Filetreediff: allow users to ignore some files

Filter the added/modified list of files to filter our "ignored files" coming
from the API response.

Requires readthedocs/readthedocs.org#11977

Author: humitos

src/data-validation.js

@@ -257,7 +257,7 @@ const addons_filetreediff = {
       properties: {
         filetreediff: {
           type: "object",
-          required: ["enabled", "diff"],
+          required: ["enabled", "diff", "ignored_files"],
           properties: {
             enabled: { type: "boolean" },
             diff: {
@@ -268,6 +268,7 @@ const addons_filetreediff = {
                 modified: { type: "array" },
               },
             },
+            ignored_files: { type: ["array", "null"] },
           },
         },
       },

src/filetreediff.js

@@ -213,6 +213,15 @@ export class FileTreeDiffElement extends LitElement {
       (f) => f.urls.current === currentUrl,
     );
 
+    // Filter out files that are ignored by this project
+    const ignoredFiles = this.config.addons.filetreediff.ignored_files || [];
+    const addedFiles = diffData.added.filter(
+      (file) => !ignoredFiles.contains(file),
+    );
+    const modifiedFiles = diffData.modified.filter(
+      (file) => !ignoredFiles.contains(file),
+    );
+
     return html`
       <div>
         <div>
@@ -221,8 +230,8 @@ export class FileTreeDiffElement extends LitElement {
             <option value="" ?selected=${!hasCurrentFile} disabled>
               Files changed
             </option>
-            ${renderSection(diffData.added, "Added")}
-            ${renderSection(diffData.modified, "Changed")}
+            ${renderSection(addedFiles, "Added")}
+            ${renderSection(modifiedFiles, "Changed")}
           </select>
         </div>
       </div>