feat(file): add Compress and Decompress operations to the File block by waleedlatif1 · Pull Request #5100 · simstudioai/sim

waleedlatif1 · 2026-06-16T18:15:48Z

Summary

Add Compress and Decompress operations to the File block — a symmetric zip pair, ZIP-only (the universal interchange format; gzip/tar add nothing for this audience)
Compress bundles one or more workspace files (or upstream file outputs) into a single .zip stored in the workspace; returns the archive in file/files + id/name/size/url. Auto-names from the source file (single) or archive.zip (multiple); explicit Archive Name optional; dedupes entry names
Decompress extracts a .zip back into the workspace, preserving folder structure, and returns the extracted files in files — ready to chain into Get Content or downstream blocks
New file_compress / file_decompress tools + compress/decompress branches on /api/tools/file/manage, archiving via JSZip (DEFLATE)

Safety

Compress: per-file + total input caps (100 MB) to bound in-memory archiving
Decompress: zip-slip guard (rejects ../absolute entry paths), symlink entries skipped, and zip-bomb caps (max entries, per-entry + total uncompressed size, with declared-size pre-check mirroring the existing pptx zip-parser)

Note

Zip doesn't help the original "get an LLM attachment under the 50 MB provider limit" case — models can't read archives. The value here is general file handling: bundling for outbound transfer/storage (compress) and consuming inbound archives (decompress), which was the more common pain.

Type of Change

New feature

Testing

Unit tests for both tools (request body construction + success/failure transforms), 7 passing
bun run check:api-validation passes; typecheck clean; lint clean

Checklist

Code follows project style guidelines
Self-reviewed my changes
Tests added/updated and passing
No new warnings introduced
I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

vercel · 2026-06-16T18:15:54Z

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cursor · 2026-06-16T18:16:03Z

PR Summary

Medium Risk
Decompress writes arbitrary archive bytes into workspace storage with substantial in-memory handling; mitigations are present but archive parsing and extraction remain a sensitive surface area.

Overview
Adds Compress and Decompress to the File v5 block and wires them through new file_compress / file_decompress tools to compress / decompress on /api/tools/file/manage (JSZip DEFLATE).

Compress takes one or more workspace files (IDs or file objects), optional archive name, enforces 100 MB per-file and combined input caps, flattens entry names and dedupes collisions, uploads a .zip to the workspace, and returns the archive in files plus id/name/size/url.

Decompress accepts a single .zip, validates and extracts with zip-slip path sanitization, symlink skipping, entry/count/size limits (including declared uncompressed pre-check and validate-before-write so failures do not leave partial extracts), recreates folder structure via ensureWorkspaceFileFolderPath, and returns extracted files in files.

API contracts, block UI sub-blocks/params, tool registry exports, application/zip extension mapping, block tests, and unit tests for tool request/response transforms are included.

^{Reviewed by Cursor Bugbot for commit cdf521b. Configure here.}

greptile-apps · 2026-06-16T18:23:10Z

Greptile Summary

This PR adds Compress and Decompress operations to the File block, backed by a new JSZip-based implementation in the /api/tools/file/manage route. The feature is well-scoped and follows the existing block/tool/route patterns throughout the codebase.

Compress bundles one or more workspace files into a DEFLATE-compressed .zip, with per-file and total 100 MB input caps, flat-name sanitisation via toFlatFileName, entry deduplication, and auto-naming from the source filename or archive.zip.
Decompress extracts a single .zip back into the workspace with zip-slip protection (sanitizeArchiveEntryPath), symlink-entry skipping, and a two-pass zip-bomb guard (declared-size pre-check + materialized-size cap); extracted files land in workspace folders mirroring the archive's directory structure.
Both operations ship with file_compress/file_decompress tool definitions, Zod contracts, unit tests (7 passing), and are wired into the FileV5Block alongside the existing read/write/append/fetch/get-content operations.

Confidence Score: 5/5

Safe to merge — the compress and decompress paths are well-guarded with size caps, zip-slip protection, and symlink skipping, and the changes are additive with no impact on existing operations.

The implementation is a clean additive feature that correctly follows the existing block/tool/route patterns. All safety-critical paths (zip-slip, zip-bomb, input size) are guarded, the previous review feedback has been addressed, and the only remaining note is a fragility concern around an internal JSZip property used for the bomb pre-check — not a correctness issue since the materialized fallback remains intact.

