From d0fdea17ba942da593efd49fc3e81b37e87d1d89 Mon Sep 17 00:00:00 2001
From: kageroumado <mail@kagerou.glass>
Date: Tue, 6 Oct 2026 23:25:40 +0200
Subject: [PATCH] Match the asset's version the way the tag is parsed

A v1.8 tag decodes tolerantly to 1.8.0, and the asset was compared against
"<repo>-1.8.0", so MyApp-1.8.dmg never matched. The release was skipped
without an error, and every installed app treated it as nonexistent.
Parse the version in the asset name with the same tolerant parser and
compare versions instead of strings.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
---
 AppUpdater.swift                            | 13 ++++--
 README.md                                   |  3 +-
 Tests/AppUpdaterTests/AppUpdaterTests.swift | 44 ++++++++++++++++++++-
 3 files changed, 54 insertions(+), 6 deletions(-)

diff --git a/AppUpdater.swift b/AppUpdater.swift
index d403136..1c9fbb9 100644
--- a/AppUpdater.swift
+++ b/AppUpdater.swift
@@ -755,13 +755,18 @@ struct Release: Decodable, Comparable {
         }
     }
 
+    /// The DMG named `<repo>-<version>.dmg` for this release. The version in
+    /// the name is parsed the way the tag is, so `MyApp-2.1.dmg` matches a
+    /// `v2.1` tag even though the tag prints as `2.1.0`.
     func viableAsset(forRepo repo: String) -> Asset? {
-        assets.first { asset in
-            let prefix = "\(repo.lowercased())-\(tagName)"
+        let prefix = "\(repo.lowercased())-"
+        return assets.first { asset in
             let name = (asset.name as NSString).deletingPathExtension
                 .lowercased()
-
-            return name == prefix && asset.contentType == .dmg
+            guard asset.contentType == .dmg, name.hasPrefix(prefix) else {
+                return false
+            }
+            return Version(tolerant: name.dropFirst(prefix.count)) == tagName
         }
     }
 
diff --git a/README.md b/README.md
index 874fd0e..b88284e 100644
--- a/README.md
+++ b/README.md
@@ -43,7 +43,8 @@ $ ditto "$SWIFT_BIN/AppUpdater_AppUpdater.bundle" \
 ## Release layout
 
 AppUpdater only accepts DMG assets. Name each asset
-`<repository>-<semantic-version>.dmg`, for example `MyApp-2.1.0.dmg`.
+`<repository>-<version>.dmg`, for example `MyApp-2.1.0.dmg`. The version is
+read the way the tag is, so a `v2.1` release may name its asset `MyApp-2.1.dmg`.
 
 The mounted DMG must contain one top-level app. Its filename must match the
 installed app, including case. A release for `MyApp.app` therefore contains:
diff --git a/Tests/AppUpdaterTests/AppUpdaterTests.swift b/Tests/AppUpdaterTests/AppUpdaterTests.swift
index 2b40a27..56bb186 100644
--- a/Tests/AppUpdaterTests/AppUpdaterTests.swift
+++ b/Tests/AppUpdaterTests/AppUpdaterTests.swift
@@ -356,6 +356,46 @@ final class AppUpdaterTests: XCTestCase {
         }
     }
 
+    @MainActor
+    func testCheckMatchesAssetNamedWithShortVersion() async throws {
+        let releases = try [
+            release("v2.1", prerelease: false, assetName: "AppUpdater-2.1.dmg"),
+        ]
+        let updater = AppUpdater(
+            owner: "mxcl",
+            repo: "AppUpdater",
+            currentVersion: { Version(2, 0, 0) },
+            fetchReleases: { releases },
+            prepareAsset: { asset in preparedUpdate(assetName: asset.name) }
+        )
+
+        let update = try await updater.check()
+
+        XCTAssertEqual(update?.version, "2.1.0")
+        XCTAssertEqual(update?.assetName, "AppUpdater-2.1.dmg")
+    }
+
+    @MainActor
+    func testCheckDoesNotMatchAssetForAnotherVersion() async throws {
+        let releases = try [
+            release("v2.1", prerelease: false, assetName: "AppUpdater-2.1.1.dmg"),
+        ]
+        let updater = AppUpdater(
+            owner: "mxcl",
+            repo: "AppUpdater",
+            currentVersion: { Version(2, 0, 0) },
+            fetchReleases: { releases },
+            prepareAsset: { _ in
+                XCTFail("update should not run")
+                return preparedUpdate()
+            }
+        )
+
+        let update = try await updater.check()
+
+        XCTAssertNil(update)
+    }
+
     @MainActor
     func testCheckDoesNotUpdateWithoutMatchingAsset() async throws {
         let releases = try [
@@ -1447,7 +1487,9 @@ final class AppUpdaterTests: XCTestCase {
         }
         """.data(using: .utf8)!
 
-        return try JSONDecoder().decode(Release.self, from: json)
+        let decoder = JSONDecoder()
+        decoder.userInfo[.decodingMethod] = DecodingMethod.tolerant
+        return try decoder.decode(Release.self, from: json)
     }
 
     private func temporaryDirectory() throws -> URL {