chore(v2): normalize url properly (#1105)

* refactor(v2): normalize url properly

* nits

v2/lib/load/utils.js

@@ -77,6 +77,67 @@ function parse(fileString) {
   return {metadata, content};
 }
 
+function normalizeUrl(rawUrls) {
+  const urls = rawUrls;
+  const resultArray = [];
+
+  // If the first part is a plain protocol, we combine it with the next part.
+  if (urls[0].match(/^[^/:]+:\/*$/) && urls.length > 1) {
+    const first = urls.shift();
+    urls[0] = first + urls[0];
+  }
+
+  // There must be two or three slashes in the file protocol, two slashes in anything else.
+  if (urls[0].match(/^file:\/\/\//)) {
+    urls[0] = urls[0].replace(/^([^/:]+):\/*/, '$1:///');
+  } else {
+    urls[0] = urls[0].replace(/^([^/:]+):\/*/, '$1://');
+  }
+
+  // eslint-disable-next-line
+  for (let i = 0; i < urls.length; i++) {
+    let component = urls[i];
+
+    if (typeof component !== 'string') {
+      throw new TypeError(`Url must be a string. Received ${component}`);
+    }
+
+    if (component === '') {
+      // eslint-disable-next-line
+      continue;
+    }
+
+    if (i > 0) {
+      // Removing the starting slashes for each component but the first.
+      component = component.replace(/^[/]+/, '');
+    }
+    if (i < urls.length - 1) {
+      // Removing the ending slashes for each component but the last.
+      component = component.replace(/[/]+$/, '');
+    } else {
+      // For the last component we will combine multiple slashes to a single one.
+      component = component.replace(/[/]+$/, '/');
+    }
+
+    resultArray.push(component);
+  }
+
+  let str = resultArray.join('/');
+  // Each input component is now separated by a single slash except the possible first plain protocol part.
+
+  // remove trailing slash before parameters or hash
+  str = str.replace(/\/(\?|&|#[^!])/g, '$1');
+
+  // replace ? in parameters with &
+  const parts = str.split('?');
+  str = parts.shift() + (parts.length > 0 ? '?' : '') + parts.join('&');
+
+  // dedupe forward slashes
+  str = str.replace(/^\/+/, '/');
+
+  return str;
+}
+
 module.exports = {
   encodePath,
   generate,
@@ -84,5 +145,6 @@ module.exports = {
   fileToComponentName,
   getSubFolder,
   idx,
+  normalizeUrl,
   parse,
 };