No files require special attention; route.ts carries the most logic and is worth a quick read-through, but no blocking concerns remain.

Important Files Changed

Filename	Overview
apps/sim/app/api/tools/file/manage/route.ts	Adds ~300 lines for `compress` and `decompress` cases; includes zip-slip guard, symlink skip, two-pass zip-bomb cap (declared + materialised), and deduplication. The pre-check for bomb detection relies on an internal JSZip `_data` field that could silently stop working across versions.
apps/sim/tools/file/compress.ts	New tool definitions for `file_compress` and `file_decompress`; well-structured with correct param visibility, request builder, and transformResponse handlers.
apps/sim/blocks/blocks/file.ts	Adds Compress/Decompress to FileV5Block with correct subblock definitions, tool routing, and params mapping; consistent with existing operation patterns.
apps/sim/lib/api/contracts/tools/file.ts	New Zod schemas for compress (multi-file ID or input, optional archiveName) and decompress (single string fileId); refine guards enforce at least one source is present.
apps/sim/tools/file/compress.test.ts	7 tests covering request body construction, success/failure response transforms for both tools; straightforward and complete.
apps/sim/lib/uploads/utils/file-utils.ts	Adds `zip` and `gz` MIME type mappings to the extension map; small, correct addition.

Sequence Diagram

%%{init: {'theme': 'neutral'}}%%
sequenceDiagram
    participant B as File Block (file.ts)
    participant T as Tool (compress.ts)
    participant R as Route (/api/tools/file/manage)
    participant S as Storage

    Note over B,S: Compress flow
    B->>T: params (compressInput, archiveName)
    T->>R: "POST {operation: compress, fileId[], archiveName}"
    R->>S: getWorkspaceFile(id) x N
    S-->>R: WorkspaceFile[]
    R->>S: downloadFileFromStorage(file) x N
    S-->>R: Buffer[] (capped at 100 MB total)
    R->>R: JSZip.generateAsync(DEFLATE)
    R->>S: uploadWorkspaceFile(zipBuffer)
    S-->>R: result (id, name, url)
    R-->>T: "{success, data: {id, name, size, url, files}}"
    T-->>B: "output.files = [archive]"

    Note over B,S: Decompress flow
    B->>T: params (decompressInput)
    T->>R: "POST {operation: decompress, fileId}"
    R->>S: getWorkspaceFile(id)
    S-->>R: WorkspaceFile
    R->>S: downloadFileFromStorage(archive)
    S-->>R: archiveBuffer (100 MB max)
    R->>R: "JSZip.loadAsync -> validate entries"
    R->>R: sanitizeArchiveEntryPath (zip-slip guard)
    R->>R: declared-size pre-check + materialized-size cap
    loop each safe entry
        R->>S: ensureWorkspaceFileFolderPath(segments)
        R->>S: uploadWorkspaceFile(entryBuffer)
        S-->>R: UserFile
    end
    R-->>T: "{success, data: {files: UserFile[]}}"
    T-->>B: "output.files = extractedFiles"

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sequenceDiagram
    participant B as File Block (file.ts)
    participant T as Tool (compress.ts)
    participant R as Route (/api/tools/file/manage)
    participant S as Storage

    Note over B,S: Compress flow
    B->>T: params (compressInput, archiveName)
    T->>R: "POST {operation: compress, fileId[], archiveName}"
    R->>S: getWorkspaceFile(id) x N
    S-->>R: WorkspaceFile[]
    R->>S: downloadFileFromStorage(file) x N
    S-->>R: Buffer[] (capped at 100 MB total)
    R->>R: JSZip.generateAsync(DEFLATE)
    R->>S: uploadWorkspaceFile(zipBuffer)
    S-->>R: result (id, name, url)
    R-->>T: "{success, data: {id, name, size, url, files}}"
    T-->>B: "output.files = [archive]"

    Note over B,S: Decompress flow
    B->>T: params (decompressInput)
    T->>R: "POST {operation: decompress, fileId}"
    R->>S: getWorkspaceFile(id)
    S-->>R: WorkspaceFile
    R->>S: downloadFileFromStorage(archive)
    S-->>R: archiveBuffer (100 MB max)
    R->>R: "JSZip.loadAsync -> validate entries"
    R->>R: sanitizeArchiveEntryPath (zip-slip guard)
    R->>R: declared-size pre-check + materialized-size cap
    loop each safe entry
        R->>S: ensureWorkspaceFileFolderPath(segments)
        R->>S: uploadWorkspaceFile(entryBuffer)
        S-->>R: UserFile
    end
    R-->>T: "{success, data: {files: UserFile[]}}"
    T-->>B: "output.files = extractedFiles"

