fix(automation): stop logging the degraded "child run is gone" warning on the healthy subflow up-bubble

.changeset/subflow-upbubble-degraded-warning.md

@@ -0,0 +1,42 @@
+---
+"@objectstack/service-automation": patch
+---
+
+fix(automation): the healthy subflow up-bubble no longer logs the degraded "child run is gone" warning
+
+Every successful subflow completion logged, at `warn`:
+
+```
+[automation] run 'R' is paused at subflow node 'N' but child run 'C' is gone — continuing without child output
+```
+
+Both halves of that sentence were false on this path. The child had not gone
+anywhere — it had *completed*, which is the normal outcome — and the parent was
+continuing **with** the child's output, not without it: the very signal the
+engine was holding when it wrote the line already carried it.
+
+The cause is that the branch keyed off a suspension lookup. A parent parked at a
+`subflow` node correlates to its child as `subflow:CHILDID`, and on resume the
+engine calls `loadSuspendedRun(CHILDID)`. That finds only **SUSPENDED** runs, so
+a child that finished has no suspension to find, and the miss fell through to an
+`else` written for the genuinely degraded case. The lookup answers "is the child
+still parked", which on the up-bubble is a question about nothing: the child is
+supposed to be finished there.
+
+The branch now asks the fact the message is actually about — whether the incoming
+resume signal already carries the child's output, which is what the engine's own
+`buildSubflowResumeSignal` mints when a completed child bubbles into its parent.
+When it does, the run continues from the subflow node with a `debug` line naming
+the carried output. When there is no child run **and** no carried output, the
+degraded case is real and keeps its existing sentence at its existing level.
+
+The engine-built marker is part of the test, not decoration: `output` is a
+caller-writable field and on this node a caller's signal is delegated down to the
+child, so matching on shape alone would let a caller's own bag silence a genuine
+degraded warning. Only the engine can mint that marker.
+
+No behaviour changes: both branches continue the parent exactly as before, no log
+call site changes level, and the degraded sentence is untouched. This is a
+logging correctness fix — an ordinary outcome had been reported as a fault on
+every healthy subflow completion, which is the cry-wolf shape that trains an
+operator to skip the line on the one occasion it means what it says.

packages/services/service-automation/src/builtin/screen-resume-signal-less.test.ts

@@ -30,6 +30,28 @@ import { installBuiltinNodes } from './index.js';
 function silentLogger() {
     return { info() {}, warn() {}, error() {}, debug() {}, child() { return silentLogger(); } } as any;
 }
+
+/**
+ * A logger that RECORDS what it was told, level included — the engine's own
+ * sink for the tests that pin a log branch. `silentLogger` discards, so a
+ * branch can only be pinned on absence against something that keeps the calls
+ * (#14392).
+ */
+function recordingLogger(sink: Array<{ level: string; message: string }>) {
+    const rec = (level: string) => (message: unknown) => { sink.push({ level, message: String(message) }); };
+    const self: any = {
+        info: rec('info'), warn: rec('warn'), error: rec('error'), debug: rec('debug'),
+        child() { return self; },
+    };
+    return self;
+}
+
+/**
+ * The degraded up-bubble sentence, verbatim (#14392). Asserted by CONTENT and
+ * not by "some warn fired": the card is that this exact sentence described the
+ * healthy path.
+ */
+const DEGRADED_SENTENCE = 'is gone — continuing without child output';
 function ctx() {
     return { logger: silentLogger(), getService() { return undefined; } } as any;
 }
@@ -165,9 +187,12 @@ describe('signal-less resume of a pause that declares no contract proceeds (#136
 describe("engine-built continuation stays exempt — the flag is the ONLY exemption (#13648 negative control)", () => {
     let engine: AutomationEngine;
     let captured: unknown[];
+    /** #14392 — the engine's log records, so the up-bubble branch is pinnable. */
+    let records: Array<{ level: string; message: string }>;
 
     beforeEach(() => {
-        engine = new AutomationEngine(silentLogger());
+        records = [];
+        engine = new AutomationEngine(recordingLogger(records));
         installBuiltinNodes(engine, ctx());
         captured = [];
         // Copies the screen-collected `kind` into the child's declared output.
@@ -241,6 +266,54 @@ describe("engine-built continuation stays exempt — the flag is the ONLY exempt
         expect(childRes.status).toBeUndefined();
         expect(captured).toEqual([{ result: 'escalate' }]);
         expect(engine.listSuspendedRuns()).toHaveLength(0);
+
+        // [#14392] Pinned on the BRANCH, not on the sentence. This IS the
+        // engine-built up-bubble: `captured` one line up is the child's output
+        // arriving in the parent, so the parent continued *with* it. The
+        // degraded line claims the opposite and must be absent — it used to
+        // fire here on every healthy subflow completion, because the parent's
+        // `subflow:` correlation is looked up with `loadSuspendedRun` and a
+        // COMPLETED child has no suspension to find.
+        expect(records.filter((r) => r.message.includes(DEGRADED_SENTENCE))).toEqual([]);
+        // Not silent by accident either: the healthy continuation says what it
+        // is, once, at `debug` — never `warn`.
+        const bubbled = records.filter((r) => r.message.includes('engine-built up-bubble signal'));
+        expect(bubbled).toHaveLength(1);
+        expect(bubbled[0].level).toBe('debug');
+        expect(bubbled[0].message).toContain(child.runId);
+    });
+
+    it('[#14392 positive control] the degraded line still fires when the child run is gone AND nothing carries its output', async () => {
+        const started = await engine.execute('parent', {} as any);
+        const parentRunId = started.runId!;
+        const child = engine.listSuspendedRuns().find((r) => r.flowName === 'child')!;
+
+        // Make the child GENUINELY gone without bubbling anything up:
+        // `cancelRun` consumes the child's continuation only, leaving this
+        // parent parked on a `subflow:` correlation that now dangles.
+        expect(await engine.cancelRun(child.runId, 'abandoned')).toBe(true);
+        records.length = 0;
+
+        // A CALLER's signal this time — not the engine's — so nothing carries
+        // the child's output. `kind` satisfies the child's screen, which the
+        // parent surfaces as its own.
+        const res = await engine.resume(parentRunId, { variables: { kind: 'escalate' } });
+
+        const degraded = records.filter((r) => r.message.includes(DEGRADED_SENTENCE));
+        expect(degraded).toHaveLength(1);
+        // The level does NOT move (#13398-class): this branch keeps `warn`.
+        expect(degraded[0].level).toBe('warn');
+        expect(degraded[0].message).toContain(child.runId);
+        expect(degraded[0].message).toContain(parentRunId);
+        // ...and no debug up-bubble line, since there was no up-bubble.
+        expect(records.filter((r) => r.message.includes('engine-built up-bubble signal'))).toEqual([]);
+
+        // Behaviour unchanged: the branch still CONTINUES the parent, which is
+        // the whole point of the `else` — downstream ran, with no subflow
+        // output to map into `subResult`.
+        expect(res.success).toBe(true);
+        expect(captured).toEqual([undefined]);
+        expect(await engine.hasSuspendedRun(parentRunId)).toBe(false);
     });
 
