jason810496 opened a new pull request, #73443: URL: https://github.com/apache/airflow/pull/73443
# TS SDK: add conditional branching with dag.if - **Depends on the PR for `feature/ts-sdk/answer-dag-parse-request` getting merged first** (only the last commit is new here). - **Diff for early review**: https://github.com/jason810496/airflow/compare/feature/ts-sdk/answer-dag-parse-request...feature/ts-sdk/conditional-branching - **next**: `feature/ts-sdk/multi-way-branching` ## Why `airflow-core/adr/lang-sdk/0008-control-flow-constructs.md` names each construct after the host language's control flow. This is TypeScript's `if`/`else`. ## How - `dag.if(taskId, condition, branches)` registers an ordinary task returning a boolean, plus the task each outcome follows. - Nothing about the branch reaches the Dag JSON. The control edges serialize as ordinary order-only edges, and which side a run takes is a run-time skip the SDK sends, so a guarded task takes no parameter for the control edge. - A one-sided `if` is a branch with a single candidate, per decisions 1 and 3 of that ADR: it skips `then` and follows nothing, rather than short-circuiting the whole downstream closure. The branches travel in an options object rather than `gate.then(...)` chaining, which is the one place TypeScript has to differ from the Go spelling: an object with a callable `then` is a thenable, so a gate reaching an `await` would be resolved as a promise. Recorded in `ts-sdk/adr/0002`. ## What - `dag.if` and the `Branches` type. - `skipDownstreamTasks` on the task client, the mechanism Python reaches through `skip()` and `skip_all_except()`. Needs the core side to honour `SkipDownstreamTasks` from a non-Python runtime. --- ##### Was generative AI tooling used to co-author this PR? - [x] Yes, with help of Claude Code Opus 5 following [the guidelines](https://github.com/apache/airflow/blob/main/contributing-docs/05_pull_requests.rst#gen-ai-assisted-contributions) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
