From c339d741843c65d3de1792f67ddf41540b46706e Mon Sep 17 00:00:00 2001
From: Felipe Lalanne <1822826+pipex@users.noreply.github.com>
Date: Wed, 3 Jan 2024 16:01:14 -0300
Subject: [PATCH] Do not recurse into arrays when constructing Target

The `Distance` module does not compare array elements, so the `Target`
constructor should not replace removed elements with `UNDEFINED`

Change-type: patch
---
 lib/distance.ts                     |  5 ++---
 lib/target.spec.ts                  | 11 +++++++++++
 lib/target.ts                       |  4 ++++
 tests/orchestrator/planning.spec.ts |  2 +-
 4 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/lib/distance.ts b/lib/distance.ts
index 697ac64..ed241e1 100644
--- a/lib/distance.ts
+++ b/lib/distance.ts
@@ -138,9 +138,8 @@ function* getOperations<S>(
  * Calculates the list of changes between the current state and the target
  */
 export function diff<S>(s: S, t: Target<S>): Array<Operation<S, any>> {
-	return [...getOperations(s, t)]
-		.filter(({ isLeaf }) => isLeaf)
-		.map(({ isLeaf, ...op }) => op);
+	const ops = [...getOperations(s, t)];
+	return ops.filter(({ isLeaf }) => isLeaf).map(({ isLeaf, ...op }) => op);
 }
 
 function from<S>(src: S, tgt: Target<S>): Distance<S> {
diff --git a/lib/target.spec.ts b/lib/target.spec.ts
index 3b6cf50..88ac5d5 100644
--- a/lib/target.spec.ts
+++ b/lib/target.spec.ts
@@ -66,5 +66,16 @@ describe('Target', () => {
 				g: { h: 'hello' },
 			});
 		});
+
+		it('does not iterate into arrays', () => {
+			type S = {
+				a?: string[];
+			};
+
+			const state: S = { a: ['foo', 'bar'] };
+			expect(Target.from(state, {})).to.deep.equal({ a: UNDEFINED });
+			expect(Target.from(state, { a: ['foo'] })).to.deep.equal({ a: ['foo'] });
+			expect(Target.from(state, { a: ['bar'] })).to.deep.equal({ a: ['bar'] });
+		});
 	});
 });
diff --git a/lib/target.ts b/lib/target.ts
index 5ab85e1..28a0d52 100644
--- a/lib/target.ts
+++ b/lib/target.ts
@@ -55,6 +55,10 @@ function from<S>(
 	while (queue.length > 0) {
 		const { s, t, p } = queue.shift()!;
 
+		// Don't recurse into arrays
+		if (Array.isArray(s) || Array.isArray(t)) {
+			continue;
+		}
 		for (const key of Object.keys(s)) {
 			if (key in t && t[key] === undefined && s[key] !== undefined) {
 				t[key] = UNDEFINED;
diff --git a/tests/orchestrator/planning.spec.ts b/tests/orchestrator/planning.spec.ts
index 744265f..e3c99ac 100644
--- a/tests/orchestrator/planning.spec.ts
+++ b/tests/orchestrator/planning.spec.ts
@@ -120,7 +120,7 @@ describe('orchestrator/planning', () => {
 				},
 			},
 			keys: {},
-			images: [{ name: 'a0_main:r0' }],
+			images: { 'a0_main:r0': { name: 'alpine:latest' } },
 		};
 
 		const result = planner.findPlan(device, {