From a9e38e3a1ca30ad7a195a0351487ea7225293834 Mon Sep 17 00:00:00 2001
From: Eugene Yokota <eed3si9n@gmail.com>
Date: Wed, 24 Dec 2025 20:26:52 -0500
Subject: [PATCH] [2.x] fix: Resolver.combineDefaultResolvers

**Problem**
combineDefaultResolvers loses information.

**Solution**
This fixes it.
---
 build.sbt                                     |  2 +
 .../sbt/librarymanagement/ResolverExtra.scala |  1 +
 .../librarymanagement/ResolverExtraTest.scala | 95 +++++++++++--------
 3 files changed, 60 insertions(+), 38 deletions(-)

diff --git a/build.sbt b/build.sbt
index 3205b07d5..193de309e 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1115,6 +1115,7 @@ lazy val lmCore = (project in file("lm-core"))
       scalatest % Test,
       scalacheck % Test,
       scalaVerify % Test,
+      hedgehog % Test,
     ),
     Compile / resourceGenerators += Def
       .task(
@@ -1157,6 +1158,7 @@ lazy val lmIvy = (project in file("lm-ivy"))
       scalatest % Test,
       scalacheck % Test,
       scalaVerify % Test,
+      hedgehog % Test,
     ),
     contrabandSettings,
     Test / classLoaderLayeringStrategy := ClassLoaderLayeringStrategy.Flat,
diff --git a/lm-core/src/main/scala/sbt/librarymanagement/ResolverExtra.scala b/lm-core/src/main/scala/sbt/librarymanagement/ResolverExtra.scala
index 3e0810782..635028b63 100644
--- a/lm-core/src/main/scala/sbt/librarymanagement/ResolverExtra.scala
+++ b/lm-core/src/main/scala/sbt/librarymanagement/ResolverExtra.scala
@@ -203,6 +203,7 @@ private[librarymanagement] abstract class ResolverFunctions {
       mavenCentral: Boolean
   ): Vector[Resolver] =
     Vector(Resolver.defaultLocal) ++
+      userResolvers ++
       single(DefaultMavenRepository, mavenCentral)
 
   /**
diff --git a/lm-core/src/test/scala/sbt/librarymanagement/ResolverExtraTest.scala b/lm-core/src/test/scala/sbt/librarymanagement/ResolverExtraTest.scala
index 57b407c8a..3dc63539f 100644
--- a/lm-core/src/test/scala/sbt/librarymanagement/ResolverExtraTest.scala
+++ b/lm-core/src/test/scala/sbt/librarymanagement/ResolverExtraTest.scala
@@ -1,50 +1,69 @@
 package sbt.librarymanagement
 
-import verify.BasicTestSuite
+import hedgehog.*
+import hedgehog.runner.*
 import scala.annotation.nowarn
 
 @nowarn // Necessary because our test cases look like interpolated strings.
-object ResolverExtraTest extends BasicTestSuite {
-  test("expandMavenSettings should expand existing environment variables") {
-    assertExpansion(
-      input = "User home: ${env.HOME}",
-      expected = s"User home: ${env("HOME")}"
+object ResolverExtraTest extends Properties:
+  override def tests: List[Test] = List(
+    example(
+      "expandMavenSettings should expand existing environment variables",
+      assertExpansion(
+        input = "User home: ${env.HOME}",
+        expected = s"User home: ${env("HOME")}"
+      )
+    ),
+    example(
+      "expandMavenSettings should expand existing system properties",
+      assertExpansion(
+        input = "User dir: ${user.dir}",
+        expected = s"User dir: ${prop("user.dir")}"
+      )
+    ),
+    example(
+      "expandMavenSettings should expand unknown system properties to the empty string",
+      assertExpansion(
+        input = "Unknown system property: ${IF_THIS_EXISTS_WE_NEED_TO_HAVE_A_CHAT}",
+        expected = s"Unknown system property: "
+      )
+    ),
+    example(
+      "expandMavenSettings should expand unknown environment variables to the empty string",
+      assertExpansion(
+        input = "Unknown environment variable: ${IF_THIS_EXISTS_I_WORRY_ABOUT_YOU}",
+        expected = s"Unknown environment variable: "
+      )
+    ),
+    example(
+      "expandMavenSettings should preserve backslashes in environment variable values", {
+        val path = """C:\foo\bar\baz"""
+        val env = Map("SOME_PATH" -> path)
+
+        Result.assert(Resolver.expandMavenSettings("${env.SOME_PATH}", env) == path)
+      }
+    ),
+    property("combineDefaultResolvers preserves the input resolvers", propPreserve)
+  )
+
+  def gen[A1: Gen]: Gen[A1] = summon[Gen[A1]]
+
+  given Gen[Resolver] = Gen.frequency1(
+    1 -> Gen.constant(Resolver.file("/tmp/foo")),
+    1 -> Gen.constant(Resolver.mavenLocal),
+  )
+
+  def propPreserve: Property =
+    for r <- gen[Resolver].forAll
+    yield Result.assert(
+      Resolver.combineDefaultResolvers(Vector(r)).contains(r)
     )
-  }
-
-  test("expandMavenSettings should expand existing system properties") {
-    assertExpansion(
-      input = "User dir: ${user.dir}",
-      expected = s"User dir: ${prop("user.dir")}"
-    )
-  }
-
-  test("expandMavenSettings should expand unknown system properties to the empty string") {
-    assertExpansion(
-      input = "Unknown system property: ${IF_THIS_EXISTS_WE_NEED_TO_HAVE_A_CHAT}",
-      expected = s"Unknown system property: "
-    )
-  }
-
-  test("expandMavenSettings should expand unknown environment variables to the empty string") {
-    assertExpansion(
-      input = "Unknown environment variable: ${IF_THIS_EXISTS_I_WORRY_ABOUT_YOU}",
-      expected = s"Unknown environment variable: "
-    )
-  }
-
-  test("expandMavenSettings should preserve backslashes in environment variable values") {
-    val path = """C:\foo\bar\baz"""
-    val env = Map("SOME_PATH" -> path)
-
-    assert(Resolver.expandMavenSettings("${env.SOME_PATH}", env) == path)
-  }
 
   // - Helper functions ----------------------------------------------------------------------------
   // -----------------------------------------------------------------------------------------------
-  def assertExpansion(input: String, expected: String) =
-    Predef.assert(Resolver.expandMavenSettings(input) == s"$expected")
+  inline def assertExpansion(input: String, expected: String) =
+    Result.assert(Resolver.expandMavenSettings(input) == s"$expected")
 
   def env(name: String) = sys.env.getOrElse(name, "")
   def prop(name: String) = sys.props.getOrElse(name, "")
-}
+end ResolverExtraTest