Deprecation warnings for old syntax: with as a type operator (#18837)

This is the first part of #18868

community-build/src/scala/dotty/communitybuild/projects.scala

@@ -404,7 +404,7 @@ object projects:
     project = "zio",
     sbtTestCommand = "testJVMDotty",
     sbtDocCommand = forceDoc("coreJVM"),
-    scalacOptions = SbtCommunityProject.scalacOptions.filter(_ != "-Xcheck-macros"),
+    scalacOptions = "-source" :: "3.3" :: SbtCommunityProject.scalacOptions.filter(_ != "-Xcheck-macros"),
     dependencies =List(izumiReflect)
   )
 

compiler/src/dotty/tools/dotc/parsing/Parsers.scala

@@ -1757,11 +1757,12 @@ object Parsers {
           t
         else
           val withSpan = Span(withOffset, withOffset + 4)
-          report.errorOrMigrationWarning(
-            DeprecatedWithOperator(rewriteNotice(`future-migration`)),
+          report.gradualErrorOrMigrationWarning(
+            DeprecatedWithOperator(rewriteNotice(`3.4-migration`)),
             source.atSpan(withSpan),
-            from = future)
-          if sourceVersion == `future-migration` then
+            warnFrom = `3.4`,
+            errorFrom = future)
+          if sourceVersion.isMigrating && sourceVersion.isAtLeast(`3.4-migration`) then
             patch(source, withSpan, "&")
           atSpan(startOffset(t)) { makeAndType(t, withType()) }
       else t

compiler/test-resources/repl/i6643

@@ -1,7 +1,12 @@
 scala> import scala.collection._
-
 scala>:type 1
 Int
-
 scala> object IterableTest { def g[CC[_] <: Iterable[_] with IterableOps[_, _, _]](from: CC[Int]): IterableFactory[CC] = ??? }
+1 warning found
+-- [E003] Syntax Warning: ------------------------------------------------------
+1 | object IterableTest { def g[CC[_] <: Iterable[_] with IterableOps[_, _, _]](from: CC[Int]): IterableFactory[CC] = ??? }
+  |                                                  ^^^^
+  |                with as a type operator has been deprecated; use & instead
+  |
+  | longer explanation available when compiling with `-explain`
 // defined object IterableTest

compiler/test-resources/type-printer/infix

@@ -48,10 +48,31 @@ def foo: Int && Boolean & String
 scala> def foo: Int && (Boolean & String) = ???
 def foo: Int && (Boolean & String)
 scala> def foo: Int && (Boolean with String) = ???
+1 warning found
+-- [E003] Syntax Warning: ------------------------------------------------------
+1 | def foo: Int && (Boolean with String) = ???
+  |                          ^^^^
+  |                with as a type operator has been deprecated; use & instead
+  |
+  | longer explanation available when compiling with `-explain`
 def foo: Int && (Boolean & String)
 scala> def foo: (Int && Boolean) with String = ???
+1 warning found
+-- [E003] Syntax Warning: ------------------------------------------------------
+1 | def foo: (Int && Boolean) with String = ???
+  |                           ^^^^
+  |                with as a type operator has been deprecated; use & instead
+  |
+  | longer explanation available when compiling with `-explain`
 def foo: Int && Boolean & String
 scala> def foo: Int && Boolean with String = ???
+1 warning found
+-- [E003] Syntax Warning: ------------------------------------------------------
+1 | def foo: Int && Boolean with String = ???
+  |                         ^^^^
+  |                with as a type operator has been deprecated; use & instead
+  |
+  | longer explanation available when compiling with `-explain`
 def foo: Int && (Boolean & String)
 scala> def foo: Int && Boolean | String = ???
 def foo: Int && Boolean | String

