formData(): read a file- or S3-backed Blob body before parsing it by robobun · Pull Request #45161 · oven-sh/bun

robobun · 2026-10-13T13:54:02Z

Problem

formData() on a Response or Request over Bun.file() resolves an empty FormData and never reads the file. Node parses the same body from fs.openAsBlob().
A multipart file rejects with FormData parse error missing final boundary. Bun.file(p).stream() as the body parsed in 1.3 and is empty since 1.4.0.
Cause: get_form_data (src/runtime/webcore/Body.rs:2130) parses blob.slice() at once. That slice is empty when the bytes are on disk or in S3.

Fix

After the Content-Type check, FormDataBodyRead takes a Blob whose bytes are on disk or in S3. It reads them off the JS thread, then parses.
A read failure rejects as text() does (ENOENT, EISDIR). A parse failure keeps ERR_FORMDATA_PARSE_ERROR.
Verified: test/js/web/html/FormData.test.ts (33 new cases, all fail on a debug build of main). Also the body, image and s3 suites.
Self-reviewed: 17 concerns raised, 17 addressed.

Background

A Bun.file() is a Blob with a lazy store: a path, a file descriptor, or an S3 key.
read_bytes_to_handler (Blob.rs) reads any store and hands over an owned buffer. Bun.Image was its only user.
Considered Blob::to_form_data (8da2c60 in Take the native blob path for Response-wrapped Bun.file() streams #31674): it rejects with a plain Error. Considered a stream: it reads on the JS thread.

Downsides

Behavior change: formData() on these bodies waits for the read and can reject.
Bodies in memory: -2 to +3 instructions per call, no added allocations or syscalls. Release .text: +3,840 B.
Still wrong: FormData.from(Bun.file(p)) is empty. An S3 read failure has name: "Error", not S3Error.

Notes

Where this came from. No user reported it. It was found during the work on #44999. There is no issue for it.

Repro. The file holds a=1&b=2.

const type = "application/x-www-form-urlencoded";
await new Response(Bun.file(p, { type })).formData(); // main: {}   here: { a: "1", b: "2" }
await new Response(Bun.file(p), { headers: { "content-type": type } }).formData(); // main: {}
await new Request("http://a/", { method: "POST", body: Bun.file(p, { type }) }).formData(); // main: {}
await new Response(await fs.openAsBlob(p, { type })).formData(); // main: {}   node v26.3.0: { a: "1", b: "2" }

History, from released binaries ([] is an empty FormData):

`formData()` of	1.1.0	1.2.0	1.3.0	1.4.0	1.4.2	main	here
`new Response(Bun.file(p), { headers })`	`[]`	`[]`	`[]`	`[]`	`[]`	`[]`	parsed
`new Response(Bun.file(p), { headers })` after `.body` was read	parsed	`[]`	`[]`	`[]`	`[]`	`[]`	parsed
`new Response(Bun.file(p).stream(), { headers })`	parsed	`[]`	parsed	`[]`	`[]`	`[]`	parsed
a `clone()` of that	one side	`[]`	parsed	parsed	parsed	`[]`	parsed
`new Response(Bun.stdin.stream(), { headers })`, stdin a pipe			parsed	`[]`	`[]`	`[]`	parsed

The direct Bun.file() body never parsed. The parse of blob.slice() dates from aa0762e (Implement FormData #2051).
The stream forms changed with the lift of an unread file stream back into its Blob. 289f532 (Body: downgrade the .body getter's Strong<ReadableStream> once the wrapper's traced slot owns it #36624) is first in 1.4.0 and b5ba14b (webcore: clone() keeps the Blob behind an unread native body stream instead of teeing it #42053) is first in 1.4.3. The lift stays: the other readers need it, and they check where the bytes are. formData() was the one reader that did not.

Workaround on a released version. new Response(await r.arrayBuffer(), { headers: r.headers }).formData().

The change. Body.rs only, +83 -6. The gate is the if let AnyBlob::Blob(source) = &blob && (source.needs_to_read_file() || source.is_s3()) after use_as_any_blob(). The Content-Type decision and the stream (Locked) branch above it are as before, so a wrong type still rejects before anything is read. FormDataBodyRead owns the promise and the encoding. read_bytes_to_handler gives it the bytes, or the error, on the JS thread.

