eslint-config-ash-nazg

A ruthless--though not arbitrary--degree of control for your kingdom!

One ring to rule them all!

Installation

npm i -D eslint-config-ash-nazg
install-peerdeps -d eslint-config-ash-nazg

The rules

See index.js (and node.js for ash-nazg/node rules) for the rules we explicitly include (and see sauron.js for the even stricter ash-nazg/sauron rules or great-eye (or great-eye-node) for still stricter rules though which are probably best not used).

env is set to automatically include 'shared-node-browser': true given that most environments will be Node or a browser or a polyglot Node-browser. If you really don't want this, you can override by setting 'shared-node-browser': false. Note that this setting only adds globals which are present in either Node or the browser; it won't falsely allow browser globals in a Node app or vice versa; you can use env's node: true or browser: true if you want to support Node or browser globals.

(See explicitly-unused.js for the core and extended rules we don't include (rationale for non-inclusion below).)

Main rules (also search for "error" within eslint-recommended.js of @eslint/js) for the eslint:recommended rules we inherit (though see below for our two modifications to these).
"standard" rules we inherit (though see below for our handful of modifications).
@brettz9/eslint-plugin for a number of added rules
eslint-comments/recommended
eslint-plugin-no-use-extend-native for one added rule.
eslint-plugin-no-unsanitized for two added rules.
Recommended Unicorn rules (a few items disabled and enabled as per below)
eslint-plugin-array-func for further rules

I've focused below on deviations because the original sites tend to already articulate the usefulness of the rules I have incorporated for these plugins/configs. This is for tracking design choices and not disparaging the utility of non-included rules.

Other bundled configs

The ash-nazg/node config expands upon the regular ash-nazg rules to add rules specific to Node environments. Specifically, plugin:node/recommended-module has been adopted for now along with some stylistic choices. However, if you are using more CJS exports, you can override this by adding plugin:node/recommended-script to your extends array (after ash-nazg) or, for Sauron-Node, by using sauron-node-script.

The ash-nazg/node configs also detect minimum Node from engines and set env to use the highest supported ES globals, e.g., ES2021 (and also sets node: true) as well as sets ecmaVersion.

The ash-nazg/sauron config expands upon the regular ash-nazg rules to indicate what are generally best practices but are less likely to be due to an error and may possibly also require a high (and possibly tyrannical) degree of refactoring for existing projects. See below for the rationales for inclusion.

The ash-nazg/great-eye and ash-nazg/great-eye-node configs expands on ash-nazg/sauron (and ash-nazg/sauron-node) to include rules which enforce good practices, but which are so cumbersome and may flag too much legitimate code that I personally won't regularly use them. Still, I like to track them here, including in the event that their config changes to make them less all-encompassing.

The ash-nazg/sauron-node config incorporates both ash-nazg/node and ash-nazg/sauron. It adds specific rules of its own which may be unduly strict for ash-nazg/node.

A few experimental configs have been added as well, though this might be removed or significantly modified in a future version:

+script-node.js: Applies script source type with Node; used by sauron-node-script
+script.js: Applies script source type for non-Node; used by sauron-script
sauron-node-overrides.js: sauron-node with rc and mocha
sauron-node-script-overrides.js): sauron-node-script with rc and mocha
sauron-overrides.js: sauron with rc and mocha
sauron-script.js: sauron with +script.js file
sauron-script-overrides.js: sauron-script with rc and mocha
+babel.js: Wraps a module to support equivalent babel/eslint-parser rules
mocha.js: Sets up Mocha (and chai global) on test directories (via overrides)
mocha-plus.js: Strict but reasonable rules for checking Mocha/Chai (not naming "sauron" as not bundling with Sauron)
cypress.js: Strict but reasonable rules for checking Cypress
rc.js: Config for using overrides to give Rollup and RC config files to support modules where available (and script where not)

Comparison to other "standards"

eslint-config-ash-nazg is a collection of some excellent preexisting rules other projects have created, curated with the intent of attaining productive strictness.

