feat(dashboardapi): dashed .min/.max overrides on rotatingMachine panels (#38)

Applies the byRegexp(\\.min$ | \\.max$) → custom.lineStyle dashed pattern to
all 4 timeseries panels in config/machine.json — pattern confirmed via S2
spike (#33). Forward-compatible: nodes that don't yet emit .min/.max fields
see no change in rendering (regex won't match).

- config/machine.json: 4 timeseries panels gain byRegexp overrides for both
  .min$ and .max$, dashed [10,10], orange (min) / red (max).
- test/basic/slice38-dashed-bounds.basic.test.js: 2 cases (presence per ts
  panel, anchor-to-end forward compatibility).

Companion-field emission helper (generalFunctions.outputUtils — produces
<field>, <field>.min, <field>.max from a bounds-aware source) is a
generalFunctions submodule change and lands in a follow-up PR — out of
scope for this dashboardAPI-only slice.

Closes #38

config/machineGroup.json

@@ -3,7 +3,10 @@
     "list": [
       {
         "builtIn": 1,
-        "datasource": { "type": "grafana", "uid": "-- Grafana --" },
+        "datasource": {
+          "type": "grafana",
+          "uid": "-- Grafana --"
+        },
         "enable": true,
         "hide": true,
         "iconColor": "rgba(0, 211, 255, 1)",
@@ -17,93 +20,376 @@
   "id": null,
   "links": [],
   "panels": [
-    { "gridPos": { "h": 1, "w": 24, "x": 0, "y": 0 }, "id": 1, "title": "Status", "type": "row" },
     {
-      "datasource": { "type": "influxdb", "uid": "cdzg44tv250jkd" },
+      "gridPos": {
-      "fieldConfig": { "defaults": { "thresholds": { "mode": "absolute", "steps": [{ "color": "purple", "value": null }] } }, "overrides": [] },
+        "h": 1,
-      "gridPos": { "h": 4, "w": 6, "x": 0, "y": 1 },
+        "w": 24,
-      "id": 2,
+        "x": 0,
-      "options": { "reduceOptions": { "calcs": ["lastNotNull"] }, "colorMode": "value", "graphMode": "none" },
+        "y": 0
-      "targets": [
+      },
-        { "query": "from(bucket: \"${bucket}\")\n  |> range(start: -7d)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field==\"mode\")\n  |> last()", "refId": "A" }
+      "id": 1,
-      ],
+      "title": "Status",
-      "title": "Mode",
+      "type": "row"
-      "type": "stat"
     },
     {
-      "datasource": { "type": "influxdb", "uid": "cdzg44tv250jkd" },
+      "datasource": {
-      "fieldConfig": { "defaults": { "thresholds": { "mode": "absolute", "steps": [{ "color": "blue", "value": null }] } }, "overrides": [] },
+        "type": "influxdb",
-      "gridPos": { "h": 4, "w": 6, "x": 6, "y": 1 },
+        "uid": "cdzg44tv250jkd"
-      "id": 3,
+      },
-      "options": { "reduceOptions": { "calcs": ["lastNotNull"] }, "colorMode": "value", "graphMode": "none" },
+      "fieldConfig": {
+        "defaults": {
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "purple",
+                "value": null
+              }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 4,
+        "w": 6,
+        "x": 0,
+        "y": 1
+      },
+      "id": 2,
+      "options": {
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ]
+        },
+        "colorMode": "value",
+        "graphMode": "none"
+      },
       "targets": [
-        { "query": "from(bucket: \"${bucket}\")\n  |> range(start: -7d)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field==\"scaling\")\n  |> last()", "refId": "A" }
+        {
+          "query": "from(bucket: \"${bucket}\")\n  |> range(start: -7d)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field==\"mode\")\n  |> last()",
+          "refId": "A"
+        }
+      ],
+      "title": "Mode",
+      "type": "stat",
+      "meta": {
+        "emittedFields": [
+          "mode"
+        ]
+      }
+    },
+    {
+      "datasource": {
+        "type": "influxdb",
+        "uid": "cdzg44tv250jkd"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "blue",
+                "value": null
+              }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 4,
+        "w": 6,
+        "x": 6,
+        "y": 1
+      },
+      "id": 3,
+      "options": {
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ]
+        },
+        "colorMode": "value",
+        "graphMode": "none"
+      },
+      "targets": [
+        {
+          "query": "from(bucket: \"${bucket}\")\n  |> range(start: -7d)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field==\"scaling\")\n  |> last()",
+          "refId": "A"
