New option: impliedStrict

src/index.js

@@ -62,6 +62,7 @@ function defaultOptions() {
         optimistic: false,
         directive: false,
         nodejsScope: false,
+        impliedStrict: false,
         sourceType: 'script',  // one of ['script', 'module']
         ecmaVersion: 5
     };
@@ -103,6 +104,8 @@ function updateDeeply(target, override) {
  * @param {boolean} [providedOptions.nodejsScope=false]- whether the whole
  * script is executed under node.js environment. When enabled, escope adds
  * a function scope immediately following the global scope.
+ * @param {boolean} [providedOptions.impliedStrict=false]- implied strict mode
+ * (if ecmaVersion >= 5).
  * @param {string} [providedOptions.sourceType='script']- the source type of the script. one of 'script' and 'module'
  * @param {number} [providedOptions.ecmaVersion=5]- which ECMAScript version is considered
  * @return {ScopeManager}

src/referencer.js

@@ -392,6 +392,10 @@ export default class Referencer extends esrecurse.Visitor {
             this.scopeManager.__nestModuleScope(node);
         }
 
+        if (this.scopeManager.isStrictModeSupported() && this.scopeManager.isImpliedStrict()) {
+            this.currentScope().isStrict = true;
+        }
+
         this.visitChildren(node);
         this.close(node);
     }

src/scope-manager.js

@@ -73,6 +73,14 @@ export default class ScopeManager {
         return this.__options.sourceType === 'module';
     }
 
+    isImpliedStrict() {
+        return this.__options.impliedStrict;
+    }
+
+    isStrictModeSupported() {
+        return this.__options.ecmaVersion >= 5;
+    }
+
     // Returns appropriate scope for this node.
     __get(node) {
         return this.__nodeToScope.get(node);

test/implied-strict.js

@@ -0,0 +1,125 @@
+// -*- coding: utf-8 -*-
+//  Copyright (C) 2015 Yusuke Suzuki <[email protected]>
+//
+//  Redistribution and use in source and binary forms, with or without
+//  modification, are permitted provided that the following conditions are met:
+//
+//    * Redistributions of source code must retain the above copyright
+//      notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above copyright
+//      notice, this list of conditions and the following disclaimer in the
+//      documentation and/or other materials provided with the distribution.
+//
+//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+//  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+//  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+//  ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+//  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+//  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+//  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+//  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+//  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+//  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import { expect } from 'chai';
+import { parse } from '../third_party/esprima';
+import { analyze } from '..';
+
+describe('impliedStrict option', function() {
+    it('ensures all user scopes are strict if ecmaVersion >= 5', function() {
+        const ast = parse(`
+            function foo() {
+                function bar() {
+                    'use strict';
+                }
+            }
+        `);
+
+        const scopeManager = analyze(ast, {ecmaVersion: 5, impliedStrict: true});
+        expect(scopeManager.scopes).to.have.length(3);
+
+        let scope = scopeManager.scopes[0];
+        expect(scope.type).to.be.equal('global');
+        expect(scope.block.type).to.be.equal('Program');
+        expect(scope.isStrict).to.be.true;
+
+        scope = scopeManager.scopes[1];
+        expect(scope.type).to.be.equal('function');
+        expect(scope.block.type).to.be.equal('FunctionDeclaration');
+        expect(scope.isStrict).to.be.true;
+
+        scope = scopeManager.scopes[2];
+        expect(scope.type).to.be.equal('function');
+        expect(scope.block.type).to.be.equal('FunctionDeclaration');
+        expect(scope.isStrict).to.be.true;
+    });
+
+    it('ensures impliedStrict option is only effective when ecmaVersion option >= 5', function() {
+        const ast = parse(`
+            function foo() {}
+        `);
+
+        const scopeManager = analyze(ast, {ecmaVersion: 3, impliedStrict: true});
+        expect(scopeManager.scopes).to.have.length(2);
+
+        let scope = scopeManager.scopes[0];
+        expect(scope.type).to.be.equal('global');
+        expect(scope.block.type).to.be.equal('Program');
+        expect(scope.isStrict).to.be.false;
+
+        scope = scopeManager.scopes[1];
+        expect(scope.type).to.be.equal('function');
+        expect(scope.block.type).to.be.equal('FunctionDeclaration');
+        expect(scope.isStrict).to.be.false;
+    });
+
+    it('omits a nodejs global scope when ensuring all user scopes are strict', function() {
+        const ast = parse(`
+            function foo() {}
+        `);
+
+        let scopeManager = analyze(ast, {ecmaVersion: 5, nodejsScope: true, impliedStrict: true});
+        expect(scopeManager.scopes).to.have.length(3);
+
+        let scope = scopeManager.scopes[0];
+        expect(scope.type).to.be.equal('global');
+        expect(scope.block.type).to.be.equal('Program');
+        expect(scope.isStrict).to.be.false;
+
+        scope = scopeManager.scopes[1];
+        expect(scope.type).to.be.equal('function');
+        expect(scope.block.type).to.be.equal('Program');
+        expect(scope.isStrict).to.be.true;
+
+        scope = scopeManager.scopes[2];
+        expect(scope.type).to.be.equal('function');
+        expect(scope.block.type).to.be.equal('FunctionDeclaration');
+        expect(scope.isStrict).to.be.true;
+    });
+
+    it('omits a module global scope when ensuring all user scopes are strict', function() {
+        const ast = parse(`
+            function foo() {}`,
+            {sourceType: 'module'}
+        );
+
+        let scopeManager = analyze(ast, {ecmaVersion: 6, impliedStrict: true, sourceType: 'module'});
+        expect(scopeManager.scopes).to.have.length(3);
+
+        let scope = scopeManager.scopes[0];
+        expect(scope.type).to.be.equal('global');
+        expect(scope.block.type).to.be.equal('Program');
+        expect(scope.isStrict).to.be.false;
+
+        scope = scopeManager.scopes[1];
+        expect(scope.type).to.be.equal('module');
+        expect(scope.isStrict).to.be.true;
+
+        scope = scopeManager.scopes[2];
+        expect(scope.type).to.be.equal('function');
+        expect(scope.block.type).to.be.equal('FunctionDeclaration');
+        expect(scope.isStrict).to.be.true;
+    });
+});
+
+// vim: set sw=4 ts=4 et tw=80 :