"standard" (config) and eslint:recommended have brought a welcome degree of pseudo-standardization for code styling and error checking.

However, they do not impose as high of a degree of control as one may find desirable to enforce common, sane styling practices, catch bad practices and hard-to-read patterns, or in some cases even catch errors.

Moreover, standard enforces a few styling rules which are contrary to regular JavaScript practice (e.g., its enforced absence of semi-colons).

ash-nazg aims to offer defaults which adhere to norms, build upon productive restrictions, and in a few cases, offer greater latitude where some constraints are unduly confining.

To see which rules from an extended config ended up enabled (we are typically inheriting "recommended" configs), see /inherited-rules/implicitly-included.

To see which rules from the extended config we disabled, see our relevant config(s) (e.g., index.js).

To see which rules from the plugin that each extended config derives from (i.e., the non-recommended rules of a plug-in), see explicitly-unused.js for ones we have consciously not used and see our relevant config(s) (e.g., index.js) for the ones we did add (alongside any recommended).

The unused folder is used to capture any (non-recommended) rules which are not explicitly either enabled or within explicitly-unused.js (as might be found during an update of our config dependencies), but it is currently, and should hopefully remain, empty, as we wish to be consciously aware of all rules from inherited projects and whether we wished to include them. As far as new rules added to recommended, we can see these within diffs of inherited-rules/implicitly-included files (built during development by npm run compare).

Rationales for inclusion of dependent plug-ins

Besides incorporating more from ESLint core, we also add rules from a few other (peer) dependencies.

eslint-plugin-compat - Though its list of browsers to support is not added by our code, it is a basic enough of a need to remind one of its need to be present (and to avoid needing to add the rule for it).
eslint-plugin-import - Besides being peer dependencies of standard, this has some additional useful rules we apply.
eslint-plugin-jsdoc - provides a number of helpful rules for catching bad or incomplete JSDoc during development. Note that we do not impose jsdoc/require-jsdoc except as a warning in ash-nazg/sauron mode, so all of the eslint-plugin-jsdoc rules should only apply when JSDoc is used. We also avoid some of eslint-plugin-jsdoc stricter checking requirements for descriptions.
eslint-plugin-markdown - Another basic use case is ensuring code snippets are linted, which is why this is expected. You may find ESLint's discussion of overrides helpful for tweaking rules for Markdown (and you may also wish to use overrides, for the eslint-plugin-jsdoc rule check-examples if you wish to lint your JSDoc examples according to different standards). In ESLint 7 it is no longer necessary to pass the file extension within the --ext flag, e.g., --ext js,md to get this to take effect when used in overrides[].files (though it does seem to be required to include md if you do use --ext).
eslint-plugin-html - One basic use case is ensuring HTML is linted, which is why this is expected. You may wish to use overrides for HTML-specific rules or enable the plugin's own rules. In ESLint 7 it is no longer necessary to pass the file extension within the --ext flag, e.g., --ext js,html to get this to take effect when used in overrides[].files (though it does seem to be required to include md if you do use --ext). (The HTML plugin lacks the Markdown plugin's ability to treat separate blocks differentially, but an issue was filed requesting support.)
eslint-plugin-promise - Besides being peer dependencies of standard, this has some additional useful rules we apply.

Deviations

Deviation from `eslint:recommended`

In comparison to eslint:recommended, ash-nazg only adds restrictions with the exceptions of:

Loosening the ESLint < 6 requirement of no-console into a mere warning and only in the stricter ash-nazg/sauron configuration. This is for the reason that console logging is too useful for debugging (and sometimes for reporting progress) to have to disable it at every turn and to distract one from actual errors.
Change no-empty so that allowEmptyCatch is true. There are enough cases where one legitimately needs to suppress errors.

