no-extra-strict: disallow strict mode directives when already in strict mode

This rule was removed in ESLint v1.0 and replaced by the strict rule. The "global" or "function" options in the new rule are similar to the removed rule.

The "use strict"; directive applies to the scope in which it appears and all inner scopes contained within that scope. Therefore, using the "use strict"; directive in one of these inner scopes is unnecessary.

"use strict";

(function () {
    "use strict";
    var foo = true;
}());

Rule Details

This rule is aimed at preventing unnecessary "use strict"; directives. As such, it will warn when it encounters a "use strict"; directive when already in strict mode.

Example of incorrect code for this rule:

"use strict";

(function () {
    "use strict";
    var foo = true;
}());

Examples of correct code for this rule:

"use strict";

(function () {
    var foo = true;
}());

(function () {
    "use strict";
    var foo = true;
}());

Further Reading

• The ECMAScript 5 Annotated Specification - Strict Mode

Version

This rule was introduced in ESLint 0.3.0 and removed in 1.0.0-rc-1.

Resources

• Documentation source