Why not Blob::to_form_data. 8da2c60 in #31674 put the same gate here and sent the body to the Blob method. That PR has conflicts and no push since 2026-06-10. This PR replaces that commit. The Blob method takes the encoding from the Blob's type, so the commit wrote the header's type onto the Blob first. A Blob type is lower case, and a boundary is not. The Blob method also rejects a parse failure with a plain Error, and on main it does not free its read buffer (#44888 and 675d347 in #31674 each fix that, neither is merged).

What formData() reads now. One gate covers each way to a file or S3 Blob body:

Bun.file(path), Bun.file(fd), Bun.stdin, a slice, fs.openAsBlob(), new Blob([file]).
A Request whose body is s3.file(key). new Response(s3File) is a redirect and has no body.
.body read first, Bun.file(p).stream() as the body, and a clone() of each.
The Response of fetch("file://...") and of fetch(URL.createObjectURL(file)). The second one is also how a Response gets an S3 body.

Not fixed here.

The class. Blob::shared_view() and Any::slice() are empty for a file or S3 store. Other APIs read such a Blob as zero bytes: Bun.hash(file) equals Bun.hash(""), and new Blob([file, "x"]).size is 1. formData() lands alone because it already returns a promise and its four sibling readers already read. The others are synchronous and need a decision: read or throw. Blob: read file-backed parts in multi-part new Blob([...]) #33600, redis: reject file-backed Blob arguments instead of sending the empty string #36836, Throw DataCloneError when structured-cloning an S3File #37905, FormData: throw when serializing an S3-backed entry instead of sending an empty part #38364, WebSocket client: throw on file- or S3-backed Blobs in send(), ping() and pong() instead of sending an empty frame #39082 and Bun.Archive: read Bun.file() input from disk instead of writing empty bytes #41193 each take one site.
FormData.from(Bun.file(p)) returns an empty FormData with no error (FormData.rs:137). It is synchronous, so its fix is a throw. That is a behavior change on another public function.
Value::resolve's GetFormData arm (Body.rs:1146) has the same synchronous parse. Its four callers pass bytes in memory, so it cannot see a file.
.body read first when only Bun.file(p, { type }) carries the form type still rejects with incorrect MIME type/boundary. The type check runs before the read that this PR adds. That is a separate bug. Response: keep the body-derived Content-Type when the body is read before the headers #42015 and Request: take the Content-Type from the body init at construction, not from a stream's source #42217 are open for the Content-Type of a body that was read first.
A parse failure still has three other shapes elsewhere: Error "FormData X" for a pending fetch or Bun.serve body, Error "X while parsing FormData" for a JS stream body, and Error "FormData encoding failed: X" for Blob.formData(). This PR matches the shape of a body in memory.
An S3 read failure rejects with { name: "Error", code: "NoSuchKey", message, path, syscall: "fetch" }. text() rejects with { name: "S3Error", code, message, path }. Code, message and path are equal. read_bytes_to_handler flattens the failure for each of its users (Blob.rs:574), and Bun.Image ships the same shape. A new ReadBytesResult arm would keep the name, but Implement the async Clipboard API (navigator.clipboard) #33312 matches that enum with two arms, so the arm would break its build.

Self-review. The review asked for these changes, and each one is in:

Keep the source change in one file. An S3 failure keeps the shape that read_bytes_to_handler gives it, and ReadBytesResult gets no new arm (see the last bullet above).
No JSPromise::wrap around the start of the read, and no bytes.is_empty() clause in the gate. No test needed either one.
Tests for a pipe on stdin, fetch() of a blob: URL (file and S3), a clone() of a stream body, the async stack of a read failure, and Bun.gc(true) while the read is pending. A later case covers bytes over the string limit: a file body and the same bytes in memory both reject with ERR_STRING_TOO_LONG.
A faster Worker case (about 1 s on a debug build). It stays in FormData.test.ts and is not a row in worker-late-completion.test.ts. On a 12-core machine the rows of that file time out under bun bd test at the default 5 s.
Name each exclusion, and put the history in this text.

Measurements. Release builds of base 7c96a12 and of the first revision of this branch, linux x64. The later commits are a rebase, test changes, and one statement moved in the cold start.