Rationale for overriding `standard` rules

semi - Even if not strictly required, semi-colons are conventional in JavaScript and help denote the end of statements (as opposed to the end of a line which may continue).
indent - While it may take some getting used to, 2 spaces does allow more in one's field of vision. However, changed to use outerIIFEBody for avoiding indents with the IIFE body, as this often minimizes indent level for much or all of the whole file.
object-property-newline - Properties on the same line can be very convenient, including stacking for space to avoid max length (though without stacking the height too high).
one-var - While I normally favor enforcing conventions, this one seems to me to be of little consequence. It also prevents grouping like items together. I might favor an option to require separate lines for variable declarations, but for uninitialized ones, adding to the same line is convenient, especially for single-letter variables. I would like a rule to have declarations as close as possible to being just above any used scopes (for let and const).
object-curly-spacing - Not sure why standard switched from the default here.
quotes - avoidEscape is too reasonable to avoid ugliness; allowTemplateLiterals is useful to begin a pattern that may expend to allow other quotes or dynamic variables.
object-curly-newline - Doesn't allow let f = {foo () { dosomething(); }};
lines-between-class-members - Don't feel any need for it

Rationale for changing required rules' configuration away from ESLint defaults

While these are not part of standard or eslint-recommended, I've noted here why we have deviated from the defaults set by ESLint for those applying the rule.

array-bracket-newline - Switched to "consistent" over "always" as sometimes nice to be a little condensed, especially when representing HTML as JSON within Jamilih (or JsonML) templates.
function-paren-newline - The default multiline can get too long whereas "consistent" can be clean and short.
multiline-ternary - Inline ternary can be very readable when not spanning lines
no-empty - Empty catches occur frequently enough to justify allowEmptyCatch
no-mixed-requires - Grouping is more organized, while calls are compellingly convenient
no-warning-comments - As per great-eye discussion of this rule, to-dos can be useful, but we nevertheless include the rule with terms set to fixme and xxx so we reject these other forms of todo. To also reject todo, see great-eye.
no-restricted-globals - Use example defaults for event (and fdescribe) as convenient
no-restricted-properties - Use example default of restricting __defineGetter__ in favor of Object.defineProperty as convenient
no-restricted-syntax - Set to eliminate any use of instanceof (as it is not cross-frame safe, except if using Symbol.hasInstance)
no-shadow - It is better practice not to confuse by using globals! I didn't feel the examples for allowing necessitated their use. I added "parent", "top", "open", "close", "stop", "blur", "status", "name", "closed", and "start" to allow as frequent local variables technically shadowing globals (start for QUnit env).
object-shorthand - Enabling avoidExplicitReturnArrows as methods without this that this rule grabs (which have their own meaning with arrow functions) are more succinctly expressed in shorthand, and shorthand also conduces better to events where this refers to the element (unless one needs the outer scope this). The option avoidExplicitReturnArrows does not avoid if the functions have this (though this isn't currently documented); this is probably good, though use of this may signal an error if within a method
prefer-destructuring - Did not set array to true due to its problems with direct access of large numbers (requiring many commas) and non-iterable ‘array-like’ objects.
quote-props - Changed to "as-needed" as properties more verbose and uglier with quoting
radix - We're only dealing with ES5+ environments, so the radix is redundant for base 10.
import/order - Enforcing "builtin", "external", "internal" and then ["parent", "sibling", "index"] in any order as these may be project-specific.
import/no-unresolved - fs/promises should be allowed by default as a Node module. @uce/reactive is just a virtual package (as used by uce-template.

Rationale for not including some rules

The following rules are not included within eslint:recommended or standard, nor have we chosen to include them in any of the ash-nazg rules.

