[finding] A `decision` branch with no `expression` key registers and validates clean, although `DecisionConditionSchema` declares it required and the executor throws on the source-less envelope

[objectstack-fleet]

Filed by the domain:spec seat 5 (session_01Sfe5YjBLwB9J3y8fvm2xq1, seat post #19357) from the out-of-scope findings of the #17493 dev (report 5811268231, class b). ⛔ Filed unassigned and unlabelled: routing and grading are triage's. ⛔ Not a claim.

The defect

A decision node's branch written without its predicate (conditions: [{ label: 'y' }]) is accepted at FlowSchema.parse, AutomationEngine.registerFlow and objectstack validate.

Read by this seat on main 3b5607019f:

• packages/spec/src/automation/schemaless-node-config.zod.ts:384 declares expression: z.string() on DecisionConditionSchema, so the key is required there.
• packages/spec/src/automation/flow-node-expression-paths.ts:286-291 says DecisionConditionSchema is never parsed against a node's open z.record config, and that decision publishes no descriptor configSchema.

Measured by the #17493 dev (report 5811268231):

• { label: 'y' } is accepted at all three doors. Controls: 'true' is accepted, and ' ' is refused on the PR fix(spec)!: refuse a blank string in a flow node's predicate slot — decision branch expression, screen field visibleWhen (#17493) #19960 branch.
• evaluateCondition({ dialect: 'cel', source: undefined }) throws. That is the envelope the executor builds from such a branch.
• At the pinned objectui sha 62597c5880, FlowObjectListField rowsToList writes exactly { label } when the expression cell is blank.

The build therefore accepts a shape that the run time refuses.

Seam: spec:DecisionConditionSchema.expression → runtime: service-automation builtin/logic-nodes.ts decision executor | renderer: objectui FlowObjectListField rowsToList.

Dedupe words: decision branch expression absent · DecisionConditionSchema expression required not enforced · conditions label without expression · rowsToList drops blank cell · source-less envelope throws

[objectstack-fleet]

Blocked-by: #19960

分诊首次定级:priority:p2 · bug · domain:spec · pm:blocked —— 缺少 expression 的决策分支能通过构建,运行时才报错

Path: packages/spec/src/automation/flow.zod.ts(FlowSchema 的谓词槽精化)+ packages/spec/src/automation/flow-node-expression-paths.ts(predicateSlotRefusal)—— 两处都正被 PR #19960 修改

Triage: lands in the flow predicate-slot refusal ⇒ domain:spec, bug, priority:p2, pm:blocked Blocked-by #19960; rationale: DecisionConditionSchema declares expression required, but nothing parses a decision node's open config against it, so a branch with no expression passes FlowSchema.parse, registerFlow and objectstack validate and then throws in the executor — and objectui's Studio flow editor (FlowObjectListField rowsToList) writes exactly that shape when the expression cell is left blank (NORTH-STAR rule 4: wrong metadata must be refused at build time, with a remedy).

分诊席(session_01Tw7jnJinGHvoGSi8aFkhPJ,座位贴 #6015),2026-09-24T09:18Z。⛔ 不认领、不派发。本席读完了卡面(本卡尚无评论),并在 main(3b5607019f)和 objectui 62597c5 上核对了前提。

本席核对

• schemaless-node-config.zod.ts 里 DecisionConditionSchema 的 expression 是 z.string(),也就是必填。
• flow-node-expression-paths.ts:284-291 的注释写明:decision 没有发布 configSchema,DecisionConditionSchema 从不对节点的开放 config 做解析。所以这个"必填"没有任何地方在执行。
• objectui 的 packages/app-shell/src/views/metadata-admin/inspectors/FlowObjectListField.tsx:62 就是卡面说的 rowsToList。

定级说明

• p2:用户在 Studio 里给决策分支留空表达式,就能造出这种流程。保存和校验都会通过,流程运行到这个分支时才报错。这不是安全问题,也不会静默算错(运行时会报错),但报错太晚,作者(常常是 AI)在构建期拿不到任何提示。
• 同一类问题中的"空白字符串"情形,正由 PR fix(spec)!: refuse a blank string in a flow node's predicate slot — decision branch expression, screen field visibleWhen (#17493) #19960(spec/automation: three residues of #17322's node-door refusal — a stale on-site ruling, an ADR-0087 entry that names only the edge slot, and two sibling predicate slots still admitting a blank string #17493 裁定 A)在构建期拒绝。本卡是它相邻的"根本没有这个键"的情形。

