[New] add quoteStyle option

Author: ljharb

index.js

@@ -13,6 +13,12 @@ var inspectCustom = require('./util.inspect').custom;
 var inspectSymbol = (inspectCustom && isSymbol(inspectCustom)) ? inspectCustom : null;
 
 module.exports = function inspect_ (obj, opts, depth, seen) {
+    if (!opts) opts = {};
+
+    if (has(opts, 'quoteStyle') && (opts.quoteStyle !== 'single' && opts.quoteStyle !== 'double')) {
+        throw new TypeError('option "quoteStyle" must be "single" or "double"');
+    }
+
     if (typeof obj === 'undefined') {
         return 'undefined';
     }
@@ -22,8 +28,9 @@ module.exports = function inspect_ (obj, opts, depth, seen) {
     if (typeof obj === 'boolean') {
         return obj ? 'true' : 'false';
     }
+
     if (typeof obj === 'string') {
-        return inspectString(obj);
+        return inspectString(obj, opts);
     }
     if (typeof obj === 'number') {
       if (obj === 0) {
@@ -32,8 +39,6 @@ module.exports = function inspect_ (obj, opts, depth, seen) {
       return String(obj);
     }
 
-    if (!opts) opts = {};
-
     var maxDepth = typeof opts.depth === 'undefined' ? 5 : opts.depth;
     if (typeof depth === 'undefined') depth = 0;
     if (depth >= maxDepth && maxDepth > 0 && typeof obj === 'object') {
@@ -65,7 +70,7 @@ module.exports = function inspect_ (obj, opts, depth, seen) {
         var s = '<' + String(obj.nodeName).toLowerCase();
         var attrs = obj.attributes || [];
         for (var i = 0; i < attrs.length; i++) {
-            s += ' ' + attrs[i].name + '="' + quote(attrs[i].value) + '"';
+            s += ' ' + attrs[i].name + '=' + wrapQuotes(quote(attrs[i].value), 'double', opts);
         }
         s += '>';
         if (obj.childNodes && obj.childNodes.length) s += '...';
@@ -119,6 +124,11 @@ module.exports = function inspect_ (obj, opts, depth, seen) {
     return String(obj);
 };
 
+function wrapQuotes (s, defaultStyle, opts) {
+    var quoteChar = (opts.quoteStyle || defaultStyle) === 'double' ? '"' : "'";
+    return quoteChar + s + quoteChar;
+}
+
 function quote (s) {
     return String(s).replace(/"/g, '&quot;');
 }
@@ -197,9 +207,9 @@ function isElement (x) {
     ;
 }
 
-function inspectString (str) {
+function inspectString (str, opts) {
     var s = str.replace(/(['\\])/g, '\\$1').replace(/[\x00-\x1f]/g, lowbyte);
-    return "'" + s + "'";
+    return wrapQuotes(s, 'single', opts);
 }
 
 function lowbyte (c) {

readme.markdown

@@ -43,8 +43,10 @@ var inspect = require('object-inspect')
 
 ## var s = inspect(obj, opts={})
 
-Return a string `s` with the string representation of `obj` up to a depth of
-`opts.depth`.
+Return a string `s` with the string representation of `obj` up to a depth of `opts.depth`.
+
+Additional options:
+  - `quoteStyle`: must be "single" or "double", if present
 
 # install
 

test/element.js

@@ -2,7 +2,7 @@ var inspect = require('../');
 var test = require('tape');
 
 test('element', function (t) {
-    t.plan(1);
+    t.plan(3);
     var elem = {
         nodeName: 'div',
         attributes: [ { name: 'class', value: 'row' } ],
@@ -11,6 +11,8 @@ test('element', function (t) {
     };
     var obj = [ 1, elem, 3 ];
     t.deepEqual(inspect(obj), '[ 1, <div class="row"></div>, 3 ]');
+    t.deepEqual(inspect(obj, { quoteStyle: 'single' }), "[ 1, <div class='row'></div>, 3 ]");
+    t.deepEqual(inspect(obj, { quoteStyle: 'double' }), '[ 1, <div class="row"></div>, 3 ]');
 });
 
 test('element no attr', function (t) {

test/quoteStyle.js

@@ -0,0 +1,17 @@
+'use strict';
+
+var inspect = require('../');
+var test = require('tape');
+
+test('quoteStyle option', function (t) {
+    t['throws'](function () { inspect(null, { quoteStyle: false }); }, 'false is not a valid value');
+    t['throws'](function () { inspect(null, { quoteStyle: true }); }, 'true is not a valid value');
+    t['throws'](function () { inspect(null, { quoteStyle: '' }); }, '"" is not a valid value');
+    t['throws'](function () { inspect(null, { quoteStyle: {} }); }, '{} is not a valid value');
+    t['throws'](function () { inspect(null, { quoteStyle: [] }); }, '[] is not a valid value');
+    t['throws'](function () { inspect(null, { quoteStyle: 42 }); }, '42 is not a valid value');
+    t['throws'](function () { inspect(null, { quoteStyle: NaN }); }, 'NaN is not a valid value');
+    t['throws'](function () { inspect(null, { quoteStyle: function () {} }); }, 'a function is not a valid value');
+
+    t.end();
+});

test/values.js

@@ -107,7 +107,11 @@ test('Strings', function (t) {
     var str = 'abc';
 
     t.equal(inspect(str), "'" + str + "'", 'primitive string shows as such');
+    t.equal(inspect(str, { quoteStyle: 'single' }), "'" + str + "'", 'primitive string shows as such, single quoted');
+    t.equal(inspect(str, { quoteStyle: 'double' }), '"' + str + '"', 'primitive string shows as such, double quoted');
     t.equal(inspect(Object(str)), 'Object(' + inspect(str) + ')', 'String object shows as such');
+    t.equal(inspect(Object(str), { quoteStyle: 'single' }), 'Object(' + inspect(str, { quoteStyle: 'single' }) + ')', 'String object shows as such, single quoted');
+    t.equal(inspect(Object(str), { quoteStyle: 'double' }), 'Object(' + inspect(str, { quoteStyle: 'double' }) + ')', 'String object shows as such, double quoted');
 
     t.end();
 });