eslint updates

README.md

@@ -14,7 +14,7 @@ This document is not intended to:
 * Give advice on design patterns and project architecture
 * Guide the reader in learning JavaScript
 
-[ESLint Config for the Nerdery JavaScript Standards](https://github.com/thenerdery/javascript-standards/linters)
+[ESLint Config for the Nerdery JavaScript Standards](https://github.com/thenerdery/javascript-standards/tree/master/linters)
 
 ## Table of Contents
 

linters/tslint.json

@@ -0,0 +1,161 @@
+{
+  "extends": ["tslint-eslint-rules"],
+  "rules": {
+
+    // RECOMMENDATIONS
+
+    "interface-name": [true, "never-prefix"],     // Require interface names to not have an “I” prefix
+    "deprecation": true,                          // Warn when deprecated APIs are used
+    "member-ordering": [                          // Enforce member ordering
+      true,
+      {
+        "order": "fields-first"
+      }
+    ],
+
+    // MODULES <https://github.com/thenerdery/javascript-standards#modules>
+
+    "no-duplicate-imports": true,                 // Disallow duplicate imports
+
+    // ARROW FUNCTIONS <https://github.com/thenerdery/javascript-standards#arrow-functions>
+
+    "prefer-arrow-callback": 2,                   // Require arrow functions as callbacks
+    "arrow-spacing": [2, {                        // Require space before/after arrows
+      "before": true,
+      "after": true
+    }],
+
+    // VARIABLES <https://github.com/thenerdery/javascript-standards#variables>
+
+    "variable-name": [                            // Check variable names for various errors
+      true,
+      "ban-keywords",
+      "check-format",
+      "allow-leading-underscore",
+      "allow-pascal-case"
+    ],
+    "one-variable-per-declaration": true,         // Disallow multiple variable definitions in the same declaration statement
+    "no-duplicate-variable": [                    // Disallow duplicate variable declarations in the same block scope, including parameters
+      true,
+      "check-parameters"
+    ],
+    "no-unused-expression": true,                 // Disallow unused expression statements
+    "no-shadowed-variable": true,                 // Disallow shadowing variable declarations
+    "no-unused-variable": true,                   // Disallow unused imports, variables, functions and private class members
+    "no-use-before-declare": true,                // Disallow usage of variables before their declaration
+    "no-var-keyword": true,                       // Disallow usage of the var keyword
+    "prefer-const": true,                         // Require const when not reassigned
+
+    // OBJECTS <https://github.com/thenerdery/javascript-standards#objects>
+
+    "object-literal-shorthand": true,             // Enforce use of ES6 object literal shorthand
+
+    // TYPES <https://github.com/thenerdery/javascript-standards#types>
+
+    "typedef": [                                  // Require type definitions to exist
+      true,
+      "parameter",
+      "property-declaration"
+    ],
+    "typedef-whitespace": [                       // Enforce one space after type information
+      true,
+      {
+          "call-signature": "nospace",
+          "index-signature": "nospace",
+          "parameter": "nospace",
+          "property-declaration": "nospace",
+          "variable-declaration": "nospace"
+      }
+    ],
+    "no-any": true,                               // Disallow usage of any as a type declaration
+    "ban-types": [                                // Disallow use of Object and String types
+      true,
+      ["Object"],
+      ["Boolean"],
+      ["String"],
+      ["Function"]
+    ],
+    "no-extra-boolean-cast": true,                // Prevent unnecessary boolean cast
+    "no-invalid-regexp": true,                    // Disallow invalid regular expression strings in the RegExp constructor
+    "no-construct": true,                         // Disallow String/Number/Boolean constructors
+    "radix": true,                                // Require the radix parameter to be specified when calling parseInt
+    "no-bitwise": true,                           // Disallow bitwise operators
+
+    // STRINGS <https://github.com/thenerdery/javascript-standards#strings>
+
+    "no-eval": true,                              // Disallow eval function invocations
+    "quotemark": [true, "single", "jsx-double"],  // Prefer single quotes for strings
+
+    // BLOCKS <https://github.com/thenerdery/javascript-standards#blocks>
+
+    "forin": true,                                // Require a for ... in statement to be filtered with an if statement
+    "curly": [true, "ignore-same-line"],          // Enforce braces for if/for/do/while statements
+
+    // COMPARISON <https://github.com/thenerdery/javascript-standards#comparison>
+
+    "no-duplicate-switch-case": true,             // Prevent duplicate cases in switch statements
+    "no-conditional-assignment": true,            // Disallow assignment within conditionals
+    "cyclomatic-complexity": [true, 8],         // Enforce a threshold of cyclomatic complexity
+    "no-switch-case-fall-through": true,          // Disallow falling through case statements
+    "triple-equals": [true, "allow-null-check"],  // Require === and !==, allow null check
+
+    // WHITESPACE <https://github.com/thenerdery/javascript-standards#whitespace>
+
+    "no-multi-spaces": [true],                    // Disallow multiple spaces
+    "whitespace": [                               // Enforce whitespace style conventions
+      true,
+      "check-branch",
+      "check-decl",
+      "check-module",
+      "check-operator",
+      "check-separator",
+      "check-rest-spread",
+      "check-type",
+      "check-typecast",
+      "check-type-operator",
+      "check-preblock"
+    ],
+    "object-curly-spacing": [2, "always"],        // Require spaces inside object curly braces
+    "indent": [true, "spaces", 4],                // Enforce 4 spaces
+    "no-irregular-whitespace": true,              // Disallow irregular whitespace
+    "no-trailing-whitespace": true,               // Disallow trailing whitespace at the end of a line
+    "array-bracket-spacing": [2, "never"],        // Disallow spaces inside of brackets
+    "eofline": true,                              // Require file to end with a newline
+    "max-line-length": [                          // Disallow lines over 100 characters
+      true,
+      {
+        "limit": 100,
+        "ignore-pattern": "^import "
+      }
+    ],
+
+    // SEMICOLONS <https://github.com/thenerdery/javascript-standards#semicolons>
+
+    "semicolon": [true, "always"],                // Require semicolons
+    "no-extra-semi": true,                        // Disallow extra semicolons
+
+    // COMMENTS <https://github.com/thenerdery/javascript-standards#comments>
+
+    "jsdoc-format": true,                         // Enforce basic format rules for JSDoc comments
+    "valid-jsdoc": [2, {                          // Require docblocks match params/return type
+      "requireParamDescription": false,
+      "requireReturnDescription": false,
+      "requireReturn": false
+    }],
+    "comment-format": [                           // Require a space before comment
+      true,
+      "check-space"
+    ],
+
+    // COMMAS <https://github.com/thenerdery/javascript-standards#commas>
+
+    "trailing-comma": [                           // Require trailing commas
+      true,
+      {
+        "multiline": "always",
+        "singleline": "never"
+      }
+    ]
+
+  }
+}