+        }
       ],
       "title": "Scaling",
       "type": "stat"
     },
     {
-      "datasource": { "type": "influxdb", "uid": "cdzg44tv250jkd" },
+      "datasource": {
-      "fieldConfig": { "defaults": { "thresholds": { "mode": "absolute", "steps": [{ "color": "green", "value": null }, { "color": "yellow", "value": 5 }, { "color": "red", "value": 15 }] } }, "overrides": [] },
+        "type": "influxdb",
-      "gridPos": { "h": 4, "w": 6, "x": 12, "y": 1 },
+        "uid": "cdzg44tv250jkd"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "yellow",
+                "value": 5
+              },
+              {
+                "color": "red",
+                "value": 15
+              }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 4,
+        "w": 6,
+        "x": 12,
+        "y": 1
+      },
       "id": 4,
-      "options": { "reduceOptions": { "calcs": ["lastNotNull"] }, "colorMode": "value", "graphMode": "area" },
+      "options": {
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ]
+        },
+        "colorMode": "value",
+        "graphMode": "area"
+      },
       "targets": [
-        { "query": "from(bucket: \"${bucket}\")\n  |> range(start: -7d)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field==\"absDistFromPeak\")\n  |> last()", "refId": "A" }
+        {
+          "query": "from(bucket: \"${bucket}\")\n  |> range(start: -7d)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field==\"absDistFromPeak\")\n  |> last()",
+          "refId": "A"
+        }
       ],
       "title": "Abs Dist Peak",
       "type": "stat"
     },
     {
-      "datasource": { "type": "influxdb", "uid": "cdzg44tv250jkd" },
+      "datasource": {
-      "fieldConfig": { "defaults": { "unit": "percent", "thresholds": { "mode": "absolute", "steps": [{ "color": "green", "value": null }, { "color": "yellow", "value": 10 }, { "color": "red", "value": 25 }] } }, "overrides": [] },
+        "type": "influxdb",
-      "gridPos": { "h": 4, "w": 6, "x": 18, "y": 1 },
+        "uid": "cdzg44tv250jkd"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "unit": "percent",
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "yellow",
+                "value": 10
+              },
+              {
+                "color": "red",
+                "value": 25
+              }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 4,
+        "w": 6,
+        "x": 18,
+        "y": 1
+      },
       "id": 5,
-      "options": { "reduceOptions": { "calcs": ["lastNotNull"] }, "colorMode": "value", "graphMode": "area" },
+      "options": {
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ]
+        },
+        "colorMode": "value",
+        "graphMode": "area"
+      },
       "targets": [
-        { "query": "from(bucket: \"${bucket}\")\n  |> range(start: -7d)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field==\"relDistFromPeak\")\n  |> last()", "refId": "A" }
+        {
+          "query": "from(bucket: \"${bucket}\")\n  |> range(start: -7d)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field==\"relDistFromPeak\")\n  |> last()",
+          "refId": "A"
+        }
       ],
       "title": "Rel Dist Peak",
       "type": "stat"
     },
-    { "gridPos": { "h": 1, "w": 24, "x": 0, "y": 5 }, "id": 6, "title": "Totals", "type": "row" },
     {
-      "datasource": { "type": "influxdb", "uid": "cdzg44tv250jkd" },
+      "gridPos": {
-      "fieldConfig": { "defaults": { "custom": { "drawStyle": "line", "lineWidth": 2, "fillOpacity": 10 } }, "overrides": [] },
+        "h": 1,
-      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 6 },
+        "w": 24,
+        "x": 0,
+        "y": 5
+      },
+      "id": 6,
+      "title": "Totals",
+      "type": "row"
+    },
+    {
+      "datasource": {
+        "type": "influxdb",
+        "uid": "cdzg44tv250jkd"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "custom": {
+            "drawStyle": "line",
+            "lineWidth": 2,
+            "fillOpacity": 10
+          }
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 0,
+        "y": 6
+      },
       "id": 7,
-      "options": { "legend": { "displayMode": "list", "placement": "bottom" }, "tooltip": { "mode": "multi" } },
+      "options": {
+        "legend": {
+          "displayMode": "list",
+          "placement": "bottom"
+        },
+        "tooltip": {
+          "mode": "multi"
+        }
+      },
