refactor: improve source parse (#250)

src/plugins/source-plugin.js

@@ -350,40 +350,26 @@ function parseSrcset(input) {
 }
 
 function parseSrc(input) {
-  let startIndex = 0;
-
   if (!input) {
     throw new Error('Must be non-empty');
   }
 
-  for (let position = 0; position < input.length; position++) {
-    const character = input.charAt(position);
+  let startIndex = 0;
+  let value = input;
 
-    if (isASCIIWhitespace(character)) {
-      startIndex = position;
-    } else {
-      break;
-    }
+  while (isASCIIWhitespace(value.substring(0, 1))) {
+    startIndex += 1;
+    value = value.substring(1, value.length);
   }
 
-  if (startIndex === input.length - 1) {
-    throw new Error('Must be non-empty');
+  while (isASCIIWhitespace(value.substring(value.length - 1, value.length))) {
+    value = value.substring(0, value.length - 1);
   }
 
-  let endIndex = input.length;
-
-  for (let position = input.length - 1; position >= 0; position--) {
-    const character = input.charAt(position);
-
-    if (isASCIIWhitespace(character)) {
-      endIndex = position;
-    } else {
-      break;
-    }
+  if (!value) {
+    throw new Error('Must be non-empty');
   }
 
-  const value = input.slice(startIndex, endIndex + 1);
-
   return { value, startIndex };
 }
 

test/fixtures/simple.html

@@ -232,3 +232,21 @@ <h2>An Ordered HTML List</h2>
 <img src=image.png# />
 <img srcset="image.png#hash" />
 <img srcset="image.png#foo 480w, image.png#bar 800w" sizes="(max-width: 600px) 480px, 800px" src="image.png#baz" alt="Elva dressed as a fairy">
+<img src="#" alt="test"/>
+<img src="#" srcset="#" alt="test" />
+<img src="###" srcset="#" alt="test" />
+<img src="   #   " alt="test"/>
+<img src="
+
+
+#
+
+
+" alt="test"/>
+<img src=
+
+
+       image.png
+
+
+/>