Trying to optimize and improve readability through better abstraction

Trying to optimise code, and improve abstraction for better readability

Hopefully responding to the concerns of @RubenVerborgh: #1109 (comment) and #1109 (comment)

Author: megoth

lib/resource-mapper.js

@@ -25,7 +25,7 @@ class ResourceMapper {
     this._defaultContentType = defaultContentType
     this._indexFilename = indexFilename
     this._types = { ...types, ...overrideTypes }
-    this._suffixes = fileSuffixes
+    this._isControlFile = new RegExp(`.(?:${fileSuffixes.join('|')})$`)
 
     // If the host needs to be replaced on every call, pre-split the root URL
     if (includeHost) {
@@ -92,10 +92,13 @@ class ResourceMapper {
 
   async _getMatchingFile (folder, filename, isIndex) {
     const files = await this._readdir(folder)
-
-    // Find a file with the same name (minus the dollar extension)
-    return (files.find(f => this._removeDollarExtension(f) === filename ||
-      (isIndex && f.startsWith(this._indexFilename + '.') && !this._suffixes.some(suffix => f.endsWith(suffix)))))
+    const hasSameName = (f) => {
+      return this._removeDollarExtension(f) === filename
+    }
+    const isIndexFile = (f) => {
+      return isIndex && f.startsWith(this._indexFilename + '.') && !this._isControlFile.test(f)
+    }
+    return files.find(f => hasSameName(f) || isIndexFile(f))
   }
 
   async getRepresentationUrlForResource (resourceUrl) {

test/unit/resource-mapper-test.js

@@ -286,6 +286,18 @@ describe('ResourceMapper', () => {
         contentType: 'application/octet-stream'
       })
 
+    itMapsUrl(mapper, 'a URL of that has an accompanying acl file, but no actual file',
+      {
+        url: 'http://localhost/space/'
+      },
+      [
+        `${rootPath}space/index.acl`
+      ],
+      {
+        path: `${rootPath}space/`,
+        contentType: 'application/octet-stream'
+      })
+
     itMapsUrl(mapper, 'a URL ending with a slash to an index file for text/html when index.html not is available',
       {
         url: 'http://localhost/space/',
@@ -297,6 +309,20 @@ describe('ResourceMapper', () => {
         contentType: 'text/html'
       })
 
+    itMapsUrl(mapper, 'a URL of that has an accompanying meta file, but no actual file',
+      {
+        url: 'http://localhost/space/',
+        contentType: 'text/html',
+        createIfNotExists: true
+      },
+      [
+        `${rootPath}space/index.meta`
+      ],
+      {
+        path: `${rootPath}space/index.html`,
+        contentType: 'text/html'
+      })
+
     itMapsUrl(mapper, 'a URL ending with a slash to a folder when index is skipped',
       {
         url: 'http://localhost/space/',