为什么挂 pm:blocked

修复点就是 PR #19960 正在改的 FlowSchema 精化和 predicateSlotRefusal。在它合并之前另开 PR,会改同一个文件、同一段逻辑。⇒ Blocked-by #19960。PR #19960 合并后本卡立即可派发。PR #19960 已写明决策分支的处方是"删掉这个分支",本卡沿用。

方向(默认)

在同一个构建期拒绝里覆盖"缺少 expression"的决策分支,三道门(FlowSchema.parse、registerFlow、objectstack validate)都要报出同样的处方。objectui 编辑器那一侧不需要单独开卡:构建期拒绝上线后,编辑器保存时就会看到这条报错。

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Generated by Claude Code

[objectstack-fleet]

Unblock re-derivation: pm:blocked → pm:queue · 2026-09-24T23:58Z

Acting on the maintainer's instruction. Provenance: who — the maintainer; verbatim — 「帮我排查一下 blocked 卡片，哪些需要更新状态帮我更新。」; where — the maintainer's chat with session session_013RWUA7bNq5bRhehLPqXwMg, 2026-09-24. ⛔ Not a claim and not a dispatch: the card returns to its lane's take order. Candidate surfaced by check-half-states.mjs H19 on this sweep.

• Blocker: fix(spec)!: refuse a blank string in a flow node's predicate slot — decision branch expression, screen field visibleWhen (#17493) #19960 closed completed on 2026-09-24 (blank-string predicate refusal).
• Double-check ① — latest conversion comment 5811370954 names exactly that condition (same two files).
• Double-check ② — PR fix(spec)!: refuse a blank string in a flow node's predicate slot — decision branch expression, screen field visibleWhen (#17493) #19960 merged after that comment, but it is the named condition itself. It covers the blank-string case, not this card's absent-expression-key case, and it does not name [finding] A decision branch with no expression key registers and validates clean, although DecisionConditionSchema declares it required and the executor throws on the source-less envelope #19961. No commit on main does either.
• Re-derived, still owed: the absent-key arm of the decision-branch refusal.

State: pm:blocked → pm:queue; domain:spec, priority:p2 unchanged; no assignee.

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Generated by Claude Code

[objectstack-fleet]

Serial note from domain:spec seat 2 (session_01QcAS3qiYYZNezaxZxaUdMV), 2026-09-27T03:20Z. ⛔ Not a claim; the state is unchanged (pm:queue).

Passed over in this seat's round 1 because of a hot file. The fix lands in packages/spec/src/automation/flow-node-expression-paths.ts (predicateSlotRefusal) and flow.zod.ts. The first of those is named by the live claim on #19938 (seat 5, dispatched 2026-09-24, no open PR at this reading). Seat 1's #19867 holds the adjacent DecisionConfigSchema block in schemaless-node-config.zod.ts. Whoever takes this card re-reads both claims first. If #19938 has landed, merge main and build on its ledger shape.

[objectstack-fleet]

Claim: PM loop round 1 · 2026-09-27T16:51Z
Session: session_01Rjy9MeetSfq34PKn81CRiN
Account: os-zhuang
Branch: claude/issue-19961-decision-branch-expression-absent
Worktree: objectstack-issue-19961
Domain: domain:spec
Seat: domain:spec#1
File surface: packages/spec/src/automation/flow-node-expression-paths.ts (predicateSlotRefusal) and the FlowSchema predicate-slot refinement in packages/spec/src/automation/flow.zod.ts, with tests; one ADR-0087 semantic entry + packages/spec/src/migrations/registry.ts; generated artefacts; .changeset/. ⛔ Not schemaless-node-config.zod.ts's DecisionConfigSchema region or its mode refusal helper (seat 4's #20168); DecisionConditionSchema is read-only unless the refusal cannot live in the slot walk, which the dev must then report. (stop on breach; explain in the report)
Container & model: S, mode:subagent, model: default judgment tier (dispatch-gates --tier: no path-derived mandate, floor sonnet · default opus · ceiling fable). The diff hits packages/spec/src/**, so it is reviewed at CONTRACT_REVIEW_TIER before enqueue.
Clause-②: no
Thread-read: 5852253854
Serial constraints cleared: #19938 (PR #20205) has landed, so the hot file flow-node-expression-paths.ts is free; build on its ledger shape (seat 2's note 5852253854). Seat 4's #20168 (claim 5857419814) holds schemaless-node-config.zod.ts DecisionConfigSchema only and names this card as next and out of its surface; region-fenced above. No open PR touches flow-node-expression-paths.ts or automation/flow.zod.ts (15 open PRs' file lists read this act); PR #20258 (devx #12238) touches only the generated schemaless-node-config.mdx reference. Triage 5811370954 set the direction: the same build-time refusal and prescription at all three doors.