Note: italicized items refer to features I might enable if the described option could become available (or upon further review). I might also tweak some standard rules further which I have not had time to examine (but it would probably be toward the stricter rather than looser as I have been happy with it thus far).

array-element-newline - While the "consistent" option would be nice, it doesn't work well to keep up with a max width and the desire to avoid excessive height [\n a, b, \n c, d\n]
arrow-body-style - With as-needed and requireReturnForObjectLiteral, this seems reasonable, but too often in debugging, one needs to add brackets to do any logging.
func-names - Too prohibitive, though if applied to methods only, it may be useful (though with object shorthand, less necessary)
func-style - Declarations are simpler so appealing also. If enabling, would also want allowArrowFunctions.
id-blacklist - Can be helpful but a little tyrannical
id-length - Can be helpful (especially a minimum) but a little tyrannical
id-match - Too project-specific
init-declarations - Nice with "always" and ignoreForLoopInit, but cumbersome and seemingly wasteful at times
line-comment-position - Too inflexible to enforce either way
lines-around-comment - Irksome to me
max-classes-per-file - A bit tyrannical
max-depth - Sounds good but tyrannical
max-lines-per-function - A bit tyrannical
max-lines - A bit tyrannical
max-params - Can be troublesome when one is forced to abide by some API
multiline-comment-style - Would be nice if allowed multiline "starred-block" OR "bare-block" given some one may wish as JSDoc-style and others not
newline-after-var - Not very flexible (deprecated)
newline-before-return - Not very flexible (deprecated)
newline-per-chained-call - Not flexible in practice
no-continue - Can be convenient
no-inline-comments - Can be faster and more succint
no-invalid-this - Sounds good but not useful for element event handlers/jQuery
no-multi-assign - Sounds good, but can be burdensome
no-negated-condition - Is generally simpler, but it can be annoying if one wishes to get a much smaller condition body visible at the top.
no-nested-ternary - Nested ternaries can be helpful to avoid clutter of duplicated assignment code
no-param-reassign - Can be helpful, but not convenient, including when making defaults against more than undefined (e.g., null)
no-restricted-imports - Project-specific
no-restricted-modules - Project-specific
no-ternary - Not useful
no-undefined - undefined is ok for ES6 modules and strict code, so using no-global-assign and no-shadow-restricted-names instead
no-underscore-dangle - Too restrictive
no-useless-concat - Too restrictive when one has certain formatting one wishes to draw out
one-var-declaration-per-line - Sounds good, but too cumbersome for small integer or boolean inits, and the indented next lines are not as immediately clear that they belong to the declaration.
padding-line-between-statements - Might revisit
prefer-arrow-callback - Not compelling
prefer-template - Sounds good, but too cumbersome in practice
require-atomic-updates - Many false positives
sort-imports - Would be useful with "warn" if could sort by multiple/single type and sort members while avoiding alphabetical sorting across imports which seems too rigid
sort-keys - Too cumbersome
sort-vars - Too cumbersome

Rationale for disabled import rules

import/no-restricted-paths - Project-specific
import/no-internal-modules - Useful but have to specify, so project-specific
import/no-import-module-exports - Seems redundant for normal CJS
import/no-cycle - Don't see a problem with cyclic imports in ESM
import/no-nodejs-modules - Useful for some projects, but not all including even client-side (though does offer allow option)
import/no-relative-packages - Not needed for general environments
import/exports-last - Has some reason for being, but nicer to see with declaration that the object is being exported. To find all, just search for "export"
import/no-namespace - While can be more efficient to import only what one needs, having a namespace can also avoid confusion.
import/prefer-default-export - Could even be a bad practice as ugly to import with non-defaults added later
import/no-default-export - Has some basis, but defaults are admittedly convenient. Let's not be so opinionated.
import/no-named-export - Could even be a bad practice as ugly to import with non-defaults added later
import/no-relative-parent-imports - Appealing in some ways, but too rigid for a broad standard
import/dynamic-import-chunkname - Might revisit for warnings, but probably too specific for a broad standard
import/max-dependencies - Too constraining
import/no-unassigned-import - Could be useful with allow option, but that would be project-specific, and unassigned imports are needed for polyfills
import/group-exports - Too rigid as with exports-last.

