WPT
wpt / fs / FileSystemWritableFileStream-write.https.any.serviceworker.html
Spec: File System ↗
Runs: Chrome 155.0.8042.0 (wpt@0588f3896, 2026-09-04) | Firefox 157.0a1 (wpt@0588f3896, 2026-09-04) | Safari 251 preview (wpt@e7122b73f, 2026-09-04) | Ladybird 1.0-b1af2 (wpt@0588f3896, 2026-09-04) | Servo Servo 0.6 (wpt@2c385f65e, 2026-09-04) | Blitz a50cb8971 (wpt@a95401e4e, 2026-09-03)
View on the Blitz WPT dashboard | Open test on wpt.live | wpt.fyi
| Chrome | Firefox | Safari | Ladybird | Servo | Blitz | |
|---|---|---|---|---|---|---|
| Total | 31/31 | 31/31 | 31/31 | 0/31 | 0/31 | NOT RUN |
| Subtest | Chrome | Firefox | Safari | Ladybird | Servo | Blitz |
|---|---|---|---|---|---|---|
| write() with an empty blob to an empty file | PASS | PASS | PASS | — | — | — |
| write() a blob to an empty file | PASS | PASS | PASS | — | — | — |
| write() with WriteParams without position to an empty file | PASS | PASS | PASS | — | — | — |
| write() a string to an empty file with zero offset | PASS | PASS | PASS | — | — | — |
| write() a blob to an empty file with zero offset | PASS | PASS | PASS | — | — | — |
| write() called consecutively appends | PASS | PASS | PASS | — | — | — |
| write() WriteParams without position and string appends | PASS | PASS | PASS | — | — | — |
| write() WriteParams without position and blob appends | PASS | PASS | PASS | — | — | — |
| write() called with a string and a valid offset | PASS | PASS | PASS | — | — | — |
| write() called with a string and a valid offset after seek | PASS | PASS | PASS | — | — | — |
| write() called with a blob and a valid offset | PASS | PASS | PASS | — | — | — |
| write() called with an offset beyond the end of the file | PASS | PASS | PASS | — | — | — |
| write() with an empty string to an empty file | PASS | PASS | PASS | — | — | — |
| write() with a valid utf-8 string | PASS | PASS | PASS | — | — | — |
| write() with a string with unix line ending preserved | PASS | PASS | PASS | — | — | — |
| write() with a string with windows line ending preserved | PASS | PASS | PASS | — | — | — |
| write() with an empty array buffer to an empty file | PASS | PASS | PASS | — | — | — |
| write() with a valid typed array buffer | PASS | PASS | PASS | — | — | — |
| atomic writes: writable file streams make atomic changes on close | PASS | PASS | PASS | — | — | — |
| atomic writes: write() after close() fails | PASS | PASS | PASS | — | — | — |
| atomic writes: truncate() after close() fails | PASS | PASS | PASS | — | — | — |
| atomic writes: close() after close() fails | PASS | PASS | PASS | — | — | — |
| atomic writes: only one close() operation may succeed | PASS | PASS | PASS | — | — | — |
| getWriter() can be used | PASS | PASS | PASS | — | — | — |
| WriteParams: truncate missing size param | PASS | PASS | PASS | — | — | — |
| WriteParams: write missing data param | PASS | PASS | PASS | — | — | — |
| WriteParams: write null data param | PASS | PASS | PASS | — | — | — |
| WriteParams: seek missing position param | PASS | PASS | PASS | — | — | — |
| write() with an invalid blob to an empty file should reject | PASS | PASS | PASS | — | — | — |
| an errored writable stream releases its lock | PASS | PASS | PASS | — | — | — |
| an errored writable stream should reject the next write call | PASS | PASS | PASS | — | — | — |