L1.7.2: evaluations within JSX. ESLint checks.

.eslintrc.json

@@ -0,0 +1,474 @@
+{
+  "env": {
+    "browser": true,
+    "node": true,
+    "es6": true
+  },
+  "globals": {
+    "React": false,
+    "ReactDOM": false
+  },
+  "parser": "babel-eslint",
+  "plugins": [
+    "react"
+  ],
+  "ecmaFeatures": {
+    "arrowFunctions": true,
+    "binaryLiterals": true,
+    "blockBindings": true,
+    "classes": true,
+    "defaultParams": true,
+    "destructuring": true,
+    "forOf": true,
+    "generators": true,
+    "modules": true,
+    "objectLiteralComputedProperties": true,
+    "objectLiteralDuplicateProperties": true,
+    "objectLiteralShorthandMethods": true,
+    "objectLiteralShorthandProperties": true,
+    "octalLiterals": true,
+    "regexUFlag": true,
+    "regexYFlag": true,
+    "spread": true,
+    "superInFunctions": true,
+    "templateStrings": true,
+    "unicodeCodePointEscapes": true,
+    "globalReturn": true,
+    "jsx": true
+  },
+  "rules": {
+    //
+    //Possible Errors
+    //
+    // The following rules point out areas where you might have made mistakes.
+    //
+    "comma-dangle": 2,
+    // disallow or enforce trailing commas
+    "no-cond-assign": 2,
+    // disallow assignment in conditional expressions
+    "no-console": 1,
+    // disallow use of console (off by default in the node environment)
+    "no-constant-condition": 2,
+    // disallow use of constant expressions in conditions
+    "no-control-regex": 2,
+    // disallow control characters in regular expressions
+    "no-debugger": 2,
+    // disallow use of debugger
+    "no-dupe-args": 2,
+    // disallow duplicate arguments in functions
+    "no-dupe-keys": 2,
+    // disallow duplicate keys when creating object literals
+    "no-duplicate-case": 2,
+    // disallow a duplicate case label.
+    "no-empty": 2,
+    // disallow empty statements
+    "no-empty-character-class": 2,
+    // disallow the use of empty character classes in regular expressions
+    "no-ex-assign": 2,
+    // disallow assigning to the exception in a catch block
+    "no-extra-boolean-cast": 2,
+    // disallow double-negation boolean casts in a boolean context
+    "no-extra-parens": 1, // disallow unnecessary parentheses (off by default)
+    "no-extra-semi": 2, // disallow unnecessary semicolons
+    "no-func-assign": 2,
+    // disallow overwriting functions written as function declarations
+    "no-inner-declarations": 2,
+    // disallow function or variable declarations in nested blocks
+    "no-invalid-regexp": 2,
+    // disallow invalid regular expression strings in the RegExp constructor
+    "no-irregular-whitespace": 2,
+    // disallow irregular whitespace outside of strings and comments
+    "no-negated-in-lhs": 2,
+    // disallow negation of the left operand of an in expression
+    "no-obj-calls": 2,
+    // disallow the use of object properties of the global object (Math and JSON) as functions
+    "no-regex-spaces": 2,
+    // disallow multiple spaces in a regular expression literal
+    "quote-props": 2,
+    // disallow reserved words being used as object literal keys (off by default)
+    "no-sparse-arrays": 2,
+    // disallow sparse arrays
+    "no-unreachable": 2,
+    // disallow unreachable statements after a return,throw, continue, or break statement
+    "use-isnan": 2,
+    // disallow comparisons with the value NaN
+    "valid-jsdoc": 2,
+    // Ensure JSDoc comments are valid (off by default)
+    "valid-typeof": 2,
+    // Ensure that the results of typeof are compared against a valid string
+    //
+    // Best Practices
+    //
+    // These are rules designed to prevent you from making mistakes.
+    // They either prescribe a better way of doing something or help you avoid footguns.
