diff --git a/graph/__snapshots__/top_decl_deps_test.ts.snap b/graph/__snapshots__/top_decl_deps_test.ts.snap
index 7d89633..9a65ec1 100644
--- a/graph/__snapshots__/top_decl_deps_test.ts.snap
+++ b/graph/__snapshots__/top_decl_deps_test.ts.snap
@@ -2,18 +2,18 @@ export const snapshot = {};
 
 snapshot[`getTopDeclDeps() converts graph into valid TopDeclDeps 1`] = `
 {
-  "AliasedImport (/d.tsx:8:14)": [
-    "a (/a.ts:1:14)",
+  "vscode://file/b.tsx:5:14?kind=VariableDeclaration&name=CompAAA": [
+    "vscode://file/a.ts:3:14?kind=VariableDeclaration&name=aaa",
+    "vscode://file/a.ts:1:14?kind=VariableDeclaration&name=a",
   ],
-  "CompAAA (/b.tsx:5:14)": [
-    "aaa (/a.ts:3:14)",
-    "a (/a.ts:1:14)",
+  "vscode://file/d.tsx:4:14?kind=VariableDeclaration&name=InnerImport": [
+    "vscode://file/b.tsx:4:14?kind=VariableDeclaration&name=Comp",
+    "vscode://file/a.ts:1:14?kind=VariableDeclaration&name=a",
+    "vscode://file/c.tsx:7:14?kind=VariableDeclaration&name=Page",
+    "vscode://file/b.tsx:8:14?kind=VariableDeclaration&name=Unrelated",
   ],
-  "InnerImport (/d.tsx:4:14)": [
-    "Comp (/b.tsx:4:14)",
-    "a (/a.ts:1:14)",
-    "Page (/c.tsx:7:14)",
-    "Unrelated (/b.tsx:8:14)",
+  "vscode://file/d.tsx:8:14?kind=VariableDeclaration&name=AliasedImport": [
+    "vscode://file/a.ts:1:14?kind=VariableDeclaration&name=a",
   ],
 }
 `;
diff --git a/graph/_format.ts b/graph/_format.ts
index afa3f21..52b653f 100644
--- a/graph/_format.ts
+++ b/graph/_format.ts
@@ -2,7 +2,6 @@ import { Reducer, Stream } from "https://deno.land/x/rimbu@1.2.0/stream/mod.ts"
 import { encodeVSCodeURI, prettyPrintURI } from "./vscode_uri.ts"
 
 import type { Declaration, DeclDeps } from "./decl_deps.ts"
-import type { TopDeclDeps } from "./top_decl_deps.ts"
 
 export const serializeNoColor = (x: unknown) =>
 	Deno.inspect(x, {
@@ -28,14 +27,3 @@ export const declDepsSerializer = (declDeps: DeclDeps) =>
 	serializeNoColor(
 		asRecord((x) => prettyPrintURI(encodeVSCodeURI(x)))(declDeps),
 	)
-
-export const topDeclDepsSerializer = (topDeclDeps: TopDeclDeps): string =>
-	serializeNoColor(Object.fromEntries(
-		Array.from(topDeclDeps.entries())
-			.map(([decl, deps]) =>
-				[
-					prettyPrintURI(decl),
-					Array.from(deps).map(prettyPrintURI),
-				] as const
-			),
-	))
diff --git a/graph/graph_descendants.ts b/graph/graph_descendants.ts
index 69bb9c5..5303c13 100644
--- a/graph/graph_descendants.ts
+++ b/graph/graph_descendants.ts
@@ -44,7 +44,10 @@ export const graphDescendantsRaw = <T>(
  * TOP2 <- B, a, c
  * ```
  */
-export const graphDescendants = <T>(graph: ArrowGraph<T>): Map<T, Set<T>> =>
+// deno-lint-ignore no-explicit-any
+export const graphDescendants = <T extends keyof any>(
+	graph: ArrowGraph<T>,
+): Record<T, T[]> =>
 	graphDescendantsRaw(graph).stream()
-		.map(([k, v]) => [k, v.stream().reduce(Reducer.toJSSet())] as const)
-		.reduce(Reducer.toJSMap())
+		.map(([k, v]) => [k, [...v.stream().reduce(Reducer.toJSSet())]] as [T, T[]])
+		.reduce(Reducer.toJSObject())
diff --git a/graph/graph_descendants_test.ts b/graph/graph_descendants_test.ts
index d4271e9..57ae87d 100644
--- a/graph/graph_descendants_test.ts
+++ b/graph/graph_descendants_test.ts
@@ -15,10 +15,10 @@ Deno.test("graphDescendants() gets all valid path of directed graph", () => {
 
 	const result = graphDescendants(graph)
 
-	const expected = new Map([
-		["TOP1", new Set(["A", "a", "b"])],
-		["TOP2", new Set(["B", "a", "c"])],
-	])
+	const expected = {
+		TOP1: ["b", "A", "a"],
+		TOP2: ["a", "B", "c"],
+	}
 
 	assertEquals(result, expected)
 })
diff --git a/graph/top_decl_deps.ts b/graph/top_decl_deps.ts
index 1852b0f..1080aa1 100644
--- a/graph/top_decl_deps.ts
+++ b/graph/top_decl_deps.ts
@@ -3,7 +3,7 @@ import type { Graph } from "./graph.ts"
 import { VSCodeURI } from "./vscode_uri.ts"
 import { graphDescendants } from "./graph_descendants.ts"
 
-export type TopDeclDeps = Map<VSCodeURI, Set<VSCodeURI>>
+export type TopDeclDeps = Record<VSCodeURI, VSCodeURI[]>
 
 /**
  * Flattens graph of references into top-level links.
diff --git a/graph/top_decl_deps_test.ts b/graph/top_decl_deps_test.ts
index 96ff872..a05404f 100644
--- a/graph/top_decl_deps_test.ts
+++ b/graph/top_decl_deps_test.ts
@@ -7,7 +7,6 @@ import { getAllDecls } from "./decls.ts"
 import { declDepsToGraph } from "./graph.ts"
 import { getTopDeclDeps } from "./top_decl_deps.ts"
 import { snapshotTest } from "./_snapshot.ts"
-import { topDeclDepsSerializer } from "./_format.ts"
 
 snapshotTest(
 	"getTopDeclDeps() converts graph into valid TopDeclDeps",
@@ -20,6 +19,6 @@ snapshotTest(
 
 		const topDeclDeps = getTopDeclDeps(graph)
 
-		await assertSnapshot(t, topDeclDeps, { serializer: topDeclDepsSerializer })
+		await assertSnapshot(t, topDeclDeps)
 	},
 )