.jshintrc

/*!
 * Options for JSHint, a JavaScript code quality checking tool.
 * https://jshint.com/docs/options/
 */

// These defaults are for code that is:
// -   executed directly by the web browser (i.e., not transpiled)
// -   on public-facing web sites (i.e., not internal)
//
// For Node.js:
//     /*jshint esversion: 8, node: true */
//
// For JavaScript code that gets transpiled:
//     /*jshint esversion: 8 */
//
// While developing, to enable globals used for poor-man's debugging,
// such as `console` and `alert`:
//     /*jshint devel: true */
//
// For internal web sites (ours or clients') that don't require IE11:
//     /*jshint esversion: 8 */

{
    // enforcing options
    "bitwise":       true,  // `true` prohibits bitwise operators, e.g., `&`, `|`, `^`.
    "curly":         true,  // `true` requires `{}` around blocks in loops and conditionals.
    "eqeqeq":        true,  // `true` prohibits use of `==` and `!=`, in favor of `===` and `!==`.
    "esversion":     5,     // ECMAScript 5.  IE11 baseline, mainly for legacy corporate environments.
    "forin":         true,  // `true` requires all `for in` loops to filter objects' items.
    "freeze":        true,  // `true` prohibits overwriting prototypes of native objects, such as `Array`, `Date`, and `Object`.
    "futurehostile": true,  // `true` warns about future reserved words.
    "latedef":       true,  // `true` prohibits use of variables before their definitions.
    "leanswitch":    true,  // `true` prohibits unnecessary `switch` statement clauses.
    "maxerr":        100,   // Maximum number of warnings before JSHint gives up.
    "noarg":         true,  // `true` prohibits the use of `arguments.caller` and `arguments.callee`.
    "nocomma":       true,  // `true` prohibits use of the comma operator.
    "nonbsp":        true,  // `true` warns about U+00A0 NO-BREAK SPACE characters.
    "nonew":         true,  // `true` prohibits the use of constructors for side-effects.
    "noreturnawait": true,  // `true` prohibits `return await`, in favor of returning the results of asynchronous operations directly.
    "regexpu":       false, // `true` warns about regular expressions not including the `u` flag.
    "shadow":        false, // `false` checks for duplicate variable declarations in the same scope only.
    "singleGroups":  true,  // `true` prohibits unnecessary use of the grouping operator.
    "strict":        false, // `false` disables warnings about strict mode.
    "trailingcomma": false, // `true` warns when a comma is not placed after the last element of an array or object literal.
    "undef":         true,  // `true` prohibits the use of variables not explicitly declared.
    "unused":        true,  // `true` warns about defined variables that are never used.
    "varstmt":       false, // `true` prohibits the use of `var` statements, in favor of `let` and `const`.

    // relaxing options
    "asi":           false, // `true` to suppress warnings about missing semicolons.
    "boss":          false, // `true` to suppress warnings about the use of assignments where comparisons are expected (e.g., in `if` and `while` conditions)
    "debug":         false, // `true` to suppress warnings about the `debugger` statement, i.e., browser breakpoint.
    "elision":       false, // `true` to allow the use of ES3 array elision elements or empty elements.
    "eqnull":        true,  // `true` to suppress warnings about `== null` comparisons.  Only `null` and `undefined` are `== null`.
    "evil":          false, // `true` to suppress warnings about the use of `eval`.
    "expr":          false, // `true` to suppress warnings about the use of expressions where assignments and function calls are expected.
    "funcscope":     false, // `true` to suppress warnings about declaring variables inside control structures that are then used outside of them.
    "iterator":      false, // `true` to suppress warnings about the `__iterator__` property.
    "lastsemic":     false, // `true` to suppress warnings about the missing semicolon for the last statement in a one-line block.
    "loopfunc":      false, // `true` to suppress warnings about functions inside of loops.
    "moz":           false, // `true` to allow the use of Mozilla JavaScript extensions.
    "notypeof":      false, // `true` to suppress warnings about invalid `typeof` operator values.
    "noyield":       false, // `true` to suppress warnings about generator functions containing no `yield` statements.
    "plusplus":      false, // `true` to prohibit the use of `++` and `--` unary operators.
    "proto":         false, // `true` to suppress warnings about the `__proto__` property.
    "scripturl":     false, // `true` to suppress warnings about the use of script-targeted URLs, e.g., `javascript:...`.
    "supernew":      false, // `true` to suppress warnings about certain "weird" constructions.
    "validthis":     false, // `true` to suppress warnings about the use of `this` in non-constructor functions in strict mode.
    "withstmt":      false, // `true` to suppress warnings about the use of the `with` statement.

    // environment options
    "browser":       true   // globals exposed by modern web browsers, such as `document`, `navigator`, and `FileReader`.
}