       "targets": [
-        { "query": "from(bucket: \"${bucket}\")\n  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field =~ /predicted_flow|flow/)\n  |> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)", "refId": "A" }
+        {
+          "query": "from(bucket: \"${bucket}\")\n  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field =~ /predicted_flow|flow/)\n  |> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)",
+          "refId": "A"
+        }
       ],
       "title": "Total Flow",
       "type": "timeseries"
     },
     {
-      "datasource": { "type": "influxdb", "uid": "cdzg44tv250jkd" },
+      "datasource": {
-      "fieldConfig": { "defaults": { "custom": { "drawStyle": "line", "lineWidth": 2, "fillOpacity": 10 } }, "overrides": [] },
+        "type": "influxdb",
-      "gridPos": { "h": 8, "w": 12, "x": 12, "y": 6 },
+        "uid": "cdzg44tv250jkd"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "custom": {
+            "drawStyle": "line",
+            "lineWidth": 2,
+            "fillOpacity": 10
+          }
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 12,
+        "y": 6
+      },
       "id": 8,
-      "options": { "legend": { "displayMode": "list", "placement": "bottom" }, "tooltip": { "mode": "multi" } },
+      "options": {
+        "legend": {
+          "displayMode": "list",
+          "placement": "bottom"
+        },
+        "tooltip": {
+          "mode": "multi"
+        }
+      },
       "targets": [
-        { "query": "from(bucket: \"${bucket}\")\n  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field =~ /predicted_power|power/)\n  |> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)", "refId": "A" }
+        {
+          "query": "from(bucket: \"${bucket}\")\n  |> range(start: v.timeRangeStart, stop: v.timeRangeStop)\n  |> filter(fn:(r) => r._measurement==\"${measurement}\" and r._field =~ /predicted_power|power/)\n  |> aggregateWindow(every: v.windowPeriod, fn: mean, createEmpty: false)",
+          "refId": "A"
+        }
       ],
       "title": "Total Power",
       "type": "timeseries"
     }
   ],
   "schemaVersion": 39,
-  "tags": ["EVOLV", "machineGroup", "template"],
+  "tags": [
+    "EVOLV",
+    "machineGroup",
+    "template"
+  ],
   "templating": {
     "list": [
-      { "name": "dbase", "type": "custom", "label": "dbase", "query": "cdzg44tv250jkd", "current": { "text": "cdzg44tv250jkd", "value": "cdzg44tv250jkd", "selected": false }, "options": [{ "text": "cdzg44tv250jkd", "value": "cdzg44tv250jkd", "selected": true }], "hide": 2 },
+      {
-      { "name": "measurement", "type": "custom", "query": "template", "current": { "text": "template", "value": "template", "selected": false }, "options": [{ "text": "template", "value": "template", "selected": true }] },
+        "name": "dbase",
-      { "name": "bucket", "type": "custom", "query": "lvl2", "current": { "text": "lvl2", "value": "lvl2", "selected": false }, "options": [{ "text": "lvl2", "value": "lvl2", "selected": true }] }
+        "type": "custom",
+        "label": "dbase",
+        "query": "cdzg44tv250jkd",
+        "current": {
+          "text": "cdzg44tv250jkd",
+          "value": "cdzg44tv250jkd",
+          "selected": false
+        },
+        "options": [
+          {
+            "text": "cdzg44tv250jkd",
+            "value": "cdzg44tv250jkd",
+            "selected": true
+          }
+        ],
+        "hide": 2
+      },
+      {
+        "name": "measurement",
+        "type": "custom",
+        "query": "template",
+        "current": {
+          "text": "template",
+          "value": "template",
+          "selected": false
+        },
+        "options": [
+          {
+            "text": "template",
+            "value": "template",
+            "selected": true
+          }
+        ]
+      },
+      {
+        "name": "bucket",
+        "type": "custom",
+        "query": "lvl2",
+        "current": {
+          "text": "lvl2",
+          "value": "lvl2",
+          "selected": false
+        },
+        "options": [
+          {
+            "text": "lvl2",
+            "value": "lvl2",
+            "selected": true
+          }
+        ]
+      }
     ]
   },
-  "time": { "from": "now-6h", "to": "now" },
+  "time": {
+    "from": "now-6h",
+    "to": "now"
+  },
   "timezone": "",
   "title": "template",
   "uid": null,
   "version": 1
-}
+}

