refactor(utils): reorganize functions; move authors file resolution to utils (#6229)

* refactor(utils): reorganize functions; move authors file resolution to utils

* More refactor

packages/docusaurus-utils/src/urlUtils.ts

@@ -0,0 +1,90 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+export function normalizeUrl(rawUrls: string[]): string {
+  const urls = [...rawUrls];
+  const resultArray = [];
+
+  let hasStartingSlash = false;
+  let hasEndingSlash = false;
+
+  // 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.
+  const replacement = urls[0].match(/^file:\/\/\//) ? '$1:///' : '$1://';
+  urls[0] = urls[0].replace(/^([^/:]+):\/*/, replacement);
+
+  // 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 ${typeof component}`);
+    }
+
+    if (component === '') {
+      if (i === urls.length - 1 && hasEndingSlash) {
+        resultArray.push('/');
+      }
+      // eslint-disable-next-line
+      continue;
+    }
+
+    if (component !== '/') {
+      if (i > 0) {
+        // Removing the starting slashes for each component but the first.
+        component = component.replace(
+          /^[/]+/,
+          // Special case where the first element of rawUrls is empty ["", "/hello"] => /hello
+          component[0] === '/' && !hasStartingSlash ? '/' : '',
+        );
+      }
+
+      hasEndingSlash = component[component.length - 1] === '/';
+      // Removing the ending slashes for each component but the last.
+      // For the last component we will combine multiple slashes to a single one.
+      component = component.replace(/[/]+$/, i < urls.length - 1 ? '' : '/');
+    }
+
+    hasStartingSlash = true;
+    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 in the entire path, avoiding protocol slashes.
+  str = str.replace(/([^:]\/)\/+/g, '$1');
+
+  // Dedupe forward slashes at the beginning of the path.
+  str = str.replace(/^\/+/g, '/');
+
+  return str;
+}
+
+export function getEditUrl(
+  fileRelativePath: string,
+  editUrl?: string,
+): string | undefined {
+  return editUrl
+    ? // Don't use posixPath for this: we need to force a forward slash path
+      normalizeUrl([editUrl, fileRelativePath.replace(/\\/g, '/')])
+    : undefined;
+}