From 5e6b06f009ce34d759864911af948428d654989d Mon Sep 17 00:00:00 2001
From: bbassie <17990055+bbassie@users.noreply.github.com>
Date: Tue, 18 Aug 2026 14:30:32 +0000
Subject: [PATCH] Filter dependency resolution by the mod pack's Factorio
 version

The dependency resolver picked the newest release satisfying the version
range regardless of which Factorio version it targeted, so a 2.0 mod pack
could end up with 2.1 dependencies. Only consider portal releases and
local mods whose factorio_version matches the mod pack.

Fixes #965

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 packages/controller/src/ControlConnection.ts | 15 +++-
 test/controller/ControlConnection.test.js    | 73 ++++++++++++++++++++
 2 files changed, 85 insertions(+), 3 deletions(-)

diff --git a/packages/controller/src/ControlConnection.ts b/packages/controller/src/ControlConnection.ts
index 6baf2fe4..c9c9f8b0 100644
--- a/packages/controller/src/ControlConnection.ts
+++ b/packages/controller/src/ControlConnection.ts
@@ -713,9 +713,14 @@ export default class ControlConnection extends BaseConnection {
 				return null;
 			}
 
-			// Select the latest matching version
+			// Select the latest matching version for the mod pack's Factorio version
 			const release = releases.releases
-				.filter(info => versionRange.testVersion(info.version))
+				.filter(info => (
+					versionRange.testVersion(info.version)
+					&& lib.normaliseMajorMinorVersion(
+						lib.normaliseSourceVersion(info.info_json.factorio_version)
+					) === factorioVersion
+				))
 				.reduce<ModPortalReleaseType | undefined>((max, cur) => (
 					max && lib.integerSourceVersion(max.version) > lib.integerSourceVersion(cur.version) ? max : cur
 				), undefined);
@@ -797,7 +802,11 @@ export default class ControlConnection extends BaseConnection {
 
 			// Check if a local version fits the requirements
 			let candidate = localInfos
-				.filter(info => (info.name === mod.name && versionRange.testVersion(info.version)))
+				.filter(info => (
+					info.name === mod.name
+					&& info.factorioVersion === factorioVersion
+					&& versionRange.testVersion(info.version)
+				))
 				.reduce<lib.ModInfo | undefined>((max, cur) => (
 					max && max.integerVersion > cur.integerVersion ? max : cur
 				), undefined);
diff --git a/test/controller/ControlConnection.test.js b/test/controller/ControlConnection.test.js
index 90483a08..f0cbccb7 100644
--- a/test/controller/ControlConnection.test.js
+++ b/test/controller/ControlConnection.test.js
@@ -1,5 +1,6 @@
 "use strict";
 const assert = require("assert").strict;
+const lib = require("@clusterio/lib");
 const { ControlConnection } = require("@clusterio/controller");
 
 describe("controller/src/ControlConnection", function() {
@@ -39,4 +40,76 @@ describe("controller/src/ControlConnection", function() {
 			assert.equal(mockController.stopped, false);
 		});
 	});
+
+	describe(".handleModDependencyResolveRequest()", function() {
+		const originalFetchModReleases = lib.ModStore.fetchModReleases;
+		const portal = new Map();
+		let localMods;
+
+		function release(version, factorioVersion, dependencies = []) {
+			return {
+				version, sha1: "0".repeat(40),
+				info_json: { factorio_version: factorioVersion, dependencies },
+			};
+		}
+
+		before(function() {
+			lib.ModStore.fetchModReleases = async (name) => {
+				const releases = portal.get(name);
+				if (!releases) {
+					throw new Error("Fetch: returned 404 Not Found");
+				}
+				return { name, owner: "owner", title: name, releases };
+			};
+		});
+		after(function() {
+			lib.ModStore.fetchModReleases = originalFetchModReleases;
+		});
+		beforeEach(function() {
+			portal.clear();
+			localMods = [];
+		});
+
+		async function resolve(mods, factorioVersion, checkForUpdates = false) {
+			const response = await ControlConnection.prototype.handleModDependencyResolveRequest.call(
+				{ _controller: { modStore: { mods: () => localMods } } },
+				new lib.ModDependencyResolveRequest(
+					mods.map(mod => new lib.ModDependency(mod)), factorioVersion, checkForUpdates,
+				),
+			);
+			return new Map(response.dependencies.map(mod => [mod.name, mod]));
+		}
+
+		it("only selects portal releases matching the mod pack's Factorio version", async function() {
+			portal.set("root", [release("1.0.0", "2.0", ["dep"]), release("1.1.0", "2.1", ["dep"])]);
+			portal.set("dep", [
+				release("1.0.0", "1.1"),
+				release("2.0.0", "2.0"),
+				release("3.0.0", "2.1"),
+			]);
+			assert.equal((await resolve(["root = 1.0.0"], "2.0")).get("dep").version, "2.0.0");
+			assert.equal((await resolve(["root = 1.1.0"], "2.1")).get("dep").version, "3.0.0");
+		});
+
+		it("only selects local mods matching the mod pack's Factorio version", async function() {
+			portal.set("root", [release("1.0.0", "2.0", ["dep"])]);
+			portal.set("dep", [release("2.0.0", "2.0")]);
+			localMods = [
+				lib.ModInfo.fromJSON({ name: "dep", version: "3.0.0", factorio_version: "2.1" }),
+				lib.ModInfo.fromJSON({ name: "dep", version: "1.0.0", factorio_version: "2.0" }),
+			];
+			assert.equal((await resolve(["root = 1.0.0"], "2.0")).get("dep").version, "1.0.0");
+			assert.equal((await resolve(["root = 1.0.0"], "2.0", true)).get("dep").version, "2.0.0");
+		});
+
+		it("reports dependencies without a matching Factorio version as not found", async function() {
+			portal.set("root", [release("1.0.0", "2.0", ["dep"])]);
+			portal.set("dep", [release("3.0.0", "2.1")]);
+			const response = await ControlConnection.prototype.handleModDependencyResolveRequest.call(
+				{ _controller: { modStore: { mods: () => localMods } } },
+				new lib.ModDependencyResolveRequest([new lib.ModDependency("root = 1.0.0")], "2.0", false),
+			);
+			assert.equal(response.errors.get("dep"), "notFound");
+		});
+	});
 });