Prevent unnecessary outer directory searches (#1082)

* Prevent unnecessary outer directory searches

Without the added checks, every directory in a source path would be scanned even when the project files have already been found. This can cause avoidable permission errors and thus typedoc to break on out-of-the-box builds for the simplest of projects.

* Stops the search when readme.md and package.json are found.
* Stops the search when `--readme = none` and package.json is found.

* simplify logic

While this commit was taken from the pro-src/master branch, I've
made some changes as appropriate:
- Dropped the specs changes as it seemed unrelated to the test failures
- Fixed bug in `reachedTopDirectory` where it appeared to be
  accidentally inversed
- Fixed merge issues

src/lib/converter/plugins/PackagePlugin.ts

@@ -83,35 +83,31 @@ export class PackagePlugin extends ConverterComponent {
      * @param node  The node that is currently processed if available.
      */
     private onBeginDocument(context: Context, reflection: Reflection, node?: ts.SourceFile) {
+        let packageAndReadmeFound = () => (this.noReadmeFile || this.readmeFile) && this.packageFile;
+        let reachedTopDirectory = dirName => dirName === Path.resolve(Path.join(dirName, '..'));
+        let visitedDirBefore = dirName => this.visited.includes(dirName);
+
         if (!node) {
             return;
         }
-        if (this.readmeFile && this.packageFile) {
-            return;
-        }
 
         const fileName = node.fileName;
-        let dirName: string, parentDir = Path.resolve(Path.dirname(fileName));
-        do {
-            dirName = parentDir;
-            if (this.visited.includes(dirName)) {
-                break;
-            }
-
+        let dirName = Path.resolve(Path.dirname(fileName));
+        while (!packageAndReadmeFound() && !reachedTopDirectory(dirName) && !visitedDirBefore(dirName)) {
             FS.readdirSync(dirName).forEach((file) => {
-                const lfile = file.toLowerCase();
-                if (!this.noReadmeFile && !this.readmeFile && lfile === 'readme.md') {
+                const lowercaseFileName = file.toLowerCase();
+                if (!this.noReadmeFile && !this.readmeFile && lowercaseFileName === 'readme.md') {
                     this.readmeFile = Path.join(dirName, file);
                 }
 
-                if (!this.packageFile && lfile === 'package.json') {
+                if (!this.packageFile && lowercaseFileName === 'package.json') {
                     this.packageFile = Path.join(dirName, file);
                 }
             });
 
             this.visited.push(dirName);
-            parentDir = Path.resolve(Path.join(dirName, '..'));
-        } while (dirName !== parentDir);
+            dirName = Path.resolve(Path.join(dirName, '..'));
+        }
     }
 
     /**