+    //
+    "block-scoped-var": 0,
+    // treat var statements as if they were block scoped (off by default). 0: deep destructuring is not compatible https://github.com/eslint/eslint/issues/1863
+    "complexity": 0,
+    // specify the maximum cyclomatic complexity allowed in a program (off by default)
+    "consistent-return": 2,
+    // require return statements to either always or never specify values
+    "curly": 2,
+    // specify curly brace conventions for all control statements
+    "default-case": 2,
+    // require default case in switch statements (off by default)
+    "dot-notation": 2,
+    // encourages use of dot notation whenever possible
+    "eqeqeq": 2,
+    // require the use of === and !==
+    "guard-for-in": 2,
+    // make sure for-in loops have an if statement (off by default)
+    "no-alert": 2,
+    // disallow the use of alert, confirm, and prompt
+    "no-caller": 2,
+    // disallow use of arguments.caller or arguments.callee
+    "no-div-regex": 2,
+    // disallow division operators explicitly at beginning of regular expression (off by default)
+    "no-else-return": 2,
+    // disallow else after a return in an if (off by default)
+    "no-eq-null": 2,
+    // disallow comparisons to null without a type-checking operator (off by default)
+    "no-eval": 2,
+    // disallow use of eval()
+    "no-extend-native": 2,
+    // disallow adding to native types
+    "no-extra-bind": 2,
+    // disallow unnecessary function binding
+    "no-fallthrough": 2,
+    // disallow fallthrough of case statements
+    "no-floating-decimal": 2,
+    // disallow the use of leading or trailing decimal points in numeric literals (off by default)
+    "no-implied-eval": 2,
+    // disallow use of eval()-like methods
+    "no-iterator": 2,
+    // disallow usage of __iterator__ property
+    "no-labels": 2,
+    // disallow use of labeled statements
+    "no-lone-blocks": 2,
+    // disallow unnecessary nested blocks
+    "no-loop-func": 2,
+    // disallow creation of functions within loops
+    "no-multi-spaces": 2,
+    // disallow use of multiple spaces
+    "no-multi-str": 2,
+    // disallow use of multiline strings
+    "no-native-reassign": 2,
+    // disallow reassignments of native objects
+    "no-new": 2,
+    // disallow use of new operator when not part of the assignment or comparison
+    "no-new-func": 2,
+    // disallow use of new operator for Function object
+    "no-new-wrappers": 2,
+    // disallows creating new instances of String,Number, and Boolean
+    "no-octal": 2, // disallow use of octal literals
+    "no-octal-escape": 2,    // disallow use of octal escape sequences in string literals, such as var foo = "Copyright \251";
+    "no-param-reassign": 2,
+    // disallow reassignment of function parameters (off by default)
+    "no-process-env": 2,
+    // disallow use of process.env (off by default)
+    "no-proto": 2,
+    // disallow usage of __proto__ property
+    "no-redeclare": 2,
+    // disallow declaring the same variable more then once
+    "no-return-assign": 2,
+    // disallow use of assignment in return statement
+    "no-script-url": 2,
+    // disallow use of javascript: urls.
+    "no-self-compare": 2,
+    // disallow comparisons where both sides are exactly the same (off by default)
+    "no-sequences": 2,
+    // disallow use of comma operator
+    "no-throw-literal": 2,
+    // restrict what can be thrown as an exception (off by default)
+    "no-unused-expressions": 2,
+    // disallow usage of expressions in statement position
+    "no-void": 2,
+    // disallow use of void operator (off by default)
+    "no-warning-comments": [
+      0,
+      {
+        "terms": [
+          "todo",
+          "fixme"
+        ],
+        "location": "start"
+      }
+    ],
+    // disallow usage of configurable warning terms in comments": 2, // e.g. TODO or FIXME (off by default)
+    "no-with": 2,
+    // disallow use of the with statement
+    "radix": 2,
+    // require use of the second argument for parseInt() (off by default)
+    "vars-on-top": 2,
+    // requires to declare all vars on top of their containing scope (off by default)
+    "wrap-iife": 2,
+    // require immediate function invocation to be wrapped in parentheses (off by default)
+    "yoda": 2,
+    // require or disallow Yoda conditions
+    //
+    // Strict Mode
+    //
+    // These rules relate to using strict mode.
+    //
+    "strict": 0,
+    // controls location of Use Strict Directives. 0: required by `babel-eslint`
+    //
+    // Variables
+    //
+    // These rules have to do with variable declarations.
+    //
+    "no-catch-shadow": 2,
+    // disallow the catch clause parameter name being the same as a variable in the outer scope (off by default in the node environment)
+    "no-delete-var": 2,
+    // disallow deletion of variables
+    "no-label-var": 2,
+    // disallow labels that share a name with a variable
+    "no-shadow": 2,
+    // disallow declaration of variables already declared in the outer scope
+    "no-shadow-restricted-names": 2,
+    // disallow shadowing of names such as arguments
+    "no-undef": 2,
+    // disallow use of undeclared variables unless mentioned in a /*global */ block
+    "no-undef-init": 2,
+    // disallow use of undefined when initializing variables
+    "no-undefined": 2,
+    // disallow use of undefined variable (off by default)
+    "no-unused-vars": 2,
+    // disallow declaration of variables that are not used in the code
+    "no-use-before-define": 2,
+    // disallow use of variables before they are defined
+    //
+    //Stylistic Issues
+    //
+    // These rules are purely matters of style and are quite subjective.