packages/eslint-config-nerdery-base/.eslintrc.js

@@ -0,0 +1,61 @@
+module.exports = {
+  rules: {
+    'max-params': [2, 5], // Disallow more than 5 parameters
+    'no-implicit-coercion': 2, // Disallow type conversion with shorter notations
+    'class-methods-use-this': 0, // Allow class instance methods that don't use `this` to prevent unnecessary refactors
+    'arrow-body-style': 0, // Disabled. Just because you *can* make something a one-liner, doesn't mean you should.
+    'prefer-destructuring': ['error', { // Only prefer destructuring for `const { a } = obj;` (instead of `const a = obj.a`). Arrays and reassignments are left up to developer discretion.
+      VariableDeclarator: {
+        array: false,
+        object: true,
+      },
+      AssignmentExpression: {
+        array: false,
+        object: false,
+      },
+    }, {
+      enforceForRenamedProperties: false,
+    }],
+    'no-continue': 0, // Allow continues. They can be used like an early return to increase readability.
+    'no-plusplus': 0, // Allow ++ and --. The rationale for using this rule is that the operators are susceptible to automatic semicolon insertion issues, but that's an unlikely problem to run into.
+    'object-curly-newline': 0, // Disabled to leave up to developer discretion
+    'vars-on-top': 0, // Disabled because vars are disallowed so this check is superfluous
+    'arrow-parens': [2, 'as-needed'], // Require parens in arrow function arguments
+    'camelcase': [2, { properties: 'always' }], // Require camelCase property names
+    'newline-per-chained-call': [2, { // Require newline per chained method call
+      ignoreChainWithDepth: 2,
+    }],
+    'spaced-comment': ['error', 'always', { // Require whitespace before comments
+      line: {
+        markers: ['/'],
+        exceptions: ['-'],
+      },
+      block: {
+        markers: ['/', '*'],
+      },
+    }],
+    curly: 2, // Require curly brace conventions
+    'dot-notation': [2, { // Require dot notation
+      allowPattern: '^[a-z]+(_[a-z]+)+$',
+    }],
+    'array-bracket-newline': 0, // Leave up to developer discretion
+    'array-element-newline': 0, // Leave up to developer discretion
+    'function-call-argument-newline': 0, // Leave up to developer discretion
+    'max-depth': [1, 4], // Warn when blocks are nested too deeply
+    'max-lines': [1, 500], // Warn when files become too long
+    'complexity': [1, 20], // Warn when code becomes too complex
+    'no-implicit-coercion': 2, // Disallow shorthand type conversions
+
+    'import/prefer-default-export': 0, // Allow single named exports to prevent unnecessary refactors
+    'import/no-default-export': 2, // Mixing default and named exports is unnecessary and can be confusing. This is a contentious topic though. Feel free to override this in your own config.
+    'import/dynamic-import-chunkname': 2, // If you're not using webpack or don't care about dynamically imported modules' filenames, feel free to disable this
+
+    // By default, we enforce sorting imports to simplify git history and make it easier when scanning for a specific import.
+    // It shouldn't cause too much trouble since it's auto-fixable, but if you find this to be more trouble than it's worth, feel free to disable these.
+    'import/order': ['error', { alphabetize: { order: 'asc' } }],
+    'sort-imports': ['error', {
+      ignoreDeclarationSort: true, // handled by import/order
+      ignoreMemberSort: false,
+    }],
+  },
+};

packages/eslint-config-nerdery-base/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "eslint-config-nerdery-base",
+  "version": "1.0.0",
+  "description": "Nerdery's base JS ESLint config",
+  "main": ".eslintrc.js",
+  "author": "Nerdery",
+  "license": "MIT"
+}