In-memory formData(): -2 to +3 self instructions per call in get_form_data (Response string body 113 -> 114, Request string body 136 -> 137, Blob and URLSearchParams bodies +3. gdb nexti, pc inside the function). A body behind a stream and a pending Bun.serve body: +0 (131 -> 131, 154 -> 154, 123 -> 123).
In-memory formData(): +0 mi_malloc, +0 mi_free, +0 promises, +0 syscalls per call (13 / 7 for a string body on both builds).
Release binary: +3,840 B .text (65,818,341 -> 65,822,181). get_form_data 1,376 / 1,732 B -> 1,347 / 1,710 B. New cold symbols 3,061 B. read_bytes_to_handler instantiations 1 -> 2 (1,005 B).
Host functions +0, codegen rows +0, .d.ts lines +0.
File-body formData(): 1 openat / 1 fstat / 2 read / 1 close per call, 0 on the JS thread (text(): 1 / 1 / 2 / 1, 0). A ptrace counter over 1,000 calls, strace is not installed here.
File-body formData(): 1 Promise, 0 ReadableStream per pending call (text(): 1, 0). 3 mi_malloc in the call (text(): 2).
S3 Request body: 1 GET per formData() call (0 on the base). Range header on an unsliced body: none. A slice sends bytes=5-20.
LeakSanitizer on FormData.test.ts: 0 leak reports, exit 0. RSS over 40 x 8 MiB: formData() 43 -> 44 MB, text() 33 -> 34 MB.
Fields that differ from text(): ENOENT 0, EISDIR 0, NoSuchKey 2, S3 sign failure 2 (name and syscall, see above). From the in-memory parse error: 0.
Bun.Image S3 read failure: 0 of 5 fields changed. This PR does not touch that code.
Worker teardown with a pending formData() read: exit 0, sanitizer reports 0.
+3 lines with unsafe, +0 cfg arms. bun run rust:check-all: 0 errors across 12 targets. The tests ran on linux x64 only.

Suites, debug build:

FormData.test.ts: 182 pass. On main 149 pass and the 33 new cases fail. A release build skips the Worker case, which needs a debug or ASAN build.
The same file with BUN_JSC_validateExceptionChecks=1 and LeakSanitizer: 182 pass.
body.test.ts: 774 pass. Two "string body consumption does not leak" json cases time out at 5 s, on main too. The release build passes all 776.
body-clone 100, body-mixin-errors 23, client-fetch 34, image 103, s3 307, body-stream 9086.
streams.test.js: 604 to 624 of 624. The Bun.spawn({ stdin }) cases of "direct stream contract" time out at 5 s in some runs, on main too (616 to 623 there).

Open PRs on the same lines. #44999 and #44969 change get_form_data above the gate, and #44999 adds tests to the same file. #40221 changes ReadBytesHandler::on_read_bytes to take self: Box<Self>. The second PR to land needs a small rebase.

[human-review] gate passed · iteration 0 · 2 files touched

fails on main (without fix)

ASAN without fix: 33 FAILED
$ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/pr_gate.xml" test/js/web/html/FormData.test.ts
bun test v1.4.4 (367d939d9)

test/js/web/html/FormData.test.ts:
(pass) FormData > should be able to append a string [3.68ms]
(pass) FormData > should be able to append a Blob [14.45ms]
(pass) FormData > should be able to set a Blob [6.32ms]
(pass) FormData > should be able to set a string [3.08ms]
(pass) FormData > should get filename from file [3.73ms]
(pass) FormData > should use the correct filenames [4.46ms]
(pass) FormData > should parse multipart/form-data (simple) with Response [13.56ms]
(pass) FormData > should roundtrip multipart/form-data (simple) with Response [33.10ms]
(pass) FormData > should parse multipart/form-data (simple) with Request [4.15ms]
(pass) FormData > should roundtrip multipart/form-data (simple) with Request [9.85ms]
(pass) FormData > should parse multipart/form-data (simple with trailing CRLF) with Response [1.46ms]
(pass) FormData > should roundtrip multipart/form-data (simple with trailing CRLF) with Response [2.55ms]
(pass) FormData > should parse multipart/form-data (si
... (truncated)

release without fix: 32 failed, 1 skipped
bun test v1.4.3-canary.1 (367d939d9)

test/js/web/html/FormData.test.ts:
(pass) FormData > should be able to append a string [0.13ms]
(pass) FormData > should be able to append a Blob [0.46ms]
(pass) FormData > should be able to set a Blob [0.12ms]
(pass) FormData > should be able to set a string [0.07ms]
(pass) FormData > should get filename from file [4.31ms]
(pass) FormData > should use the correct filenames [0.13ms]
(pass) FormData > should parse multipart/form-data (simple) with Response [5.96ms]
(pass) FormData > should roundtrip multipart/form-data (simple) with Response [13.72ms]
(pass) FormData > should parse multipart/form-data (simple) with Request [0.13ms]
(pass) FormData > should roundtrip multipart/form-data (simple) with Request [0.06ms]
(pass) FormData > should parse multipart/form-data (simple with trailing CRLF) with Response [0.01ms]
(pass) FormData > should roundtrip multipart/form-data (simple with trailing CRLF) with Response [0.02ms]
(pass) FormData > should parse multipart/form-data (simple with trailing CRLF) with Request
(pass) FormData > should roundtrip multipart/form-data (simple with trailing CRLF) with Request [0.01ms]
(pass) FormData 
... (truncated)

passes on PR (with fix)

