- Improved strict mode detection

Author: Johannes

lib/detectStrictMode.js

@@ -2,11 +2,11 @@
  * Returns true if the source code is intended to run in strict mode. Does not detect
  * "use strict" if it occurs in a nested function.
  *
- * @param {!String} src
+ * @param {String} src
  * @return {Boolean}
  */
 function detectStrictMode(src) {
-    return (/^\s*"use strict";/g).test(src);
+    return (/^\s*(?:"use strict"|'use strict')[ \t]*(?:[\r\n]|;)/g).test(src);
 }
 
 module.exports = detectStrictMode;

package.json

@@ -1,6 +1,6 @@
 {
     "name" : "rewire",
-    "version" : "1.0.1",
+    "version" : "1.0.2",
     "description" : "Dependency injection for node.js applications",
     "keywords" : [
         "dependency",

test/detectStrictMode.test.js

@@ -2,10 +2,20 @@ var expect = require("expect.js"),
     detectStrictMode = require("../lib/detectStrictMode.js");
 
 describe("detectStrictMode", function () {
-    it("should detect \"use strict\"; at the beginning of a string and ignore all whitespace before", function () {
+    it("should detect all valid uses of \"use strict\";", function () {
         expect(detectStrictMode('"use strict";')).to.be(true);
-        expect(detectStrictMode('      "use strict";')).to.be(true);
-        expect(detectStrictMode('  \n "use strict";')).to.be(true);
+        expect(detectStrictMode("'use strict';")).to.be(true);
+        expect(detectStrictMode(' "use strict";')).to.be(true);
+        expect(detectStrictMode('\n"use strict";')).to.be(true);
+        expect(detectStrictMode('\r\n"use strict";')).to.be(true);
+        expect(detectStrictMode('"use strict"\r\n')).to.be(true);
+        expect(detectStrictMode('"use strict" ; test();')).to.be(true);
+    });
+    it("should not detect invalid uses of \"use strict\";", function () {
+        expect(detectStrictMode('" use strict ";')).to.be(false);
+        expect(detectStrictMode('"use strict".replace("use", "fail");')).to.be(false);
+        expect(detectStrictMode('"use strict" .replace("use", "fail");')).to.be(false);
+        expect(detectStrictMode(';"use strict";')).to.be(false);
     });
     it("should not detect \"use strict\"; if it occurs in some nested function", function () {
         expect(detectStrictMode('function () {"use strict";}')).to.be(false);