tests/neg-scalajs/js-native-members.check

@@ -28,6 +28,13 @@
    |                         The [this] qualifier will be deprecated in the future; it should be dropped.
    |                         See: https://docs.scala-lang.org/scala3/reference/dropped-features/this-qualifier.html
    |                         This construct can be rewritten automatically under -rewrite -source 3.4-migration.
+-- [E003] Syntax Warning: tests/neg-scalajs/js-native-members.scala:58:44 ----------------------------------------------
+58 |  def assign[T, U](target: T, source: U): T with U = js.native // ok
+   |                                            ^^^^
+   |                             with as a type operator has been deprecated; use & instead
+   |                             This construct can be rewritten automatically under -rewrite -source 3.4-migration.
+   |
+   | longer explanation available when compiling with `-explain`
 -- Error: tests/neg-scalajs/js-native-members.scala:9:24 ---------------------------------------------------------------
 9 |  def this(z: String) = this(z.length, z) // error
   |                        ^^^^^^^^^^^^^^^^^

tests/neg-scalajs/jsconstructorof-error-in-prepjsinterop.check

@@ -1,3 +1,17 @@
+-- [E003] Syntax Warning: tests/neg-scalajs/jsconstructorof-error-in-prepjsinterop.scala:16:41 -------------------------
+16 |  val c = js.constructorOf[NativeJSClass with NativeJSTrait] // error
+   |                                         ^^^^
+   |                             with as a type operator has been deprecated; use & instead
+   |                             This construct can be rewritten automatically under -rewrite -source 3.4-migration.
+   |
+   | longer explanation available when compiling with `-explain`
+-- [E003] Syntax Warning: tests/neg-scalajs/jsconstructorof-error-in-prepjsinterop.scala:22:35 -------------------------
+22 |  val g = js.constructorOf[JSClass with JSTrait] // error
+   |                                   ^^^^
+   |                             with as a type operator has been deprecated; use & instead
+   |                             This construct can be rewritten automatically under -rewrite -source 3.4-migration.
+   |
+   | longer explanation available when compiling with `-explain`
 -- Error: tests/neg-scalajs/jsconstructorof-error-in-prepjsinterop.scala:13:27 -----------------------------------------
 13 |  val a = js.constructorOf[NativeJSTrait] // error
    |                           ^^^^^^^^^^^^^

tests/neg-scalajs/jsconstructortag-error-in-prepjsinterop.check

@@ -1,3 +1,17 @@
+-- [E003] Syntax Warning: tests/neg-scalajs/jsconstructortag-error-in-prepjsinterop.scala:16:42 ------------------------
+16 |  val c = js.constructorTag[NativeJSClass with NativeJSTrait] // error
+   |                                          ^^^^
+   |                             with as a type operator has been deprecated; use & instead
+   |                             This construct can be rewritten automatically under -rewrite -source 3.4-migration.
+   |
+   | longer explanation available when compiling with `-explain`
+-- [E003] Syntax Warning: tests/neg-scalajs/jsconstructortag-error-in-prepjsinterop.scala:22:36 ------------------------
+22 |  val g = js.constructorTag[JSClass with JSTrait] // error
+   |                                    ^^^^
+   |                             with as a type operator has been deprecated; use & instead
+   |                             This construct can be rewritten automatically under -rewrite -source 3.4-migration.
+   |
+   | longer explanation available when compiling with `-explain`
 -- Error: tests/neg-scalajs/jsconstructortag-error-in-prepjsinterop.scala:13:42 ----------------------------------------
 13 |  val a = js.constructorTag[NativeJSTrait] // error
    |                                          ^

tests/neg/i2887b.scala

@@ -4,7 +4,7 @@ trait C { type M <: B }
 trait D { type M >: A }
 
 object Test {
-  def test(x: C with D): Unit = {
+  def test(x: C & D): Unit = {
     def foo(a: A, b: B)(z: a.S[b.I,a.I][b.S[a.I,a.I]]) = z
     def bar(a: A, y: x.M) = foo(a,y)
     def baz(a: A) = bar(a, a)