ASAN with fix: all passed
$ BUN_DEBUG_QUIET_LOGS=1 bun scripts/build.ts --profile=debug --quiet test "--reporter=junit" "--reporter-outfile=/tmp/pr_gate.xml" test/js/web/html/FormData.test.ts
bun test v1.4.4 (367d939d9)

test/js/web/html/FormData.test.ts:
(pass) FormData > should be able to append a string [22.97ms]
(pass) FormData > should be able to append a Blob [12.72ms]
(pass) FormData > should be able to set a Blob [6.27ms]
(pass) FormData > should be able to set a string [2.51ms]
(pass) FormData > should get filename from file [5.39ms]
(pass) FormData > should use the correct filenames [5.00ms]
(pass) FormData > should parse multipart/form-data (simple) with Response [15.97ms]
(pass) FormData > should roundtrip multipart/form-data (simple) with Response [33.06ms]
(pass) FormData > should parse multipart/form-data (simple) with Request [4.35ms]
(pass) FormData > should roundtrip multipart/form-data (simple) with Request [4.48ms]
(pass) FormData > should parse multipart/form-data (simple with trailing CRLF) with Response [1.46ms]
(pass) FormData > should roundtrip multipart/form-data (simple with trailing CRLF) with Response [2.28ms]
(pass) FormData > should parse multipart/form-data (s
... (truncated)

release with fix: 1 skipped
$ bun scripts/build.ts --profile=release
[configured] bun-profile → bun (stripped)
  target       linux-x64-gnu
  build type   Release
  build dir    ./build/release
  revision     f260d7b834
  features     lto, baseline

23 deps, 146 codegen, 1179 objects in 5646ms

ninja: Entering directory `/workspace/bun/build/release'
[1/4] fetch lolhtml
[lolhtml] up to date
[2/4] fetch rust-argon2
[rust-argon2] up to date
[2/4] cargo plan → /workspace/bun/build/release/rust-target/plan.json
264 units: 192 lib, 16 proc-macro (host), 19 custom-build (host), 15 run custom-build, 17 lib (host), 4 run custom-build (host), 1 rlib
[3/4] reconfigure
[1/1531] mkdir stamps
[2/1531] mkdir codegen
[3/1531] gen bake.{client,server,error}.js
-> bake.client.js, bake.server.js, bake.error.js
[4/1531] install /workspace/bun
bun install v1.4.3-canary.1 (367d939d9)

Checked 22 installs across 44 packages (no changes) [1032.00ms]
[5/1531] install /workspace/bun/packages/bun-error
bun install v1.4.3-canary.1 (367d939d9)

Checked 1 install across 2 packages (no changes) [46.00ms]
[6/1531] install /workspace/bun/src/node-fallbacks
bun install v1.4.3-canary.1 (367d939d9)

Checked 111 installs acr
... (truncated)

diff hotspot

src/runtime/webcore/Body.rs       |  89 ++++++++-
 test/js/web/html/FormData.test.ts | 401 +++++++++++++++++++++++++++++++++++++-
 2 files changed, 483 insertions(+), 7 deletions(-)

gate history · 1 passed · 0 rejected · iteration 0

evidence per changed file

file                               reads  edits  tests
src/runtime/webcore/Body.rs            3      4     50
test/js/web/html/FormData.test.ts      4      1     49

robobun · 2026-10-13T13:54:16Z

^{Updated 9:50 AM PT - Oct 16th, 2026}

✅ @robobun, your commit f260d7b834cdea347739842ba48cd9dd633f3675 passed in Build #126726! 🎉

🧪 To try this PR locally:

bunx bun-pr 45161

That installs a local version of the PR into your bun-45161 executable, so you can run:

bun-45161 --bun

robobun · 2026-10-13T13:56:35Z

Reproduced on the released 1.4.2 and 1.4.3 builds and on a build of main with this program. The file holds a=1&b=2.