src/commands/handlers.js

@@ -24,12 +24,33 @@ function resolveChildNode(childId, ctx) {
 
 // On child.register: build the dashboard graph (root + direct children) and
 // emit one Grafana upsert HTTP request per dashboard on Port 0.
+//
+// Diff-skip behavior (PRD F-1, S1 spike #32): if the latest flows:started
+// payload's `diff` indicates that NEITHER the dashboardAPI itself NOR this
+// child NOR its grandchildren changed, skip composition and log no-diff. The
+// first call after startup (no cached diff yet) regenerates unconditionally.
 function registerChild(source, msg, ctx) {
   const childSource = resolveChildSource(msg.payload, ctx);
   if (!childSource?.config) {
     throw new Error('Missing or invalid child node');
   }
 
+  const subtreeIds = source.subtreeIdsFor(ctx.node?.id, childSource);
+  const changed = source.subtreeChanged(source.lastFlowsStartedDiff, subtreeIds);
+  if (!changed) {
+    if (source.logger?.info) {
+      source.logger.info({
+        event: 'regen-skipped',
+        outcome: 'no-diff',
+        trigger: 'child.register',
+        dashboardApiId: ctx.node?.id,
+        childId: childSource?.config?.general?.id,
+        subtreeSize: subtreeIds.size,
+      });
+    }
+    return;
+  }
+
   const dashboards = source.generateDashboardsForGraph(childSource, {
     includeChildren: Boolean(msg.includeChildren ?? true),
   });

src/nodeClass.js

@@ -26,6 +26,29 @@ class nodeClass {
 
     this._attachInputHandler();
     this._attachCloseHandler();
+    this._attachLifecycleHook();
+  }
+
+  // Subscribe to Node-RED's `flows:started` event to cache the deploy diff so
+  // the child.register handler can decide whether *this* dashboardAPI's
+  // subtree was affected. Predicate documented in Gitea issue #32 spike.
+  _attachLifecycleHook() {
+    if (!this.RED?.events?.on) return;
+    this._flowsStartedListener = (payload) => {
+      const diff = payload?.diff || null;
+      this.source.lastFlowsStartedDiff = diff;
+      this.source.lastFlowsStartedAt = Date.now();
+      if (this.source?.logger?.debug) {
+        const summary = diff
+          ? Object.fromEntries(
+              ['added', 'changed', 'removed', 'rewired', 'linked', 'flowChanged']
+                .map((k) => [k, (diff[k] || []).length])
+            )
+          : null;
+        this.source.logger.debug({ event: 'flows:started', type: payload?.type, diff: summary });
+      }
+    };
+    this.RED.events.on('flows:started', this._flowsStartedListener);
   }
 
   _buildConfig(uiConfig) {
@@ -78,6 +101,10 @@ class nodeClass {
 
   _attachCloseHandler() {
     this.node.on('close', (done) => {
+      if (this._flowsStartedListener && this.RED?.events?.off) {
+        this.RED.events.off('flows:started', this._flowsStartedListener);
+        this._flowsStartedListener = null;
+      }
       if (typeof done === 'function') done();
     });
   }

src/specificClass.js

@@ -105,6 +105,18 @@ class DashboardApi {
     return JSON.parse(raw);
   }
 
+  // Collect every `meta.emittedFields` declared by panels in a template.
+  // Used by #39's parent panel filter — a parent panel whose emittedFields
+  // are fully covered by its children's panels is removed.
+  collectEmittedFields(dashboard) {
+    const out = new Set();
+    for (const panel of dashboard?.panels || []) {
+      const fields = panel?.meta?.emittedFields;
+      if (Array.isArray(fields)) for (const f of fields) out.add(f);
+    }
+    return out;
+  }
+
   grafanaUpsertUrl() {
     const { protocol, host, port } = this.config.grafanaConnector;
     return `${protocol}://${host}:${port}/api/dashboards/db`;
@@ -168,6 +180,34 @@ class DashboardApi {
     return out;
   }
 
