chore: allow minimal height for trace attachments (#32996)

packages/trace-viewer/src/ui/attachmentsTab.tsx

@@ -20,7 +20,7 @@ import { ImageDiffView } from '@web/shared/imageDiffView';
 import type { MultiTraceModel } from './modelUtil';
 import { PlaceholderPanel } from './placeholderPanel';
 import type { AfterActionTraceEventAttachment } from '@trace/trace';
-import { CodeMirrorWrapper } from '@web/components/codeMirrorWrapper';
+import { CodeMirrorWrapper, lineHeight } from '@web/components/codeMirrorWrapper';
 import { isTextualMimeType } from '@isomorphic/mimeType';
 import { Expandable } from '@web/components/expandable';
 import { linkifyText } from '@web/renderUtils';
@@ -51,6 +51,11 @@ const ExpandableAttachment: React.FunctionComponent<ExpandableAttachmentProps> =
     }
   }, [expanded, attachmentText, placeholder, attachment]);
 
+  const snippetHeight = React.useMemo(() => {
+    const lineCount = attachmentText ? attachmentText.split('\n').length : 0;
+    return Math.min(Math.max(5, lineCount), 20) * lineHeight;
+  }, [attachmentText]);
+
   const title = <span style={{ marginLeft: 5 }}>
     {linkifyText(attachment.name)} {hasContent && <a style={{ marginLeft: 5 }} href={downloadURL(attachment)}>download</a>}
   </span>;
@@ -62,14 +67,16 @@ const ExpandableAttachment: React.FunctionComponent<ExpandableAttachmentProps> =
     <Expandable title={title} expanded={expanded} setExpanded={setExpanded} expandOnTitleClick={true}>
       {placeholder && <i>{placeholder}</i>}
     </Expandable>
-    {expanded && attachmentText !== null && <CodeMirrorWrapper
+    {expanded && attachmentText !== null && <div className='vbox' style={{ height: snippetHeight }}>
+      <CodeMirrorWrapper
         text={attachmentText}
         readOnly
         mimeType={attachment.contentType}
         linkify={true}
         lineNumbers={true}
         wrapLines={false}>
-    </CodeMirrorWrapper>}
+      </CodeMirrorWrapper>
+    </div>}
   </>;
 };
 

packages/web/src/components/codeMirrorWrapper.tsx

@@ -28,6 +28,8 @@ export type SourceHighlight = {
 
 export type Language = 'javascript' | 'python' | 'java' | 'csharp' | 'jsonl' | 'html' | 'css' | 'markdown';
 
+export const lineHeight = 20;
+
 export interface SourceProps {
   text: string;
   language?: Language;