_{Reviews (6): Last reviewed commit: "docs(file): correct compress description..." | Re-trigger Greptile}

Adds the inbound half of the archive pair: extracts a .zip back into the workspace with zip-slip path sanitization, symlink skipping, and entry/ size caps to bound zip-bomb expansion. Extracted files are returned in the files output, ready to chain downstream.

- Drop the single 'file' output reintroduced for compress/decompress; v5 intentionally exposes only 'files' (plus id/name/size/url scalars), so compress/decompress reuse the existing surface with no new block output - Add zip/gz to EXTENSION_TO_MIME (previously only in the reverse map), so archive extensions resolve to a real mime instead of octet-stream - Update File v5 block test for the two new operations

- Flatten zip entry names to a safe basename so untrusted fileInput names with .. or / cannot produce zip-slip entry paths (cursor) - Treat archiveName as a flat name landing at the workspace root instead of passing it through splitWorkspaceFilePath, which silently created folders for names with separators (greptile) - Add the upfront empty-input guard before any DB calls, matching the read and content operations (greptile)

waleedlatif1 · 2026-06-16T18:45:20Z

@greptile

waleedlatif1 · 2026-06-16T18:45:21Z

@cursor review

- Read and validate every entry before writing any file, so hitting a size cap no longer leaves partially-extracted files in the workspace (cursor) - Enforce the per-entry cap on the materialized buffer in addition to the declared size, covering entries that omit an uncompressed size (cursor) - Pre-check declared sizes up front to reject standard zip bombs before materializing, and return 422 when no files could be extracted (cursor)

waleedlatif1 · 2026-06-16T18:53:20Z

@greptile

waleedlatif1 · 2026-06-16T18:53:21Z

@cursor review

… decompress - Resolve safe (sanitized) zip entries up front so unsafe/skipped entries no longer count toward the per-entry and total uncompressed-size caps (cursor) - Reject decompress input that resolves to more than one archive with a clear error instead of silently extracting only the first (cursor)

waleedlatif1 · 2026-06-16T19:00:34Z

@greptile

waleedlatif1 · 2026-06-16T19:00:35Z

@cursor review

The block already rejects multiple archives, but the manage route is the real boundary (callable directly and by the LLM tool) and still took the first of multiple resolved inputs. Add the empty-input and >1-archive guards in the route so extra archives are rejected with a clear error rather than silently ignored (cursor).

waleedlatif1 · 2026-06-16T19:06:28Z

@greptile

waleedlatif1 · 2026-06-16T19:06:29Z

@cursor review

cursor

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit 128a80a. Configure here.}

…nces - Drop the misleading 'under provider upload limits' claim from the compress tool description (models cannot read zip archives) - Fix bestPractices to reference the 'files' output, not a non-existent 'file' - Remove the stale 'file' property from the compress test fixture so it matches the real API response (greptile)

waleedlatif1 · 2026-06-16T19:13:40Z

Addressed the three doc/test accuracy findings from the latest review in cdf521b:

Removed the misleading "under provider upload limits" claim from the file_compress description (models can't read zip archives).
Fixed the block bestPractices to reference the files output instead of a non-existent file output.
Removed the stale file property from the compress test fixture so it matches the real API response.

No runtime behavior changed.

waleedlatif1 · 2026-06-16T19:13:41Z

@greptile

waleedlatif1 · 2026-06-16T19:13:42Z

@cursor review

cursor

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit cdf521b. Configure here.}

feat(file): add Compress operation to bundle files into a .zip archive

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waleedlatif1 changed the title ~~feat(file): add Compress operation to bundle files into a .zip archive~~ feat(file): add Compress and Decompress operations to the File block Jun 16, 2026

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waleedlatif1 merged commit f238184 into staging Jun 16, 2026
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waleedlatif1 deleted the perf/file-compress branch June 16, 2026 19:25

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Summary

Safety

Note

Type of Change

Testing

Checklist

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PR Summary

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Greptile Summary

Confidence Score: 5/5

Important Files Changed

Sequence Diagram

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