import fs from "node:fs";
const type = "application/x-www-form-urlencoded";
const list = async body => JSON.stringify([...(await body.formData())]);
console.log(await list(new Response(Bun.file(p, { type }))));
console.log(await list(new Response(Bun.file(p), { headers: { "content-type": type } })));
console.log(await list(new Request("http://a/", { method: "POST", body: Bun.file(p, { type }) })));
console.log(await list(new Response(await fs.openAsBlob(p, { type }))));

1.4.2, 1.4.3, main   []  []  []  []
this branch          [["a","1"],["b","2"]] on each line
node v26.3.0         [["a","1"],["b","2"]] for the openAsBlob line

The new cases in test/js/web/html/FormData.test.ts fail on main (33 on a debug build, 32 on a release build that skips the debug-only case) and pass on this branch.

coderabbitai · 2026-10-13T13:57:59Z

No actionable comments were generated in the recent review. 🎉

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src/runtime/webcore/Body.rs

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Walkthrough

get_form_data now reads file-backed and S3 Blob bodies asynchronously before parsing. Parse failures use a shared error construction. Read failures reject with an error that carries the async stack.

Changes

Asynchronous FormData Parsing

Layer / File(s)	Summary
Blob reads and FormData parsing `src/runtime/webcore/Body.rs`	`get_form_data` starts asynchronous reads for file-backed and S3 Blob bodies. The read callback parses the bytes and settles the promise with FormData or an error.
File and S3 body source coverage `test/js/web/html/FormData.test.ts`	Tests cover multipart and URL-encoded parsing from file-backed, stream, cloned, blob URL, and S3 bodies.
Errors and pending-read behavior `test/js/web/html/FormData.test.ts`	Tests cover body consumption during pending reads, read and parse failures, garbage collection, string-length limits, and worker teardown during a file read.

Suggested reviewers: jarred-sumner, dylan-conway

Priority: ➖ Normal

Merge Risk: ⚪ Minimal · up to f260d

The change enables parsing file- and S3-backed FormData bodies after their bytes are read. The reviewed worker-teardown path is safe, and no actionable merge-blocking risk remains.

Pre-merge checks: 4

Check name	Status	Explanation
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.
Title check		The title clearly and concisely summarizes the main change: reading file- or S3-backed Blob bodies before parsing them with formData().
Description check		The description explains the problem, fix, scope, known limitations, and verification results. It does not use the exact template headings, but it provides the required change summary and testing info…

Full details: Description check

Explanation

The description explains the problem, fix, scope, known limitations, and verification results. It does not use the exact template headings, but it provides the required change summary and testing information in detail.

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coderabbitai

Actionable comments posted: 1

🪄 Fix CodeRabbit comments on this PR

🤖 Prompt to fix review comments

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Inline comments:
Review comments at @test/js/web/html/FormData.test.ts:
- Line 783: Update the file-backed test block using owners from describe.each to
describe.concurrent.each, keeping its existing test cases and setup unchanged.

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src/runtime/webcore/Body.rs
test/js/web/html/FormData.test.ts

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claude

Nothing blocking. The comments below are optional suggestions. There is no need to push a fix for them before merging.

Beyond the inline findings, I also checked two things in the new FormDataBodyRead path and found them sound: the leaked Box is handed back exactly once on every terminal path (Blob.rs read_bytes_to_handler delivers synchronously before returning Err, and the file-read cancel arm delivers an ECANCELED result at teardown), and a parse failure returned as Ok(error_instance) inside AnyPromise::wrap does reject rather than resolve, because JSC__AnyPromise__wrap in bindings.cpp rejects on an ErrorInstance result.

Extended reasoning...

The change is confined to src/runtime/webcore/Body.rs (an async read branch in get_form_data plus a ReadBytesHandler impl) and a new test block in test/js/web/html/FormData.test.ts; it touches no auth, crypto or injection surface. Three confirmed findings are posted inline, so a human look is already signalled; this note only records the ownership and promise-settlement concerns that were examined and ruled out.

Additional findings (outside the current diff — GitHub can't attach inline comments there):

🟣 src/runtime/webcore/Body.rs — Users who read .body first on a Response built from Bun.file(p, { type }) still get a rejection "Can't decode form data from body because of incorrect MIME type/boundary" from formData(), while the PR's table says the body-read-first row now parses. The type check at src/runtime/webcore/Body.rs:2092-2102 runs before the new read at Body.rs:2131, and after to_blob_if_possible at Body.rs:2078/2088 the lifted Blob's type is not consulted when the owner has no Content-Type header. Fix: when the owner has no Content-Type header, derive the form encoding from the lifted Blob's type (the same source the direct Bun.file body uses) before rejecting, covering both the .body and the clone() forms.

