fix: JSONL files not opening in preview (ASTD-261)

web/packages/studio/src/components/FilesetFilePreviewPanel/FilesetFilePreviewContent/index.tsx

@@ -63,11 +63,7 @@ export const FilesetFilePreviewContent: FC<FilesetFilePreviewContentProps> = ({
   hideHeader = false,
   enabled = true,
 }) => {
-  const { isBinary: binary, isLoading: isBinaryLoading } = useIsBinaryFile(
-    workspace,
-    filesetName,
-    filePath
-  );
+  const { isBinary: binary, isLoading: isBinaryLoading } = useIsBinaryFile(filePath);
 
   const {
     data: internalContent,

web/packages/studio/src/components/filesets/hooks/useIsBinaryFile.test.ts

@@ -0,0 +1,69 @@
+// SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+import { useIsBinaryFile } from '@studio/components/filesets/hooks/useIsBinaryFile';
+import { renderHook } from '@testing-library/react';
+
+describe('useIsBinaryFile', () => {
+  it('returns isBinary=false for .jsonl files', () => {
+    const { result } = renderHook(() => useIsBinaryFile('data/test.jsonl'));
+
+    expect(result.current).toEqual({ isBinary: false, isLoading: false });
+  });
+
+  it('returns isBinary=false for .json files', () => {
+    const { result } = renderHook(() => useIsBinaryFile('config.json'));
+
+    expect(result.current).toEqual({ isBinary: false, isLoading: false });
+  });
+
+  it('returns isBinary=false for .csv files', () => {
+    const { result } = renderHook(() => useIsBinaryFile('data.csv'));
+
+    expect(result.current).toEqual({ isBinary: false, isLoading: false });
+  });
+
+  it('returns isBinary=false for .py files', () => {
+    const { result } = renderHook(() => useIsBinaryFile('script.py'));
+
+    expect(result.current).toEqual({ isBinary: false, isLoading: false });
+  });
+
+  it('returns isBinary=false for .yaml and .yml files', () => {
+    const { result: yamlResult } = renderHook(() => useIsBinaryFile('config.yaml'));
+    const { result: ymlResult } = renderHook(() => useIsBinaryFile('config.yml'));
+
+    expect(yamlResult.current).toEqual({ isBinary: false, isLoading: false });
+    expect(ymlResult.current).toEqual({ isBinary: false, isLoading: false });
+  });
+
+  it('returns isBinary=false for .md files', () => {
+    const { result } = renderHook(() => useIsBinaryFile('README.md'));
+
+    expect(result.current).toEqual({ isBinary: false, isLoading: false });
+  });
+
+  it('returns isBinary=false when filePath is undefined', () => {
+    const { result } = renderHook(() => useIsBinaryFile(undefined));
+
+    expect(result.current).toEqual({ isBinary: false, isLoading: false });
+  });
+
+  it('returns isBinary=true for .png files (binary blocklist)', () => {
+    const { result } = renderHook(() => useIsBinaryFile('image.png'));
+
+    expect(result.current).toEqual({ isBinary: true, isLoading: false });
+  });
+
+  it('returns isBinary=true for .zip files (binary blocklist)', () => {
+    const { result } = renderHook(() => useIsBinaryFile('archive.zip'));
+
+    expect(result.current).toEqual({ isBinary: true, isLoading: false });
+  });
+
+  it('returns isBinary=false for unknown extensions (fail-open)', () => {
+    const { result } = renderHook(() => useIsBinaryFile('data.unknown'));
+
+    expect(result.current).toEqual({ isBinary: false, isLoading: false });
+  });
+});

web/packages/studio/src/components/filesets/hooks/useIsBinaryFile.ts

@@ -1,79 +1,31 @@
 // SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-// Importing from the SDK fetchers module activates the Axios interceptor that
-// injects the OIDC Bearer token, so axios.head() calls below are auth-aware.
-import '@nemo/sdk/generated/fetchers/platform';
-import { getFilesDownloadFileQueryKey } from '@nemo/sdk/generated/platform/api';
+import { KNOWN_TEXT_EXTENSIONS } from '@studio/constants/constants';
 import { isBinaryExtension } from '@studio/util/binaryFile';
-import { useQuery } from '@tanstack/react-query';
-import axios from 'axios';
+
+function isKnownTextExtension(path: string): boolean {
+  const ext = path.split('.').at(-1)?.toLowerCase();
+  return ext !== undefined && KNOWN_TEXT_EXTENSIONS.has(ext);
+}
 