Rationale for disabled Node and Promise rules

no-process-exit (added by Node recommended) - has a version in Unicorn which allows in CLI apps.

node/no-missing-import - Redundant with import/no-unresolved

node/file-extension-in-import - Redundant with import/extensions and has no ignorePackages option currently.

node/prefer-promises/dns and node/prefer-promises/fs are good, but a bit early with Node 12.

node/no-restricted-import - project-specific

node/no-restricted-require - project-specific

promise/no-native is disabled as promises are essential--even, it appears, to Dark Lords.

promise/param-names can be too tyrannical in some cases.

promise/no-nesting - can be useful to nest sometimes

promise/no-promise-in-callback - May be difficult to apply (Note: Is disabled in index.js but enabled in sauron.js)

promise/no-callback-in-promise - May be difficult to apply (Note: Is disabled in index.js but enabled in sauron.js)

promise/avoid-new - Can be useful or even necessary for APIs missing Promise version (Note: Is disabled in index.js but enabled in sauron.js; could use promisify)

promise/no-return-in-finally - (Note: Is disabled in index.js but enabled in sauron.js)

promise/valid-params - (Note: Is disabled in index.js but enabled in sauron.js)

Rationale for suppressing some `eslint-plugin-jsdoc` rules

jsdoc/no-blank-blocks - Too useful to progressively build docs with blank ones
jsdoc/check-line-alignment - More desirable default not yet implemented
jsdoc/informative-docs - Too troublesome to deal with descriptions as it is
jsdoc/no-blank-block-descriptions - Bad for debugging
jsdoc/no-types - Types have utility in jsdoc unless using TypeScript
jsdoc/newline-after-description (recommended) - I can see its draw, but seems too pedantic to me for documentation.
jsdoc/no-defaults - Haven't transitioned to TypeScript
jsdoc/no-undefined-types (recommended) - I'd like something like this, but since it isn't aware of all of one's @typedefs, etc., it is too restrictive for me at this time.
jsdoc/require-description-complete-sentence seems like a good idea, as English mistakes can be jarring as with bad styling, but this didn't seem to work too well. I use jsdoc/match-description with a special value to capture a subset of this.
jsdoc/require-hyphen-before-param-description - I can see its draw, but seems too pedantic to me for documentation.
jsdoc/sort-tags - A bit oppressive (and probably a bit unstable still as a new rule); might revisit
jsdoc/no-missing-syntax - Nothing currently wish to enforce
jsdoc/no-restricted-syntax - Nothing currently wish to enforce

Rationale for disabling some `unicorn` rules

(The following are recommended rules unless otherwise noted.)

catch-error-name - It can actually be useful to use different error names to indicate what type of error may be expected.
consistent-destructuring - In practice can be cumbersome
consistent-function-scoping - Though this can be useful, and it shouldn't be difficult to manually hoist functions upward, besides taking some time to refactor, this often removes functions from a logical grouping, and may even increase bugs, as one may be tempted to move out a function whose dependency is no longer wrapped with it.
empty-brace-spaces - Easier to build on and cleaner if allowing newlines
explicit-length-check - Seems wasteful.
filename-case - Looks potentially useful with camelCase.
import-index - While understandable, seems may cause more trouble in making it harder to find references to index.
import-style - Using eslint-plugin-import instead
no-array-reduce - Though I can see some appeal to this (and reduce also suffers from not being able to short-circuit), I like it for object property accumulation, conditional array accumulation that can later be flattened, etc. It also seems superfluous to add an extra join with string concatenation.
no-array-for-each - Writing code for forEach allows later refactoring, e.g., to move out of the block.
no-await-expression-member - A bit confining for convenience for only a little gain
no-instanceof-array - Covered by our blocking of all instanceof
no-keyword-prefix - See no need.
no-lonely-if - Nested ifs can be useful to catch and ignore.
no-negated-condition - Good but cumbersome
no-nested-ternary - As with eslint's no-nested-ternary
no-null - A good idea, but besides use of null in JSON, and semantic arguments in favor (having an explicit, intentional empty value), it makes for cleaner, quicker to understand code.
no-typeof-undefined - Ok but cumbersome, especially if global situation is complicated
no-unreadable-array-destructuring - Better to use this than multiple lines
no-unused-properties - While no doubt useful, it won't catch all cases, sounds computationally expensive, and may better be done with TypeScript
no-useless-switch-case - Still useful for flagging a viable value or faciliating later expansion
no-useless-undefined - I don't like the consequence of changing array-callback-return to allowImplicit, and it can make clear that use of undefined is deliberate.
prefer-array-flat - Present in array-func
prefer-array-flat-map - Present in array-func
prefer-at - Not widely available
prefer-exponentiation - Now present in eslint core
prefer-export-from - Understandable but cumbersome when importing anyways and have to use another style
prefer-json-parse-buffer - Not recommended now and may be less performant
prefer-module - Handling by different configs instead
prefer-node-protocol - Might revisit later if practice becomes adopted
prefer-object-from-entries - Too many false positives (e.g., non-simple objects)
prefer-optional-catch-binding - Understandable rule, but extra work if refactoring to add later, and the catch binding can also force documentation of the error's purpose
prefer-prototype-methods - Sometimes a bit cumbersome
prefer-string-slice - Added to Sauron but can be cumbersome to change for old projects
prefer-string-replace-all - Good but not available yet in Node (even 14)
prefer-top-level-await - Good requires Babel currently
regex-shorthand - Was renamed to better-regex.
string-content - Don't want the trouble of requiring formatted apostrophes (not recommended anyways).
switch-case-braces - Reasonable but burdensome as may not need braces
template-indent - Although attractive, requires tooling to be reliable.
throw-new-error - Potentially confining.