+    //
+    "indent": [
+      1,
+      2
+    ],
+    // this option sets a specific tab width for your code (off by default)
+    "brace-style": 1,
+    // enforce one true brace style (off by default)
+    "camelcase": 1,
+    // require camel case names
+    "comma-spacing": [
+      1,
+      {
+        "before": false,
+        "after": true
+      }
+    ],
+    // enforce spacing before and after comma
+    "comma-style": [
+      1,
+      "last"
+    ],
+    // enforce one true comma style (off by default)
+    "consistent-this": [
+      1,
+      "_this"
+    ],
+    // enforces consistent naming when capturing the current execution context (off by default)
+    "eol-last": 1,
+    // enforce newline at the end of file, with no multiple empty lines
+    "func-names": 0,
+    // require function expressions to have a name (off by default)
+    "func-style": 0,
+    // enforces use of function declarations or expressions (off by default)
+    "key-spacing": [
+      1,
+      {
+        "beforeColon": false,
+        "afterColon": true
+      }
+    ],
+    // enforces spacing between keys and values in object literal properties
+    "max-nested-callbacks": [1, 3],
+    // specify the maximum depth callbacks can be nested (off by default)
+    "new-cap": [1, { "newIsCap": true, "capIsNew": false }
+    ],
+    // require a capital letter for constructors
+    "new-parens": 1,
+    // disallow the omission of parentheses when invoking a constructor with no arguments
+    "newline-after-var": 0,
+    // allow/disallow an empty newline after var statement (off by default)
+    "no-array-constructor": 1,
+    // disallow use of the Array constructor
+    "no-inline-comments": 1,
+    // disallow comments inline after code (off by default)
+    "no-lonely-if": 1,
+    // disallow if as the only statement in an else block (off by default)
+    "no-mixed-spaces-and-tabs": 1,
+    // disallow mixed spaces and tabs for indentation
+    "no-multiple-empty-lines": [
+      1,
+      {
+        "max": 2
+      }
+    ],
+    // disallow multiple empty lines (off by default)
+    "no-nested-ternary": 1,
+    // disallow nested ternary expressions (off by default)
+    "no-new-object": 1,
+    // disallow use of the Object constructor
+    "no-spaced-func": 1,
+    // disallow space between function identifier and application
+    "no-ternary": 0,
+    // disallow the use of ternary operators (off by default)
+    "no-trailing-spaces": 1,
+    // disallow trailing whitespace at the end of lines
+    "no-underscore-dangle": 1,
+    // disallow dangling underscores in identifiers
+    "no-extra-parens": 0,  // disallow wrapping of non-IIFE statements in parens
+    "one-var": [
+      1,
+      "never"
+    ],
+    // allow just one var statement per function (off by default)
+    "operator-assignment": [
+      1,
+      "never"
+    ],
+    // require assignment operator shorthand where possible or prohibit it entirely (off by default)
+    "padded-blocks": [
+      1,
+      "never"
+    ],
+    // enforce padding within blocks (off by default)
+    "quote-props": [
+      1,
+      "as-needed"
+    ],
+    // require quotes around object literal property names (off by default)
+    "quotes": [
+      1,
+      "single"
+    ],
+    // specify whether double or single quotes should be used
+    "semi": [
+      1,
+      "always"
+    ],
+    // require or disallow use of semicolons instead of ASI
+    "semi-spacing": [
+      1,
+      {
+        "before": false,
+        "after": true
+      }
+    ],
+    // enforce spacing before and after semicolons
+    "sort-vars": 0,
+    // sort variables within the same declaration block (off by default)
+    "keyword-spacing": ["error", { "before": true, "after": true }], // require a space after certain keywords (off by default)
+    "space-before-blocks": [
+      1,
+      "always"
+    ],
+    // require or disallow space before blocks (off by default)
+    "space-before-function-paren": [
+      1,
+      {
+        "anonymous": "always",
+        "named": "never"
+      }
+    ],
+    // require or disallow space before function opening parenthesis (off by default)
+    "object-curly-spacing": 1,
+    "array-bracket-spacing": 1,
+    "computed-property-spacing": 1,
+    // require or disallow spaces inside brackets (off by default)
+    "space-in-parens": [
+      1,
+      "never"
+    ],
+    // require or disallow spaces inside parentheses (off by default)
+    "space-infix-ops": ["error", {"int32Hint": false}],
+    // require spaces around operators
+    "space-unary-ops": [
+      1,
+      {
+        "words": true,
+        "nonwords": false
+      }
+    ],
+    // Require or disallow spaces before/after unary operators (words on by default, nonwords off by default)
+    "spaced-comment": [1, "always"],
+    // require or disallow a space immediately following the // in a line comment (off by default)
+    "wrap-regex": 0,
+    // require regex literals to be wrapped in parentheses (off by default)
+    //
+    // ECMAScript 6
+    //
+    // These rules are only relevant to ES6 environments and are off by default.