     it("a signal-less resume of the CHILD is still refused — the flag exempts the engine's signal, not the run", async () => {

packages/services/service-automation/src/engine.ts

@@ -1037,6 +1037,31 @@ function engineBuilt(signal: ResumeSignal): ResumeSignal {
     return Object.assign(signal, { [ENGINE_BUILT_SIGNAL]: true });
 }
 
+/**
+ * Whether an incoming resume signal ALREADY carries a completed subflow
+ * child's output — the engine-built up-bubble, i.e. the signal
+ * `bubbleToParent` builds with `buildSubflowResumeSignal` when a delegated
+ * child finishes and continues its parent.
+ *
+ * The discriminator for the up-bubble's log branch, and deliberately NOT "is
+ * the child run still there". On the up-bubble the child has COMPLETED, so its
+ * suspension is already consumed and the `loadSuspendedRun` miss on the
+ * parent's `subflow:` correlation says nothing about whether the parent
+ * continues with the child's output — it only says the child is not SUSPENDED.
+ * Branching on a second run lookup would move that same confusion one call
+ * over; this asks the fact the message is actually about.
+ *
+ * The engine-built marker is load-bearing, not decoration: `output` is a
+ * caller-writable field, and on this node the caller's signal is delegated
+ * DOWN to the child, so shape alone would let a caller's own bag silence the
+ * genuine degraded warning. Only the engine can mint the symbol.
+ */
+function carriesSubflowChildOutput(signal: ResumeSignal): boolean {
+    if ((signal as Record<symbol, unknown>)[ENGINE_BUILT_SIGNAL] !== true) return false;
+    const output = signal.output;
+    return typeof output === 'object' && output !== null && 'output' in output;
+}
+
 /**
  * Variable names the flow engine owns: `$runId`, `$flowName`, `$flowLabel`,
  * `$record`, `$error`, `$parentRunId`, `$parentMapNode`, `$parentOutputVariable`,
@@ -5155,7 +5180,36 @@ export class AutomationEngine implements IAutomationService {
                     // #4354 — down-delegation is the other way a child's work
                     // lands under a parent step written at suspend time.
                     this.creditChildRun(run.steps, run.nodeId, childRes.summary);
+                } else if (carriesSubflowChildOutput(signal)) {
+                    // The engine-built UP-BUBBLE — the HEALTHY path, and the
+                    // one this `else` used to describe as a degradation. The
+                    // child COMPLETED and `bubbleToParent` resumed this run
+                    // with the child's mapped output, so the miss above is the
+                    // SUSPENSION lookup missing (a completed run has no
+                    // suspension), not the child having disappeared, and the
+                    // parent continues *with* the child's output — which is
+                    // what the old sentence denied outright.
+                    //
+                    // `debug`, for the same reason as the lost-advance-claim
+                    // record further down: an ordinary outcome logged at `warn`
+                    // on every healthy subflow completion is the cry-wolf
+                    // shape — the operator who reads "child run is gone" on
+                    // each one stops reading the line, and the one time it
+                    // means what it says is the time it is ignored. Nothing
+                    // else moves: this branch continues the parent exactly as
+                    // before, and the degraded branch below keeps its text and
+                    // its level.
+                    this.logger.debug(
+                        `[automation] run '${runId}' continues from subflow node '${run.nodeId}' with the output of ` +
+                            `completed child run '${childRunId}' — carried on the engine-built up-bubble signal ` +
+                            `(the child's suspension is consumed, which is why it is not loadable here).`,
+                    );
                 } else {
+                    // The genuinely degraded case, and the only one the
+                    // sentence below was ever true of: nothing suspended under
+                    // the child id AND no carried output, so this run really
+                    // does continue without the child's output. #4632 verdict:
+                    // FUNCTIONAL — stays `warn`.
                     this.logger.warn(
                         `[automation] run '${runId}' is paused at subflow node '${run.nodeId}' but child run '${childRunId}' ` +
                             `is gone — continuing without child output`,