feat: toggle to hide reads that don't trigger runs in the pipeline graph

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

frontend/src/lib/components/assets/AssetGraph/AssetGraphCanvas.svelte

@@ -25,6 +25,7 @@
 		assetsOnlyView,
 		upstreamDeletion,
 		NO_ASSET_NODE_ID,
+		withoutPassiveReads,
 		type AssetUpstream,
 		type AssetUpstreamDelete
 	} from './assetsOnlyView'
@@ -1359,7 +1360,21 @@
 		}
 		return { ...m, nodes, edges }
 	}
-	let view = $derived(assetsOnly ? assetsOnlyModel(model) : model)
+	// Reads that start nothing (lookups, reference tables) are often most of a
+	// graph's edges; hiding them leaves what makes the pipeline run. Remembered
+	// across pipelines.
+	const SHOW_PASSIVE_READS_KEY = 'pipeline-show-passive-reads'
+	let showPassiveReads = $state(true)
+	try {
+		showPassiveReads = localStorage.getItem(SHOW_PASSIVE_READS_KEY) !== 'false'
+	} catch {}
+	let withoutPassive = $derived(withoutPassiveReads(model.nodes, model.edges))
+	let shownModel = $derived(
+		showPassiveReads || withoutPassive.dropped === 0
+			? model
+			: { ...model, nodes: withoutPassive.nodes, edges: withoutPassive.edges }
+	)
+	let view = $derived(assetsOnly ? assetsOnlyModel(shownModel) : shownModel)
 
 	// dbt association, surfaced by emphasis instead of edges. Hovering a model's
 	// dbt badge lights up the project node that materializes it; hovering the
@@ -1901,7 +1916,7 @@
 		<PanToNode targetId={panToNodeId} {nodes} />
 		<Controls position="top-right" orientation="horizontal" showLock={false} class="!mr-10" />
 		{#if assetsOnlyToggle}
-			<Panel position="top-left" class="!m-3">
+			<Panel position="top-left" class="!m-3 flex flex-col gap-1.5">
 				<Toggle
 					checked={!assetsOnly}
 					size="xs"
@@ -1911,6 +1926,19 @@
 						if (assetsOnlyFolder != undefined) setAssetsOnlyFolder(assetsOnlyFolder, assetsOnly)
 					}}
 				/>
+				{#if withoutPassive.dropped > 0}
+					<Toggle
+						checked={showPassiveReads}
+						size="xs"
+						options={{ right: "Show reads that don't trigger runs" }}
+						on:change={(e) => {
+							showPassiveReads = e.detail
+							try {
+								localStorage.setItem(SHOW_PASSIVE_READS_KEY, String(e.detail))
+							} catch {}
+						}}
+					/>
+				{/if}
 			</Panel>
 		{/if}
 		{#if showMinimap}

frontend/src/lib/components/assets/AssetGraph/assetsOnlyView.test.ts

@@ -3,6 +3,7 @@ import {
 	assetsOnlyView,
 	upstreamDeletion,
 	NO_ASSET_NODE_ID,
+	withoutPassiveReads,
 	type AssetUpstream
 } from './assetsOnlyView'
 
@@ -134,3 +135,28 @@ describe('upstreamDeletion', () => {
 		expect(upstreamDeletion(u, script, all)).toBeUndefined()
 	})
 })
+
+describe('withoutPassiveReads', () => {
+	it('drops reads that trigger nothing, and the assets only they drew', () => {
+		const nodes = [
+			node('asset:src', 'asset'),
+			node('asset:lookup', 'asset'),
+			node('asset:out', 'asset'),
+			node('script:a', 'runnable')
+		]
+		const edges = [
+			edge('asset:src', 'script:a', 'lineage-read'),
+			edge('asset:src', 'script:a', 'trigger-asset'),
+			edge('asset:lookup', 'script:a', 'lineage-read'),
+			edge('asset:out', 'script:a', 'lineage-read'),
+			edge('script:a', 'asset:out', 'lineage-write')
+		]
+		const r = withoutPassiveReads(nodes, edges)
+		expect(r.nodes.map((n) => n.id)).toEqual(['asset:src', 'asset:out', 'script:a'])
+		expect(r.edges.map((e) => e.id)).toEqual([
+			'lineage-read:asset:src->script:a',
+			'trigger-asset:asset:src->script:a',
+			'lineage-write:script:a->asset:out'
+		])
+	})
+})

frontend/src/lib/components/assets/AssetGraph/assetsOnlyView.ts

@@ -186,3 +186,32 @@ export function upstreamDeletion(
 		trigger: ownTrigger ? { kind, path: t.data.ref, draft: !!t.data.draft } : undefined
 	}
 }
+
+/**
+ * The graph without its reads that start nothing: a read edge with no asset
+ * trigger along it, and the assets only such reads drew.
+ */
+export function withoutPassiveReads<N extends ViewNode, E extends ViewEdge>(
+	nodes: N[],
+	edges: E[]
+): { nodes: N[]; edges: E[]; dropped: number } {
+	const triggers = new Set(
+		edges.filter((e) => e.kind === 'trigger-asset').map((e) => `${e.source}\n${e.target}`)
+	)
+	const passive = (e: E) =>
+		e.kind === 'lineage-read' && !triggers.has(`${e.source}\n${e.target}`)
+	const kept = edges.filter((e) => !passive(e))
+	const dropped = edges.length - kept.length
+	if (dropped === 0) return { nodes, edges, dropped }
+	const linked = new Set(
+		kept.filter((e) => e.kind !== 'add-anchor').flatMap((e) => [e.source, e.target])
+	)
+	const readOnly = new Set(
+		edges.filter(passive).map((e) => e.source).filter((id) => !linked.has(id))
+	)
+	return {
+		nodes: nodes.filter((n) => !readOnly.has(n.id)),
+		edges: kept.filter((e) => !readOnly.has(e.source) && !readOnly.has(e.target)),
+		dropped
+	}
+}