[diffs] Fix for theme changes on collapsed files

packages/diffs/src/renderers/DiffHunksRenderer.ts

@@ -472,45 +472,60 @@ export class DiffHunksRenderer<LAnnotation = undefined> {
       };
       forceHighlight = false;
     }
-    const forcePlainText = isDiffMassive(diff, this.getTokenizeMaxLength());
     this.renderCache ??= {
       diff,
       highlighted: false,
       options,
       result: undefined,
       renderRange: undefined,
     };
+    const hasContent =
+      diff.additionLines.length > 0 || diff.deletionLines.length > 0;
+    const forcePlainText =
+      !hasContent ||
+      isDiffPlainText(diff) ||
+      isDiffMassive(diff, this.getTokenizeMaxLength());
+    const newContent = !areDiffTargetsEqual(diff, this.renderCache.diff);
+    const newRenderRange = !areRenderRangesEqual(
+      this.renderCache.renderRange,
+      renderRange
+    );
     if (this.workerManager?.isWorkingPool() === true) {
       if (
         forcePlainText ||
         this.renderCache.result == null ||
-        (!this.renderCache.highlighted &&
-          (!areDiffTargetsEqual(diff, this.renderCache.diff) ||
-            !areRenderRangesEqual(this.renderCache.renderRange, renderRange)))
+        (!this.renderCache.highlighted && (newContent || newRenderRange))
       ) {
         this.renderCache.diff = diff;
         this.renderCache.options = options;
         this.renderCache.highlighted = false;
-        this.renderCache.result = this.workerManager.getPlainDiffAST(
-          diff,
-          renderRange.startingLine,
-          renderRange.totalLines,
-          // If we aren't using a windowed render, then we need to render
-          // everything
-          isDefaultRenderRange(renderRange)
-            ? true
-            : expandUnchanged
+        if (
+          this.renderCache.result == null ||
+          newContent ||
+          newRenderRange ||
+          forceHighlight
+        ) {
+          this.renderCache.result = this.workerManager.getPlainDiffAST(
+            diff,
+            renderRange.startingLine,
+            renderRange.totalLines,
+            // If we aren't using a windowed render, then we need to render
+            // everything
+            isDefaultRenderRange(renderRange)
               ? true
-              : this.expandedHunks,
-          collapsedContextThreshold
-        );
+              : expandUnchanged
+                ? true
+                : this.expandedHunks,
+            collapsedContextThreshold
+          );
+        }
         this.renderCache.renderRange = renderRange;
       }
+
+      // Should we kick off an async highlight process
       if (
-        // We should only attempt to kick off the worker highlighter if there
-        // are lines to render
-        renderRange.totalLines > 0 &&
         !forcePlainText &&
+        hasContent &&
         (!this.renderCache.highlighted || forceHighlight)
       ) {
         this.workerManager.highlightDiffAST(this, diff);

packages/diffs/src/renderers/FileRenderer.ts

@@ -233,44 +233,53 @@ export class FileRenderer<LAnnotation = undefined> {
       };
       forceHighlight = false;
     }
-    const lines = this.getOrCreateLineCache(file);
-    const forcePlainText = isFileMassive(
-      lines.length,
-      this.getTokenizeMaxLength()
-    );
     this.renderCache ??= {
       file,
       highlighted: false,
       options,
       result: undefined,
       renderRange: undefined,
     };
+    const lines = this.getOrCreateLineCache(file);
+    const hasContent = file.contents.length > 0;
+    const forcePlainText =
+      !hasContent ||
+      isFilePlainText(file) ||
+      isFileMassive(lines.length, this.getTokenizeMaxLength());
+    const newContent = !areFilesEqual(file, this.renderCache.file);
+    const newRenderRange = !areRenderRangesEqual(
+      this.renderCache.renderRange,
+      renderRange
+    );
     if (this.workerManager?.isWorkingPool() === true) {
       // Cache invalidation based on renderRange comparison
       if (
-        this.renderCache.result == null ||
         forcePlainText ||
-        (!this.renderCache.highlighted &&
-          (!areFilesEqual(file, this.renderCache.file) ||
-            !areRenderRangesEqual(this.renderCache.renderRange, renderRange)))
+        this.renderCache.result == null ||
+        (!this.renderCache.highlighted && (newContent || newRenderRange))
       ) {
         this.renderCache.file = file;
         this.renderCache.options = options;
         this.renderCache.highlighted = false;
-        this.renderCache.result = this.workerManager.getPlainFileAST(
-          file,
-          renderRange.startingLine,
-          renderRange.totalLines,
-          lines
-        );
+        if (
+          this.renderCache.result == null ||
+          newContent ||
+          newRenderRange ||
+          forceHighlight
+        ) {
+          this.renderCache.result = this.workerManager.getPlainFileAST(
+            file,
+            renderRange.startingLine,
+            renderRange.totalLines,
+            lines
+          );
+        }
         this.renderCache.renderRange = renderRange;
       }
 
       if (
-        // We should only attempt to kick off the worker highlighter if there
-        // are lines to render
-        renderRange.totalLines > 0 &&
         !forcePlainText &&
+        hasContent &&
         (!this.renderCache.highlighted || forceHighlight)
       ) {
         this.workerManager.highlightFileAST(this, file);