Fix #62414: Remove spurious blank lines in filtered task log download by bennyc0de · Pull Request #64235 · apache/airflow

bennyc0de · 2026-03-25T23:22:42Z

Problem

When a log level or source filter was active in the Task Instance Logs view, downloading the logs produced an empty or nearly-empty file.

The root cause: renderStructuredLog returns an empty string ("") for each log line that doesn't match the active filter. The getLogString function in Logs.tsx was joining all parsed lines with "\n" — including those empty strings. This meant that if filtered-out lines appeared at the start (or throughout) the log, the downloaded file would be filled with blank lines, or appear empty when all lines were filtered out.

Solution

Filter out empty strings before joining:

const getLogString = () => getParsedLogs().join("\n");

const getLogString = () => getParsedLogs().filter((line) => line !== "").join("\n");
This ensures the downloaded file contains only lines that passed the active filter, with no spurious blank lines. A new test file logDownloadContent.test.ts covers the key cases: all lines filtered out, no leading newlines when early lines are excluded, and correct inclusion of lines that match the filter.
Closes: Logs downloaded as empty file when filtering by log level #62414

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Generated-by: [Claude Sonnet 4.6] following the guidelines

boring-cyborg · 2026-03-25T23:22:44Z

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bbovenzi · 2026-03-26T17:40:43Z

Can you please update the PR description with the problem and solution? Ideally with screenshots. Also, tag the relevant github issue if there is one

bennyc0de · 2026-03-26T21:31:06Z

Can you please update the PR description with the problem and solution? Ideally with screenshots. Also, tag the relevant github issue if there is one

Hi, sorry about that I had accidentally commented out the body of the description. Now you have an explanation and some screenshots detailing the problem and fix.

…wnload When log level or source filters were applied, renderStructuredLog returned empty strings for dropped lines. Joining those with newlines still inserted blank lines, often at the start of the downloaded file.

Reformats getLogString arrow function to stay within line length limit, and fixes object key ordering (content before continuation_token) in test fixtures to match Prettier's alphabetical sorting.

bennyc0de · 2026-03-31T22:32:03Z

Hi @bbovenzi — the Helm, PROD image, and Kubernetes CI jobs are failing on this PR, but my changes are limited to Logs.tsx (a frontend TypeScript file). The failures don't reproduce locally and appear unrelated to the change. Could you re-trigger them, or let me know if there's something I'm missing?

Copilot

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

pierrejeambrun

Nice thanks

boring-cyborg · 2026-04-02T18:47:42Z

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.

…log download (#64235) * Fix #62414: Remove spurious blank lines in filtered task log download When log level or source filters were applied, renderStructuredLog returned empty strings for dropped lines. Joining those with newlines still inserted blank lines, often at the start of the downloaded file. * Fix prek formatting in Logs.tsx and logDownloadContent.test.ts Reformats getLogString arrow function to stay within line length limit, and fixes object key ordering (content before continuation_token) in test fixtures to match Prettier's alphabetical sorting. (cherry picked from commit 32ac564) Co-authored-by: Bernardo Gunzburger Lopes <130933290+bennyc0de@users.noreply.github.com>

github-actions · 2026-04-02T18:48:56Z

Backport successfully created: v3-2-test

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

In matter of doubt please ask in #release-management Slack channel.

Status	Branch	Result
✅	v3-2-test

… task log download (apache#64235) * Fix apache#62414: Remove spurious blank lines in filtered task log download When log level or source filters were applied, renderStructuredLog returned empty strings for dropped lines. Joining those with newlines still inserted blank lines, often at the start of the downloaded file. * Fix prek formatting in Logs.tsx and logDownloadContent.test.ts Reformats getLogString arrow function to stay within line length limit, and fixes object key ordering (content before continuation_token) in test fixtures to match Prettier's alphabetical sorting. (cherry picked from commit 32ac564) Co-authored-by: Bernardo Gunzburger Lopes <130933290+bennyc0de@users.noreply.github.com>

…log download (#64235) (#64640) * Fix #62414: Remove spurious blank lines in filtered task log download When log level or source filters were applied, renderStructuredLog returned empty strings for dropped lines. Joining those with newlines still inserted blank lines, often at the start of the downloaded file. * Fix prek formatting in Logs.tsx and logDownloadContent.test.ts Reformats getLogString arrow function to stay within line length limit, and fixes object key ordering (content before continuation_token) in test fixtures to match Prettier's alphabetical sorting. (cherry picked from commit 32ac564) Co-authored-by: Bernardo Gunzburger Lopes <130933290+bennyc0de@users.noreply.github.com>

bennyc0de requested review from bbovenzi, choo121600, guan404ming, pierrejeambrun, ryanahamilton, shubhamraj-git and vatsrahul1001 as code owners March 25, 2026 23:22

boring-cyborg Bot added the area:UI Related to UI/UX. For Frontend Developers. label Mar 25, 2026

bennyc0de and others added 2 commits March 30, 2026 22:17

Fix prek formatting in Logs.tsx and logDownloadContent.test.ts

ef88733

Reformats getLogString arrow function to stay within line length limit, and fixes object key ordering (content before continuation_token) in test fixtures to match Prettier's alphabetical sorting.

bennyc0de force-pushed the main branch from 643c8f1 to ef88733 Compare March 30, 2026 21:29

bennyc0de added 2 commits March 30, 2026 22:40

Merge branch 'main' into main

05e4707

Merge branch 'apache:main' into main

29a0e6c

kaxil requested a review from Copilot April 2, 2026 00:43

Copilot AI reviewed Apr 2, 2026

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pierrejeambrun approved these changes Apr 2, 2026

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pierrejeambrun added the backport-to-v3-2-test Mark PR with this label to backport to v3-2-test branch label Apr 2, 2026

pierrejeambrun added this to the Airflow 3.2.1 milestone Apr 2, 2026

bbovenzi approved these changes Apr 2, 2026

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bbovenzi merged commit 32ac564 into apache:main Apr 2, 2026
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Fix #62414: Remove spurious blank lines in filtered task log download#64235

Fix #62414: Remove spurious blank lines in filtered task log download#64235
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bennyc0de commented Mar 25, 2026 •

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