tests/neg/i8736.scala

@@ -14,13 +14,13 @@ object App extends App {
   def field[V](s: String)(v: V): Rec[s.type, V] = Rec0(Map(s -> v)).asInstanceOf[Rec[s.type, V]]
 
   implicit class RecOps[R <: Rec0[_]](has: R) {
-    def +[K1 <: String, V1](that: Rec[K1, V1]): R with Rec[K1, V1] = Rec0(has.map ++ that.map).asInstanceOf[R with Rec[K1, V1]]
+    def +[K1 <: String, V1](that: Rec[K1, V1]): R & Rec[K1, V1] = Rec0(has.map ++ that.map).asInstanceOf[R & Rec[K1, V1]]
   }
 
   def rec:
     Rec["k", String]
-      with Rec["v", Int]
-      with Rec["z", Boolean]
+      & Rec["v", Int]
+      & Rec["z", Boolean]
     = {
     field("k")("Str") +
       field("v")(0) +

tests/neg/with-type-operator-future-migration.check

@@ -2,6 +2,6 @@
 5 |def foo: Int with String = ??? // error
   |             ^^^^
   |             with as a type operator has been deprecated; use & instead
-  |             This construct can be rewritten automatically under -rewrite -source future-migration.
+  |             This construct can be rewritten automatically under -rewrite -source 3.4-migration.
   |
   | longer explanation available when compiling with `-explain`

tests/pos-deep-subtype/3324h.scala

@@ -1,5 +1,7 @@
 //> using options -Xfatal-warnings
 
+import scala.language.`3.3`
+
 object Test {
   trait Marker
   def foo[T](x: T) = x match {
@@ -8,7 +10,7 @@ object Test {
   }
 
   def foo2[T](x: T) = x match {
-    case _: T with Marker      => // scalac emits a warning
+    case _: T with Marker      => // scalac or 3.4 emits a warning
     case _ =>
   }
 }

tests/pos/with-type-operator-3.3.scala

@@ -0,0 +1,5 @@
+//> using options -Werror
+
+import scala.language.`3.3`
+
+def foo: Int with String = ???

tests/pos/with-type-operator.scala → tests/pos/with-type-operator-3.4-migration.scala

@@ -1,3 +1,3 @@
-//> using options -Werror
+import scala.language.`3.4-migration`
 
 def foo: Int with String = ??? // warn

tests/semanticdb/metac.expect

@@ -3394,6 +3394,7 @@ Text => empty
 Language => Scala
 Symbols => 13 entries
 Occurrences => 22 entries
+Diagnostics => 1 entries
 
 Symbols:
 local0 => selfparam self: C1
@@ -3434,6 +3435,10 @@ Occurrences:
 [13:17..13:17): <- selfs/C6#`<init>`().
 [13:27..13:28): B -> selfs/B#
 
+Diagnostics:
+[10:29..10:33): [warning] with as a type operator has been deprecated; use & instead
+This construct can be rewritten automatically under -rewrite -source 3.4-migration.
+
 expect/StructuralTypes.scala
 ----------------------------
 
@@ -5059,7 +5064,7 @@ Text => empty
 Language => Scala
 Symbols => 143 entries
 Occurrences => 246 entries
-Diagnostics => 1 entries
+Diagnostics => 3 entries
 Synthetics => 1 entries
 
 Symbols:
@@ -5457,6 +5462,10 @@ Occurrences:
 
 Diagnostics:
 [5:13..5:14): [warning] unused explicit parameter
+[62:25..62:29): [warning] with as a type operator has been deprecated; use & instead
+This construct can be rewritten automatically under -rewrite -source 3.4-migration.
+[63:25..63:29): [warning] with as a type operator has been deprecated; use & instead
+This construct can be rewritten automatically under -rewrite -source 3.4-migration.
 
 Synthetics:
 [68:20..68:24):@ann => *[Int]