 /**
  * Determine whether a fileset file should be treated as binary (no text preview).
  *
- * Strategy (three tiers):
- *   1. Extension in `BINARY_FILE_EXTENSIONS` → binary immediately, no network.
- *   2. Extension not in blocklist → HEAD request; `Content-Type` header decides.
- *      - `text/*` or known text application types → not binary.
- *      - Everything else → binary.
- *   3. HEAD fails / no Content-Type → assume text (fail-open for preview).
+ * Strategy:
+ *   - Extension in `KNOWN_TEXT_EXTENSIONS` → text immediately.
+ *   - Extension in `BINARY_FILE_EXTENSIONS` → binary immediately.
+ *   - Unknown extension → assume text (fail-open for preview).
  *
- * Returns `{ isBinary, isLoading }`. `isLoading` is true only during the HEAD
- * request (tier-2 path); tier-1 resolves synchronously.
+ * Returns `{ isBinary, isLoading }`. `isLoading` is always `false` since
+ * detection is synchronous.
  */
-export function useIsBinaryFile(
-  workspace: string,
-  filesetName: string,
-  filePath: string | undefined
-): { isBinary: boolean; isLoading: boolean } {
-  const blocklisted = filePath !== undefined && isBinaryExtension(filePath);
-
-  const { data: headBinary, isPending } = useQuery({
-    queryKey: ['file-content-type', workspace, filesetName, filePath],
-    queryFn: async (): Promise<boolean> => {
-      if (!filePath) return false;
-      try {
-        // axios.head() is auth-aware via the interceptor registered when
-        // '@nemo/sdk/generated/fetchers/platform' is imported above.
-        const [fileUrl] = getFilesDownloadFileQueryKey(
-          encodeURIComponent(workspace),
-          encodeURIComponent(filesetName),
-          encodeURIComponent(filePath)
-        );
-        const res = await axios.head(fileUrl);
-        const ct = String(res.headers['content-type'] ?? '');
-        return !isTextContentType(ct);
-      } catch {
-        return false; // fail-open: assume text
-      }
-    },
-    enabled: !!filePath && !blocklisted,
-    staleTime: Infinity,
-    retry: false,
-  });
-
-  if (blocklisted) return { isBinary: true, isLoading: false };
+export function useIsBinaryFile(filePath: string | undefined): {
+  isBinary: boolean;
+  isLoading: boolean;
+} {
   if (!filePath) return { isBinary: false, isLoading: false };
-  return { isBinary: headBinary ?? false, isLoading: isPending };
-}
-
-const TEXT_CONTENT_TYPES = [
-  'text/',
-  'application/json',
-  'application/xml',
-  'application/javascript',
-  'application/typescript',
-  'application/yaml',
-  'application/x-yaml',
-  'application/toml',
-  'application/csv',
-  'application/x-sh',
-];
-
-function isTextContentType(ct: string): boolean {
-  // Extract the MIME type token only (strip "; charset=..." parameters) before
-  // matching, so parameter values can't accidentally trigger a false positive.
-  const mimeToken = ct.split(';')[0].trim().toLowerCase();
-  return TEXT_CONTENT_TYPES.some((prefix) => mimeToken.startsWith(prefix));
+  if (isKnownTextExtension(filePath)) return { isBinary: false, isLoading: false };
+  if (isBinaryExtension(filePath)) return { isBinary: true, isLoading: false };
+  return { isBinary: false, isLoading: false };
 }

web/packages/studio/src/constants/constants.ts

@@ -20,3 +20,59 @@ export const DEFAULT_TOOLS_FILE_NAME = 'tools.json';
 export const EMPTY_FIELD_VALUE = '-';
 export const EMPTY_FIELD_EMDASH_VALUE = '—';
 export const DEFAULT_BUILD_MODEL_NAME = 'nvidia-llama-3-3-nemotron-super-49b-v1';
+
+export const KNOWN_TEXT_EXTENSIONS = new Set([
+  // Data
+  'json',
+  'jsonl',
+  'csv',
+  'tsv',
+  // Code
+  'py',
+  'js',
+  'jsx',
+  'ts',
+  'tsx',
+  'java',
+  'c',
+  'cpp',
+  'h',
+  'go',
+  'rs',
+  'rb',
+  'php',
+  'swift',
+  'kt',
+  'scala',
+  'r',
+  'm',
+  'sh',
+  'bash',
+  'zsh',
+  'fish',
+  // Markup / Config
+  'html',
+  'htm',
+  'xml',
+  'yaml',
+  'yml',
+  'toml',
+  'ini',
+  'cfg',
+  'conf',
+  'jsonc',
+  'env',
+  // Text
+  'txt',
+  'md',
+  'rst',
+  'log',
+  'diff',
+  'patch',
+  // Other
+  'sql',
+  'graphql',
+  'proto',
+  'dockerfile',
+  'makefile',
+]);