Why this was flagged

Trigger: const r = new Response(Bun.file(p, { type: "application/x-www-form-urlencoded" })); r.body; await r.formData(). Entry is get_form_data at Body.rs:2058; the Locked branch lifts the stream back into a Blob at Body.rs:2078/2088, then get_form_data_encoding at Body.rs:2092 looks only at the owner's headers and rejects at Body.rs:2094-2101 before the new file read at Body.rs:2131 can run. The base rejected the same way, but the base also never read the file at all; this PR adds the read for the direct form and the PR text lists 'the same after .body was read' as parsed, so users following that row hit the rejection. The direct form with no headers works because get_form_data_encoding falls back to the Blob's type when the value is a Blob; the lifted Blob after .body takes the Locked path where that fallback is not reached. Remedy: run the lift before the encoding decision, or have get_form_data_encoding consult the lifted Blob's type, so the sibling .body-first and clone() forms parse like the direct one.

Verification: Pre-existing: the base branch rejects it by the same route; the PR lists it under "Not fixed here". Trigger: new Response(Bun.file(p, { type: "application/x-www-form-urlencoded" })) with no headers, then r.body, then r.formData(). The lift rebuilds the Blob from the store, losing the user-set type (ReadableStream.rs:216), so Body.rs:2092-2102 rejects before the read at Body.rs:2131.

formData() on a Response or Request whose body is a Bun.file() parsed blob.slice() at once. That slice is empty until the file is read, so the call resolved an empty FormData and never opened the file. get_form_data now hands a Blob whose bytes are on disk or in S3 to a read_bytes_to_handler consumer. It reads the bytes off the JS thread, parses them with the encoding that the call decided, and settles the promise. A read failure rejects as text() does. A parse failure keeps ERR_FORMDATA_PARSE_ERROR.

The S3 case used a 2000-byte key as a key that cannot be signed. macOS refuses a path of that length before the request is signed, so s3.file() threw ENAMETOOLONG there. The key is now 600 "+" bytes. It fits the path limit of every platform and does not fit the signed URL. The cases share no state, so the block is concurrent. A new case covers bytes over the string limit, in a process of its own.

claude

Code review found no issues

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Unresolved: 2 minor or pre-existing.

The order of the two statements no longer needs a comment. The doc comment of FormDataBodyRead is one line.

robobun · 2026-10-16T15:29:31Z

On the additional finding of the review from 2026-10-13 (.body read first, with the form type only on Bun.file(p, { type })):

That case still rejects with incorrect MIME type/boundary, on main and on this branch. The Content-Type decision runs before the read that this PR adds, and it does not see the type of the lifted Blob. This PR does not change that decision.
The history table suggested that the case parses. The row now reads "new Response(Bun.file(p), { headers }) after .body was read", which is the case that parses.
The case is under "Not fixed here" in the PR text. Response: keep the body-derived Content-Type when the body is read before the headers #42015 and Request: take the Content-Type from the body init at construction, not from a stream's source #42217 are open for the Content-Type of a body that was read first.

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github-actions Bot added the claude label Oct 13, 2026

robobun mentioned this pull request Oct 13, 2026

Take the native blob path for Response-wrapped Bun.file() streams #31674

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coderabbitai Bot reviewed Oct 13, 2026

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Comment thread test/js/web/html/FormData.test.ts

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Comment thread src/runtime/webcore/Body.rs

Comment thread src/runtime/webcore/Body.rs

robobun added 2 commits October 16, 2026 14:52

robobun force-pushed the robobun/e086f7d3/formdata-file-backed-body branch from a4b2e70 to 39e081b Compare October 16, 2026 15:10

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Comment thread src/runtime/webcore/Body.rs Outdated

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Comment thread src/runtime/webcore/Body.rs Outdated

claude Bot reviewed Oct 16, 2026

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formData(): take the promise value before FormDataBodyRead is boxed

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The order of the two statements no longer needs a comment. The doc comment of FormDataBodyRead is one line.

claude Bot reviewed Oct 16, 2026

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formData(): read a file- or S3-backed Blob body before parsing it - #45161

formData(): read a file- or S3-backed Blob body before parsing it#45161
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