Rationale for altering default on Unicorn rules

better-regex - Character classes can be arranged for readability.

Rationale for including some Unicorn rules which are disabled in `plugin:unicorn/recommended`

unicorn/custom-error-definition - Does not seem confining.
unicorn/no-unsafe-regex - Seems like something to watch for, though I may revisit if this reports too many common expressions.
unicorn/require-post-message-target-origin - Useful for common cases

Rationale for including eslint-comments rules which are not in `plugin:eslint-comments/recommended`

eslint-comments/no-unused-disable - Might be indicative of an error and inefficient in any case

Rationale for changing eslint-comments rules from default recommended

eslint-comments/disable-enable-pair - If at top, behavior is clear, and no need to reenable within doc

Rationale for not including some `eslint-comments` rules

eslint-comments/no-restricted-disable - See no need
eslint-comments/no-use - See no need

Rationale for not including some `plugin:@brettz9/es6` rules

@brettz9/arrow-parens - Covered by other rules
@brettz9/no-instanceof-array - Covered by our blocking of all instanceof
@brettz9/no-instanceof-wrapper - Covered by our blocking of all instanceof
@brettz9/prefer-for-of - I prefer array extras for easier reuse, currying, etc. than for-of
@brettz9/no-use-ignored-vars - Relies on a regex (for pseudo-privates) which can be useful

Rationale for not including some `array-func` rules

array-func/prefer-array-from - While it may benefit performance, it is more sleek to use the spread operator. Would like to know how much it impacts performance before enabling.

Rationale for not including some `sonarjs` rules

(All sonarjs rules are currently "recommended" rules as well except as noted.)

elseif-without-else - Good rationale but burdensome (not recommended)
no-nested-switch - Arbitrary and not helpful for cleaner code
no-nested-template-literals - Somewhat reasonable, but also arbitrary
max-switch-cases - Sounds too arbitrary.
no-collapsible-if - Sometimes more logically clear or made in preparation for future expansion
no-duplicate-string - Often used in test files and repeated in fairly minor instances or instances repeated but spread out within a large file
no-identical-functions - Often used in test files and repeated by fairly minor functions or functions repeated but spread out within a large file
no-small-switch - Too useful to start a pattern to which one intends to add later.
prefer-immediate-return - Can be useful for documenting even if method name should be descriptive, especially if there are different returns with subtly different results

Rationale for including eslint-plugin-jsdoc rules which are not in `plugin:jsdoc/recommended`

check-examples - If examples are present, they ought to follow one's standards, including if overrides are in place to loosen/tighten. Set to match any Markdown rules (.md extension) by default and excludes any example beginning with a backtick.
check-syntax - Following jsdoc, not Closure syntax
match-description - Cleaner to see complete sentences which its default allows.
no-bad-blocks - Useful to catch blocks likely intended as jsdoc
require-returns-check - If the return value doesn't match, there may be a problem.
require-file-overview - Don't need @file in every file.

