Clear stale SeqJSON output when switching workspace files (#1889)

* clear stale SeqJSON output when switching workspace files

* show SeqJSON output for untitled sequence files

On initial page load with no file selected, the SeqJSON output pane was empty because no output computation was triggered on mount. Also, typing in an untitled sequence cleared the output because Svelte 4 bypasses prop defaults on reactive updates (has bitten us before). Passing undefined from the parent set sequenceName to undefined instead of the default ''.

Author: AaronPlave

src/components/sequencing/SequenceEditor.svelte

@@ -176,6 +176,12 @@
     debouncedOutputUpdate.cancel();
     dispatchLintChange.cancel();
     previousSequenceFilePath = sequenceFilePath;
+
+    // Clear stale output and recompute for the new file
+    if (editorOutputView) {
+      editorOutputView.dispatch({ changes: { from: 0, insert: '', to: editorOutputView.state.doc.length } });
+      debouncedOutputUpdate(editorSequenceView?.state.doc.toString() ?? '');
+    }
   }
 
   function sequenceUpdateListener(viewUpdate: ViewUpdate): void {
@@ -194,12 +200,8 @@
     if (!preserveAdaptationLog) {
       clearWorkspaceAdaptationMessages();
     }
-
     try {
-      output =
-        sequenceName === undefined
-          ? undefined
-          : selectedOutputFormat?.toOutputFormat?.(sequence, phoenixContext, sequenceName);
+      output = selectedOutputFormat?.toOutputFormat?.(sequence, phoenixContext, sequenceName);
     } catch (e) {
       console.error('Adaptation toOutputFormat error:', e);
       if (sequenceFilePath) {
@@ -364,6 +366,9 @@
       ],
       parent: editorOutputDiv,
     });
+
+    // Compute initial output for the starting content (e.g., untitled empty sequence on page load)
+    debouncedOutputUpdate(editorSequenceView.state.doc.toString());
   });
 
   onDestroy(() => {

src/routes/workspaces/[workspaceId]/+page.svelte

@@ -336,6 +336,7 @@
     }
 
     // successfully navigated, start loading the file contents
+    selectedSequenceOutput = undefined;
     if (nextPath && workspaceTreeMap[nextPath]) {
       const { filename } = separateFilenameFromPath(nextPath);
       const fileType = workspaceTreeMap[nextPath]?.type ?? null;
@@ -1054,7 +1055,7 @@
                 previewOnly={!hasEditFilePermission}
                 sequenceAdaptation={$sequenceAdaptation}
                 sequenceDefinition={$activeDocument.originalContent}
-                sequenceName={$activeDocument.fileName ?? undefined}
+                sequenceName={$activeDocument.fileName ?? ''}
                 sequenceFilePath={$activeDocumentPath ?? ''}
                 sequenceOutput={selectedSequenceOutput}
                 shouldListenForKeyboardSave={false}
@@ -1080,7 +1081,7 @@
                 isLoading={$activeDocumentIsLoading}
                 previewOnly={!hasEditFilePermission}
                 shouldListenForKeyboardSave={false}
-                textFileName={$activeDocument.fileName ?? undefined}
+                textFileName={$activeDocument.fileName ?? ''}
                 textFilePath={$activeDocumentPath ?? ''}
                 textFileContent={$activeDocument.originalContent}
                 on:lintChange={onLintChange}