isTrueish

docs/underscore.util.strings.js.md

@@ -57,6 +57,28 @@ _.implode(["H", "o", "m", "e", "r"]);
 
 --------------------------------------------------------------------------------
 
+#### isTrueish
+
+**Signature:** `_.isTrueish(value:String)`
+
+Checks whether an optional string parses to `true` with JSON. Lowercases variable before checking to ensure strings like `"True"` evaluate properly.
+
+```javascript
+_.isTrueish();
+// => false
+
+_.isTrueish(true);
+// => true
+
+_.isTrueish('true');
+// => true
+
+_.isTrueish('FaLsE');
+// => false
+```
+
+--------------------------------------------------------------------------------
+
 #### strContains
 
 **Signature:** `_.strContains(str:String, search:String)`
@@ -95,4 +117,4 @@ _.toQuery({ forms: { perfect: "circle", imperfect: "square" } });
 // => "forms%5Bperfect%5D=circle&forms%5Bimperfect%5D=square"
 ```
 
---------------------------------------------------------------------------------
+--------------------------------------------------------------------------------

test/util.strings.js

@@ -30,6 +30,18 @@ $(document).ready(function() {
     assert.equal(_.implode(['H','o','m','e','r']), 'Homer', 'Should implode an array of characters into a single string.');
   });
 
+  QUnit.test('isTrueish', function(assert) {
+    assert.equal(_.isTrueish(), false, 'should return false');
+    assert.equal(_.isTrueish(undefined), false, 'should return false');
+    assert.equal(_.isTrueish(null), false, 'should return false');
+    assert.equal(_.isTrueish(true), true, 'should return true');
+    assert.equal(_.isTrueish(false), false, 'should return false');
+    assert.equal(_.isTrueish('true'), true, 'should return true');
+    assert.equal(_.isTrueish('false'), false, 'should return false');
+    assert.equal(_.isTrueish('True'), true, 'should return true');
+    assert.equal(_.isTrueish('FaLsE'), false, 'should return false');
+  });
+
   QUnit.test('camelCase', function(assert) {
     assert.equal(_.camelCase('punic-wars'), 'punicWars', 'Should convert a dashed-format string to camelCase.');
   });

underscore.util.strings.js

@@ -103,6 +103,14 @@
       return a.join('');
     },
 
+    // Checks whether a string is "trueish"
+    isTrueish: function(v) {
+      if(_.isBoolean(v)) {
+          return v;
+      }
+      return !!JSON.parse((v || "false").toLowerCase());
+    },
+
     // Converts a string to camel case
     camelCase : function( string ){
       return  string.replace(/-([a-z])/g, function (g) { return g[1].toUpperCase(); });