Rationale for only including some rules within `ash-nazg/sauron`

These are good practices, but cumbersome, not as familiar to developers, prohibitive during ongoing debugging or conversion of existing projects, etc. But perhaps useful for a new project which can pay closer attention to standards without the undue burden of having to refactor lots of code (which may not all be under one's control).

class-methods-use-this - Good for new code (though even here may need disabling). May break existing APIs.
consistent-this - A good practice, but sometimes, especially with jQuery or DOM event handlers, and large functions where it can be difficult to track what a generic that is in reference to, this may be more clearly named as the object
default-case - Refactoring code to know whether to throw or silently ignore requires time.
no-implicit-globals with lexicalBindings to true - Light browser apps might now want
max-len - May require a lot of refactoring.
no-alert - No quick easy replacement yet with poor dialog support.
no-console - Useful for debugging (and sometimes for reporting progress) to have to disable it at every turn and to distract one from actual errors, even for production.
no-empty-function - Cumbersome to add comments within every no-op.
no-shadow - Can catch errors, but also some work to refactor (See also section "Rationale for changing required rules' configuration away from defaults".)
prefer-numeric-literals - Good but some work.
require-unicode-regexp - Good, but some work to fix all.
vars-on-top - Not needed for let/const, and if overriding, this is cumbersome, despite being useful
import/unambiguous - A good practice, and one which overrides can override (e.g., for polyfills or simple HTML tests), but cumbersome to label all files
promise/prefer-await-to-callbacks - Sometimes useful, but callbacks may be used within repeating events
unicorn/no-array-callback-reference - May be cumbersome though does catch potential problems
unicorn/prefer-number-properties - Good but some refactoring needed (and not always readily fixable).
jsdoc/require-returns (recommended) - Put in ash-nazg/sauron as it is more than just a consistent styling convention, and it is not impossible to follow, but a bit difficult. Added forceRequireReturn option to ensure return type considered even if void/undefined and added contexts: ['any'] so it checks virtual functions (e.g., with @implements).
jsdoc/require-jsdoc (recommended) - Imposes a heavy burden on preexisting large projects (added as "error" in great-eye.js); we have expanded its options there though to check on ClassDeclaration, ClassExpression, and MethodDefinition in addition to FunctionDeclaration. This may still FunctionExpression and ArrowFunctionExpression, and these may admittedly be used on such as exports, but until the context option discussed at https://github.com/gajus/eslint-plugin-jsdoc/issues/384 may be fixed, that may be too oppressive to impose.
jsdoc/require-param-name (recommended): Expanded this to contexts: ['any']; see description for jsdoc/require-jsdoc.
jsdoc/require-param-type (recommended): Expanded this to contexts: ['any']; see description for jsdoc/require-jsdoc.
jsdoc/require-returns-type (recommended): Expanded this to contexts: ['any']; see description for jsdoc/require-jsdoc.
jsdoc/implements-on-classes - Added with contexts: ['any']; see description for jsdoc/require-jsdoc. Better to be TypeScript-compatible.

The forceRequireReturn setting was also applied therein as it may be cumbersome to add to all returns or not favored as a requirement in all projects though it does note that a method's return was considered even if undefined.

The preferredTypes setting was enabled here as it can be cumbersome for projects to specify all child types.