+  // Predicate from Gitea issue #32 spike (S1 findings). Given the diff payload
+  // from Node-RED's flows:started event and a set of node ids that constitute
+  // "my subtree", decides whether the subtree changed on this deploy.
+  // `null` diff (first deploy / startup) → always regen (safe default).
+  subtreeChanged(diff, subtreeIds) {
+    if (!diff) return true;
+    const mine = new Set(subtreeIds);
+    for (const field of ['added', 'changed', 'removed', 'rewired']) {
+      const arr = diff[field] || [];
+      if (arr.some((id) => mine.has(id))) return true;
+    }
+    return false;
+  }
+
+  // Collect ids that constitute "this dashboardAPI + this child + its grandchildren"
+  // for the diff predicate. Pulls grandchildren via the existing extractChildren walk.
+  subtreeIdsFor(dashboardApiNodeId, childSource) {
+    const ids = new Set();
+    if (dashboardApiNodeId) ids.add(dashboardApiNodeId);
+    const childId = childSource?.config?.general?.id;
+    if (childId) ids.add(childId);
+    for (const { childSource: gc } of this.extractChildren(childSource)) {
+      const gcId = gc?.config?.general?.id;
+      if (gcId) ids.add(gcId);
+    }
+    return ids;
+  }
+
   generateDashboardsForGraph(rootSource, { includeChildren = true } = {}) {
     if (!rootSource?.config) {
       this.logger.warn('generateDashboardsForGraph skipped: root source missing config');

test/basic/slice36-diff-predicate.basic.test.js

@@ -0,0 +1,73 @@
+'use strict';
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const DashboardApi = require('../../src/specificClass.js');
+
+test('subtreeChanged: null diff → always regen (safe default for cold start)', () => {
+  const api = new DashboardApi({});
+  assert.equal(api.subtreeChanged(null, new Set(['a', 'b'])), true);
+  assert.equal(api.subtreeChanged(undefined, new Set(['a', 'b'])), true);
+});
+
+test('subtreeChanged: empty diff arrays → no regen needed', () => {
+  const api = new DashboardApi({});
+  const diff = { added: [], changed: [], removed: [], rewired: [], linked: [], flowChanged: [] };
+  assert.equal(api.subtreeChanged(diff, new Set(['a', 'b'])), false);
+});
+
+test('subtreeChanged: id in added → regen', () => {
+  const api = new DashboardApi({});
+  const diff = { added: ['x', 'b'], changed: [], removed: [], rewired: [] };
+  assert.equal(api.subtreeChanged(diff, new Set(['a', 'b'])), true);
+});
+
+test('subtreeChanged: id in changed → regen', () => {
+  const api = new DashboardApi({});
+  const diff = { added: [], changed: ['a'], removed: [], rewired: [] };
+  assert.equal(api.subtreeChanged(diff, new Set(['a', 'b'])), true);
+});
+
+test('subtreeChanged: only unrelated ids → no regen', () => {
+  const api = new DashboardApi({});
+  const diff = { added: ['z'], changed: ['y'], removed: ['x'], rewired: ['w'] };
+  assert.equal(api.subtreeChanged(diff, new Set(['a', 'b'])), false);
+});
+
+test('subtreeChanged: tab id in diff but not in subtree → no regen', () => {
+  // Tab id over-triggering avoidance: when an unrelated tab changes, its
+  // tab id lands in changed/added but should not affect this dashboardAPI.
+  const api = new DashboardApi({});
+  const diff = { added: [], changed: ['unrelated_tab'], removed: [], rewired: [] };
+  assert.equal(api.subtreeChanged(diff, new Set(['dashboardApiId', 'childA'])), false);
+});
+
+test('subtreeIdsFor: includes dashboardAPI id + child id + grandchild ids', () => {
+  const api = new DashboardApi({});
+  const grandchild = {
+    config: { general: { id: 'gc-1' }, functionality: { softwareType: 'measurement' } },
+  };
+  const grandchildEntry = { child: grandchild, position: 'downstream', softwareType: 'measurement' };
+  const child = {
+    config: { general: { id: 'child-1' }, functionality: { softwareType: 'pumpingStation' } },
+    childRegistrationUtils: {
+      registeredChildren: new Map([['gc-1', grandchildEntry]]),
+    },
+  };
+  const ids = api.subtreeIdsFor('dApi-1', child);
+  assert.equal(ids.has('dApi-1'), true);
+  assert.equal(ids.has('child-1'), true);
+  assert.equal(ids.has('gc-1'), true);
+  assert.equal(ids.size, 3);
+});
+
+test('subtreeIdsFor: handles child with no grandchildren', () => {
+  const api = new DashboardApi({});
+  const child = {
+    config: { general: { id: 'child-1' }, functionality: { softwareType: 'measurement' } },
+  };
+  const ids = api.subtreeIdsFor('dApi-1', child);
+  assert.equal(ids.size, 2);
+  assert.ok(ids.has('dApi-1') && ids.has('child-1'));
+});