+    //
+    "no-var": 2,
+    // require let or const instead of var (off by default)
+    "generator-star-spacing": [
+      2,
+      "before"
+    ],
+    // enforce the spacing around the * in generator functions (off by default)
+    //
+    // Legacy
+    //
+    // The following rules are included for compatibility with JSHint and JSLint.
+    // While the names of the rules may not match up with the JSHint/JSLint counterpart,
+    // the functionality is the same.
+    //
+    "max-depth": [
+      2,
+      3
+    ],
+    // specify the maximum depth that blocks can be nested (off by default)
+    "max-len": [
+      2,
+      100,
+      2
+    ],
+    // specify the maximum length of a line in your program (off by default)
+    "max-params": [
+      2,
+      5
+    ],
+    // limits the number of parameters that can be used in the function declaration. (off by default)
+    "max-statements": 0,
+    // specify the maximum number of statement allowed in a function (off by default)
+    "no-bitwise": 0,
+    // disallow use of bitwise operators (off by default)
+    "no-plusplus": 2,
+    // disallow use of unary operators, ++ and -- (off by default)
+    //
+    // eslint-plugin-react
+    //
+    // React specific linting rules for ESLint
+    //
+    "react/display-name": 0,
+    // Prevent missing displayName in a React component definition
+    //"react/jsx-quotes": [ 2, "double", "avoid-escape"],
+    // Enforce quote style for JSX attributes
+    "react/jsx-no-undef": 2,
+    // Disallow undeclared variables in JSX
+    "react/jsx-sort-props": 0,
+    // Enforce props alphabetical sorting
+    "react/jsx-uses-react": 2,
+    // Prevent React to be incorrectly marked as unused
+    "react/jsx-uses-vars": 2,
+    // Prevent variables used in JSX to be incorrectly marked as unused
+    "react/no-did-mount-set-state": 2,
+    // Prevent usage of setState in componentDidMount
+    "react/no-did-update-set-state": 2,
+    // Prevent usage of setState in componentDidUpdate
+    "react/no-multi-comp": 0,
+    // Prevent multiple component definition per file
+    "react/no-unknown-property": 2,
+    // Prevent usage of unknown DOM property
+    "react/prop-types": 2,
+    // Prevent missing props validation in a React component definition
+    "react/react-in-jsx-scope": 2,
+    // Prevent missing React when using JSX
+    "react/self-closing-comp": 2,
+    // Prevent extra closing tags for components without children
+    "react/jsx-wrap-multilines": 2 // Prevent missing parentheses around multilines JSX
+  }
+}

package.json

@@ -1,13 +1,16 @@
 {
   "dependencies": {
+    "eslint": "^3.10.2",
     "react": "^15.4.1",
     "react-dom": "^15.4.1"
   },
   "devDependencies": {
     "babel-cli": "^6.18.0",
+    "babel-eslint": "^7.1.1",
     "babel-preset-react": "^6.16.0",
     "babel-preset-stage-0": "^6.16.0",
-    "chokidar": "^1.6.1"
+    "chokidar": "^1.6.1",
+    "eslint-plugin-react": "^6.7.1"
   },
   "scripts": {
     "build": "babel src -d lib --preset react -w"

src/components.js

@@ -1,6 +1,18 @@
 class StoryBox extends React.Component {
   render() {
-    return (<div>Story Box</div>);
+    const now = new Date();
+
+    const topicsList = ['HTML', 'JavaScript', 'React'];
+
+    return (<div>
+      <h3>Stories</h3>
+      <p className="lead">
+        Current time: {now.toTimeString()}
+        </p>
+      <ul>
+        {topicsList.map((topic, index) => <li key={index}>{topic}</li>)}
+      </ul>
+    </div>);
   }
 }