Add rewrite rule for var x: T = _

scala · Nov 2, 2023 · 0343a75 · 0343a75
1 parent a825cf9
commit 0343a75
Show file tree

Hide file tree

Showing 5 changed files with 9 additions and 1 deletion.
diff --git a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
@@ -3656,9 +3656,11 @@ object Parsers {
                 && !tpt.isEmpty && mods.is(Mutable) && lhs.forall(_.isInstanceOf[Ident]) =>
               report.errorOrMigrationWarning(
                 em"""`= _` has been deprecated; use `= uninitialized` instead.
-                        |`uninitialized` can be imported with `scala.compiletime.uninitialized`.""",
+                        |`uninitialized` can be imported with `scala.compiletime.uninitialized`.${rewriteNotice(`future-migration`)}""",
                 in.sourcePos(rhsOffset),
                 from = future)
+              if sourceVersion == `future-migration` then
+                patch(source, Span(rhsOffset, rhsOffset + 1), "scala.compiletime.uninitialized")
               placeholderParams = placeholderParams.tail
               atSpan(rhs0.span) { Ident(nme.WILDCARD) }
             case rhs0 => rhs0

diff --git a/compiler/test/dotty/tools/dotc/CompilationTests.scala b/compiler/test/dotty/tools/dotc/CompilationTests.scala
@@ -60,6 +60,7 @@ class CompilationTests {
       compileFile("tests/rewrites/rewrites.scala", defaultOptions.and("-source", "3.0-migration").and("-rewrite", "-indent")),
       compileFile("tests/rewrites/rewrites3x.scala", defaultOptions.and("-rewrite", "-source", "future-migration")),
       compileFile("tests/rewrites/rewrites3x-fatal-warnings.scala", defaultOptions.and("-rewrite", "-source", "future-migration", "-Xfatal-warnings")),
+      compileFile("tests/rewrites/uninitialized-var.scala", defaultOptions.and("-rewrite", "-source", "future-migration")),
       compileFile("tests/rewrites/with-type-operator.scala", defaultOptions.and("-rewrite", "-source", "future-migration")),
       compileFile("tests/rewrites/filtering-fors.scala", defaultOptions.and("-rewrite", "-source", "3.2-migration")),
       compileFile("tests/rewrites/refutable-pattern-bindings.scala", defaultOptions.and("-rewrite", "-source", "3.2-migration")),

diff --git a/tests/neg/uninitialized-future-migration.check b/tests/neg/uninitialized-future-migration.check
@@ -3,3 +3,4 @@
   |               ^
   |               `= _` has been deprecated; use `= uninitialized` instead.
   |               `uninitialized` can be imported with `scala.compiletime.uninitialized`.
+  |               This construct can be rewritten automatically under -rewrite -source future-migration.
diff --git a/tests/rewrites/uninitialized-var.check b/tests/rewrites/uninitialized-var.check
@@ -0,0 +1,2 @@
+class Foo:
+  var a: Int = scala.compiletime.uninitialized
diff --git a/tests/rewrites/uninitialized-var.scala b/tests/rewrites/uninitialized-var.scala
@@ -0,0 +1,2 @@
+class Foo:
+  var a: Int = _