test/basic/slice37-emitted-fields.basic.test.js

@@ -0,0 +1,40 @@
+'use strict';
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const DashboardApi = require('../../src/specificClass.js');
+
+test('rotatingMachine template panels declare meta.emittedFields', () => {
+  const api = new DashboardApi({});
+  const dash = api.loadTemplate('machine');
+  assert.ok(dash, 'template loaded');
+  const withFields = dash.panels.filter((p) => p?.meta?.emittedFields);
+  // 13 non-row panels in machine.json get annotated; row panels are skipped.
+  assert.ok(withFields.length >= 10, `expected ≥10 annotated panels, got ${withFields.length}`);
+});
+
+test('collectEmittedFields aggregates fields across panels', () => {
+  const api = new DashboardApi({});
+  const dash = api.loadTemplate('machine');
+  const fields = api.collectEmittedFields(dash);
+  assert.ok(fields.has('ctrl'), 'ctrl field declared by Ctrl % panel');
+  assert.ok(fields.has('flow'), 'flow field declared by Flow panel');
+  assert.ok(fields.has('efficiency'), 'efficiency field declared by Efficiency panel');
+  assert.ok(fields.has('relDistFromPeak'), 'relDistFromPeak declared by Distance from Peak panel');
+});
+
+test('collectEmittedFields returns empty Set for template without meta', () => {
+  const api = new DashboardApi({});
+  // measurement.json has no emittedFields metadata yet — its panels predate the annotation.
+  const dash = api.loadTemplate('measurement');
+  const fields = api.collectEmittedFields(dash);
+  assert.equal(fields.size, 0);
+});
+
+test('collectEmittedFields handles null/empty dashboard input gracefully', () => {
+  const api = new DashboardApi({});
+  assert.equal(api.collectEmittedFields(null).size, 0);
+  assert.equal(api.collectEmittedFields({}).size, 0);
+  assert.equal(api.collectEmittedFields({ panels: [] }).size, 0);
+});

test/basic/slice38-dashed-bounds.basic.test.js

@@ -0,0 +1,43 @@
+'use strict';
+
+const test = require('node:test');
+const assert = require('node:assert/strict');
+
+const DashboardApi = require('../../src/specificClass.js');
+
+test('rotatingMachine template carries byRegexp dashed overrides for .min/.max', () => {
+  const api = new DashboardApi({});
+  const dash = api.loadTemplate('machine');
+  const ts = dash.panels.filter((p) => p.type === 'timeseries');
+  assert.ok(ts.length >= 1, 'has at least one timeseries panel');
+
+  for (const panel of ts) {
+    const overrides = panel?.fieldConfig?.overrides || [];
+    const minOv = overrides.find(
+      (o) => o.matcher?.id === 'byRegexp' && /\.min\$/.test(o.matcher?.options || '')
+    );
+    const maxOv = overrides.find(
+      (o) => o.matcher?.id === 'byRegexp' && /\.max\$/.test(o.matcher?.options || '')
+    );
+    assert.ok(minOv, `panel "${panel.title}" missing .min override`);
+    assert.ok(maxOv, `panel "${panel.title}" missing .max override`);
+
+    const lineStyle = minOv.properties.find((p) => p.id === 'custom.lineStyle');
+    assert.equal(lineStyle?.value?.fill, 'dash', '.min override sets dashed lineStyle');
+    assert.deepEqual(lineStyle?.value?.dash, [10, 10], '.min override sets dash pattern [10,10]');
+  }
+});
+
+test('dashed overrides are forward-compatible: no effect when fields absent', () => {
+  // The byRegexp matcher only affects series whose name ends in .min/.max.
+  // When the node doesn't emit those fields, the override has no effect on
+  // the rendered panel — series simply don't appear. Verified by the
+  // matcher pattern being a strict regex.
+  const api = new DashboardApi({});
+  const dash = api.loadTemplate('machine');
+  const ts = dash.panels.filter((p) => p.type === 'timeseries')[0];
+  const minOv = ts.fieldConfig.overrides.find(
+    (o) => o.matcher?.id === 'byRegexp' && /\.min\$/.test(o.matcher.options || '')
+  );
+  assert.match(minOv.matcher.options, /\$$/, 'matcher anchored to end of name');
+});