
Tracking issues for recommended rules of typescript-eslint

https://github.com/typescript-eslint/typescript-eslint/blob/v3.1.0/packages/eslint-plugin/src/configs/recommended.ts

[x] adjacent-overload-signatures (easy)

[x] ban-ts-comment

[x] ban-types

[x] explicit-module-boundary-types (easy)

[x] no-array-constructor

[x] no-empty-function (needs to be fixed, false positives for constructors)

[x] no-empty-interface

[x] no-explicit-any

[x] no-extra-non-null-assertion

[x] no-extra-semi (easy)

[x] no-inferrable-types (easy)

[x] no-misused-new

[x] no-namespace

[x] no-non-null-asserted-optional-chain

[x] no-non-null-assertion

[x] no-this-alias

[x] no-unused-vars (hard, needs scope analysis)

[x] ~~no-var-requires~~

[x] prefer-as-const

[x] prefer-namespace-keyword

[x] triple-slash-reference

epic
opened by bartlomieju 11
Unused import triggers no-unused-vars rule
Lint Name

no-unused-vars

Code Snippet

import { anything } from './file.ts';

Expected Result

Warning related to unused import

Actual Result

no-unused-vars warning

Additional Info

To be specific, renaming... certainly works, but isn't as simple as the warning suggests

Version

deno 1.11.0 (release, x86_64-unknown-linux-gnu) v8 9.1.269.35 typescript 4.3.2
bug
opened by somebody1234 10
Add new lint that bans `private` modifiers

TypeScript 4.3 supports private class fields with #, aligning with the ECMAScript proposal. The hash prefix (#) will work in both TypeScript and JavaScript, while private modifier doesn't once transpiled to JS - the private keyword is finally eliminated while being converted to JS. playground So basically we should prefer # to private for more strictness unless there is any particular reason. It would be great if deno_lint has a new lint rule to help migrate from private to #.

One concern is that this new rule is kind of controversial if it's enabled by default. Perhaps we should implement it without turning on by default at first to see if it works well for the internals of Deno.

opened by magurotuna 10
Feature Request: Maximum Cyclomatic Complexity
Summary

In order to improve code readability and reduce the likelihood of (practically) untestable and/or unreachable conditions, it would be nice to enforce a maximum upper bound on the Cyclomatic Complexity of any given function

From the equivalent ESLint rule:

This rule is aimed at reducing code complexity by capping the amount of cyclomatic complexity allowed in a program. As such, it will warn when the cyclomatic complexity crosses the configured threshold (default is 20)

Details

Suggested rule name: complexity or cyclomatic-complexity

Suggested default value: 20 (same as ESLint)
opened by wgehring-ml 0
prefer-primordials: add check for `Promise.all`

https://github.com/denoland/deno/pull/16326

This PR has introduced SafePromiseAll which is a safe version of Promise.all. It would be nice if prefer-primordials could check for this.

Also, in my opinion, it would be much better if PromisePrototypeThen (and other similar stuff) could be checked by the linter. My rudimentary idea is that we have the linter check for all .then(...) and warn them. Obviously this approach would produce lots of false positives, i.e. the linter would warn the call .then(...) even if this then method is not for Promise. That said, I believe false positives are much better than false negatives in this case. When false positives occur we can suppress them, saying "hey linter, trust me, this is a false positive." However, when it comes to false negatives, we can never notice that there is problematic code that's prone to pollution from malicious users.

opened by magurotuna 0
Lint for unversioned npm specifiers

Doing something like import chalk from "npm:chalk" is nice for quick hacking, but shouldn't be used in real apps. I think maybe this lint might be best done in the cli though because it involves resolving import maps in some cases.
suggestion

opened by dsherret 0
Feature Request: Syntax for ignore-directives should allow for an explanation
Summary

When a programmer bypasses a configured linting rule, they should be able to document why they made an exception. This can improve code clarity, and should encourage future programmers only to ignore a rule when there's a clear reason for doing so.

Syntax

It could use a dash preceded by a space:

// deno-lint-ignore no-explicit-any - We don't want to restrict the value's type type Dict = Record<string, any>;

Two dashes might be clearer, and easier to distinguish from rules when parsing.

// deno-lint-ignore no-explicit-any -- We don't want to restrict the value's type type Dict = Record<string, any>;
opened by binyamin 1
Suggestion: syntactically deny direct `eval`

Direct eval occurs when the global eval function is directly called as eval(...); that is reassigning it, obtaining it from the result of a larger expression such as a ternary operation, or used as a property (a.eval(s)), may not invoke direct eval. (I don't know whether ((eval)(s)) is direct eval.)

See my comment here: https://github.com/denoland/deno/commit/2d3df94d6164b945e0184043b00078fe43229f7a

Furthermore, see discussion here: https://github.com/denoland/deno_lint/pull/1063#issuecomment-1207337749

Denying the expression eval(s) for Deno's internal code is all that should be necessary to prevent the bug, especially as it sounds quite unreasonable that it couldn't be renamed, or that eval would be assigned something other than the original eval.

opened by Phosra 0
Rule suggestion: Require locks for remote imports

Deno already has support for integrity checking via lock files. It would be nice to be able to enforce that these are always used for remote imports that might have changed.

opened by stabai 0