Update src/lib/sb-file-uploader-hoc.jsx

src/lib/sb-file-uploader-hoc.jsx

@@ -104,7 +104,7 @@ const SBFileUploaderHOC = function (WrappedComponent) {
             } else {
                 // create <input> element and add it to DOM
                 this.inputElement = document.createElement('input');
-                this.inputElement.accept = '.sb,.sb2,.sb3,.pm,.pmp';
+                this.inputElement.accept = '.sb,.sb2,.sb3,.pm,.pmp,.s4s.txt';
                 this.inputElement.style = 'display: none;';
                 this.inputElement.type = 'file';
                 this.inputElement.onchange = this.handleChange; // connects to step 3
@@ -141,7 +141,7 @@ const SBFileUploaderHOC = function (WrappedComponent) {
                     // Don't update file handle until after confirming replace.
                     const handle = thisFileInput.handle;
                     if (handle) {
-                        if (this.fileToUpload.name.endsWith('.pm') || this.fileToUpload.name.endsWith('.pmp')) {
+                        if (this.fileToUpload.name.endsWith('.pm') || this.fileToUpload.name.endsWith('.s4s.txt') || this.fileToUpload.name.endsWith('.pmp')) {
                             this.props.onSetFileHandle(handle);
                         } else {
                             this.props.onSetFileHandle(null);
@@ -178,7 +178,7 @@ const SBFileUploaderHOC = function (WrappedComponent) {
             if (!fileInputFilename) return '';
             // only parse title with valid scratch project extensions
             // (.sb, .sb2, and .sb3)
-            const matches = fileInputFilename.match(/^(.*)(\.sb[23]?|\.pm|\.pmp)$/);
+            const matches = fileInputFilename.match(/^(.*)(\.sb[23]?|\.pm|\.pmp|\.s4s.txt)$/);
             if (!matches) return '';
             return matches[1].substring(0, 100); // truncate project title to max 100 chars
         }