Take into account classifiers specified via attributes in Ivy repos

core/shared/src/main/scala/coursier/ivy/IvyRepository.scala

@@ -73,13 +73,32 @@ final case class IvyRepository(
           val retained =
             overrideClassifiers match {
               case None =>
-                project.publications.collect {
-                  case (conf, p)
-                    if conf == "*" ||
-                       conf == dependency.configuration ||
-                       project.allConfigurations.getOrElse(dependency.configuration, Set.empty).contains(conf) =>
-                    p
-                }
+
+                // FIXME Some duplication with what's done in MavenSource
+
+                if (dependency.attributes.classifier.nonEmpty)
+                  // FIXME We're ignoring dependency.attributes.`type` in this case
+                  project.publications.collect {
+                    case (_, p) if p.classifier == dependency.attributes.classifier =>
+                      p
+                  }
+                else if (dependency.attributes.`type`.nonEmpty)
+                  project.publications.collect {
+                    case (_, p)
+                      if p.classifier.isEmpty && (
+                        p.`type` == dependency.attributes.`type` ||
+                          (p.ext == dependency.attributes.`type` && project.packagingOpt.toSeq.contains(p.`type`)) // wow
+                        ) =>
+                      p
+                  }
+                else
+                  project.publications.collect {
+                    case (conf, p)
+                      if conf == "*" ||
+                         conf == dependency.configuration ||
+                         project.allConfigurations.getOrElse(dependency.configuration, Set.empty).contains(conf) =>
+                      p
+                  }
               case Some(classifiers) =>
                 val classifiersSet = classifiers.toSet
                 project.publications.collect {

sbt-coursier/src/sbt-test/sbt-coursier/tests-classifier/a/src/main/scala/a/A.scala

@@ -0,0 +1,3 @@
+package a
+
+object A { val value = 42 }

sbt-coursier/src/sbt-test/sbt-coursier/tests-classifier/a/src/test/scala/a/ATest.scala

@@ -0,0 +1,3 @@
+package a
+
+object ATest { val value = 43 }

sbt-coursier/src/sbt-test/sbt-coursier/tests-classifier/b/src/main/scala/b/B.scala

@@ -0,0 +1,3 @@
+package b
+
+object B { val value = a.A.value }

sbt-coursier/src/sbt-test/sbt-coursier/tests-classifier/b/src/test/scala/b/BTest.scala

@@ -0,0 +1,3 @@
+package a
+
+object BTest { val value = a.ATest.value }

sbt-coursier/src/sbt-test/sbt-coursier/tests-classifier/build.sbt

@@ -0,0 +1,22 @@
+
+val org = "io.get-coursier.tests"
+val nme = "coursier-test-a"
+val ver = "0.1-SNAPSHOT"
+
+lazy val a = project
+  .settings(
+    organization := org,
+    name := nme,
+    publishArtifact.in(Test) := true,
+    version := ver
+  )
+
+lazy val b = project
+  .settings(
+    classpathTypes += "test-jar",
+    libraryDependencies ++= Seq(
+      org %% nme % ver,
+      org %% nme % ver % "test" classifier "tests"
+    )
+  )
+

sbt-coursier/src/sbt-test/sbt-coursier/tests-classifier/project/plugins.sbt

@@ -0,0 +1,11 @@
+{
+  val pluginVersion = sys.props.getOrElse(
+    "plugin.version",
+    throw new RuntimeException(
+      """|The system property 'plugin.version' is not defined.
+         |Specify this property using the scriptedLaunchOpts -D.""".stripMargin
+    )
+  )
+
+  addSbtPlugin("io.get-coursier" % "sbt-coursier" % pluginVersion)
+}

sbt-coursier/src/sbt-test/sbt-coursier/tests-classifier/test

@@ -0,0 +1,2 @@
+> a/publishLocal
+> b/test

tests/jvm/src/test/scala/coursier/test/IvyTests.scala

@@ -70,7 +70,7 @@ object IvyTests extends TestSuite {
       val mainJarUrl = repoBase + "com.example/a_2.11/0.1.0-SNAPSHOT/jars/a_2.11.jar"
       val testJarUrl = repoBase + "com.example/a_2.11/0.1.0-SNAPSHOT/jars/a_2.11-tests.jar"
 
-      * - CentralTests.withArtifacts(
+      "no conf or classifier" - CentralTests.withArtifacts(
         dep = dep,
         artifactType = "jar",
         extraRepos = Seq(repo),
@@ -83,7 +83,7 @@ object IvyTests extends TestSuite {
           throw new Exception(s"Unexpected number of artifacts\n${other.mkString("\n")}")
       }
 
-      * - CentralTests.withArtifacts(
+      "test conf" - CentralTests.withArtifacts(
         dep = dep.copy(configuration = "test"),
         artifactType = "jar",
         extraRepos = Seq(repo),
@@ -99,6 +99,40 @@ object IvyTests extends TestSuite {
         case other =>
           throw new Exception(s"Unexpected number of artifacts\n${other.mkString("\n")}")
       }
+
+      "tests classifier" - {
+        val testsDep = dep.copy(attributes = Attributes("jar", "tests"))
+
+        * - CentralTests.withArtifacts(
+          deps = Set(dep, testsDep),
+          artifactType = "jar",
+          extraRepos = Seq(repo),
+          classifierOpt = None,
+          optional = true
+        ) {
+          case Seq(artifact1, artifact2) =>
+            val urls = Set(
+              artifact1.url,
+              artifact2.url
+            )
+            assert(urls == Set(mainJarUrl, testJarUrl))
+          case other =>
+            throw new Exception(s"Unexpected number of artifacts\n${other.mkString("\n")}")
+        }
+
+        * - CentralTests.withArtifacts(
+          dep = testsDep,
+          artifactType = "jar",
+          extraRepos = Seq(repo),
+          classifierOpt = None,
+          optional = true
+        ) {
+          case Seq(artifact) =>
+            assert(artifact.url == testJarUrl)
+          case other =>
+            throw new Exception(s"Unexpected number of artifacts\n${other.mkString("\n")}")
+        }
+      }
     }
   }