Rationale for only including some rules within `ash-nazg/great-eye`

capitalized-comments - May be very prevalent; reports with commented out code
complexity - A generally good practice, but can be work to refactor, and sometimes impractical to enforce.
no-shadow with hoist: 'all' - A person should generally be able to track what they have in a function and it can be useful to reuse the variable name, but to really prevent any possible confusion, this should be set.
max-statements-per-line - Tyrannical when prohibiting single-line if (...) { continue; }; might revisit if allowed for control statements
max-statements - A bit tyrannical even if good for clear code
no-magic-numbers - Very helpful for clear code, but cumbersome, and sometimes very cumbersome.
no-plusplus - Would be nice if there were an option to allow if not combined inline with other expressions
no-warning-comments (with default value on terms option blocking "todo") - Good to catch to-dos, but better to search or parse code as a separate process rather than polluting one's ESLint warnings--some to-dos are ok to be left for the long term
import/no-unused-modules - Useful (for missingExports at least), but doesn't catch dynamic imports and reports for other deliberately non-modular scripts
jsdoc/check-alignment (recommended) - A pretty good practice, but not that important.
jsdoc/check-indentation - A pretty good practice, but that that important.
jsdoc/require-description - Though a very good practices, this is difficult for large code bases to implement and even cumbersome for new ones to have to follow for lesser parameters, so that's why they are not even in ash-nazg/sauron, though if you feel you can succeed at imposing such rigor for your hordes of developer minions, by all means, have a hand at it...
jsdoc/require-param-description (recommended) - See jsdoc/require-description.
jsdoc/require-returns-description (recommended) - See jsdoc/require-description.
jsdoc/require-property-description (recommended) - See jsdoc/require-description.
jsdoc/require-example - See jsdoc/require-description.
sonarjs/cognitive-complexity - As with complexity perhaps (though may add to sauron if demonstrates not to be too oppressive)
unicorn/numeric-separators-style - Good but may involve many changes.
unicorn/prevent-abbreviations - Very cumbersome for frequent conventions such as e for event
unicorn/prefer-set-has - Very good, but troublesome to refactor.
unicorn/prefer-object-has-own - Good but only available by polyfill

The preferredTypes setting was enabled here for integer/float as it can be cumbersome for projects to distinguish and because Promise even subclassed doesn't indicate the rejector type.

Rationale for including rules that might not seem necessary

no-implicit-globals - Included despite not applying to modules, in case overriding.
strict - Included despite not being needed for modules, in case overriding.

Rationale for not including some non-recommended eslint rules

no-return-await - As per this issue, it causes problems with stack traces and fails to flag function return as async (particularly in conjunction with require-await which effectively enforces not using async on such functions either).
prefer-object-has-own - Not yet supported in all Node
(This section is incomplete)

Deprecated rule non-inclusion

Deprecated and removed items from ESLint are also naturally not included.

Contributing

While I will admit to being opinionated, and one may need to disable some rules (or possibly add a few ones mentioned in my non-inclusion sections), feel free to file issues if you really feel there are compelling reasons for different defaults. But again, I have to add caution that ring bearers can be picky about giving up their preh-shus...

To-dos

Waiting: Add eslint-plugin-no-constructor-bind when class properties start landing
Add own rules:
Review https://github.com/dustinspecker/awesome-eslint#practices
See if https://github.com/sarbbottam/eslint-find-rules may eliminate need for our comparison code
Rule for no functions with this (to use class)? Might adapt https://github.com/matijs/eslint-plugin-this?
To consider:
See also eslint-plugin-privileges for plugins/config to add for security/transparency
Make plugins/tool config/toolkit?
- https://github.com/not-an-aardvark/eslint-plugin-eslint-plugin
- https://github.com/j-f1/eslint-docs
- https://github.com/jfmengels/eslint-rule-documentation
- https://github.com/sarbbottam/eslint-find-rules
- https://github.com/pimlie/eslint-multiplexer
- https://github.com/wagerfield/eslint-index
- https://github.com/nickdeis/eslint-plugin-notice
- https://github.com/eslint/generator-eslint (global install of yo also)
- Note eslint --print-config file for getting at applied config for a file