Merge pull request #5240 from dotty-staging/fix/constructor-fixes

Fix go to definition on constructor calls

Author: Duhemm

compiler/src/dotty/tools/dotc/interactive/Interactive.scala

@@ -76,6 +76,10 @@ object Interactive {
           }.getOrElse(fn.symbol)
         }
 
+      // For constructor calls, return the `<init>` that was selected
+      case _ :: (_:  New) :: (select: Select) :: _ =>
+        select.symbol
+
       case _ =>
         enclosingTree(path).symbol
     }

compiler/src/dotty/tools/dotc/interactive/SourceTree.scala

@@ -21,7 +21,11 @@ case class SourceTree(tree: tpd.NameTree, source: SourceFile) {
     if (treePos.isZeroExtent || tree.name.toTermName == nme.ERROR)
       NoSourcePosition
     else {
-      val nameLength = tree.name.stripModuleClassSuffix.show.toString.length
+      // Constructors are named `<init>` in the trees, but `this` in the source.
+      val nameLength = tree.name match {
+        case nme.CONSTRUCTOR => nme.this_.toString.length
+        case other => other.stripModuleClassSuffix.show.toString.length
+      }
       val position = {
         // FIXME: This is incorrect in some cases, like with backquoted identifiers,
         //        see https://github.com/lampepfl/dotty/pull/1634#issuecomment-257079436

language-server/test/dotty/tools/languageserver/DefinitionTest.scala

@@ -19,6 +19,24 @@ class DefinitionTest {
       .definition(m5 to m6, List(m1 to m2))
   }
 
+  @Test def caseClassDefinition0: Unit = {
+    withSources(
+      code"""case class ${m1}Foo${m2}(x: String) {
+              def ${m3}this${m4}(x: Int) = ${m5}this${m6}(x.toString)
+             }""",
+      code"""class Bar {
+               val foo: ${m7}Foo${m8} = ${m9}Foo${m10}("hello")
+               val bar: ${m11}Foo${m12} = new ${m13}Foo${m14}(2)
+             }"""
+    ) .definition(m1 to m2, List(m1 to m2))
+      .definition(m3 to m4, List(m3 to m4))
+      .definition(m5 to m6, List(m1 to m2))
+      .definition(m7 to m8, List(m1 to m2))
+      .definition(m9 to m10, List(m1 to m2))
+      .definition(m11 to m12, List(m1 to m2))
+      .definition(m13 to m14, List(m3 to m4))
+  }
+
   @Test def valDefinition0: Unit = {
     withSources(
       code"class Foo { val ${m1}x$m2 = 0; ${m3}x$m4 }",
@@ -134,6 +152,18 @@ class DefinitionTest {
       .definition(m11 to m12, List(m1 to m2))
   }
 
+  @Test def goToParamApply: Unit = {
+    withSources(
+      code"""case class Foo(${m1}x${m2}: Int, ${m3}y${m4}: String)""",
+      code"""object Bar {
+               Foo(${m5}x${m6} = 1, ${m7}y${m8} = "hello")
+             }"""
+    ) .definition(m1 to m2, List(m1 to m2))
+      .definition(m3 to m4, List(m3 to m4))
+      .definition(m5 to m6, List(m1 to m2))
+      .definition(m7 to m8, List(m3 to m4))
+  }
+
   @Test def goToParamCopyMethod: Unit = {
 
     withSources(
@@ -148,4 +178,15 @@ class DefinitionTest {
       .definition(m9 to m10, List(m3 to m4))
   }
 
+  @Test def constructorDefinition: Unit = {
+    withSources(
+      code"class ${m1}A${m2}(x: Boolean) { def ${m3}this${m4}(x: Int) = ${m5}this${m6}(x > 0) }",
+      code"object B { val a0 = new ${m7}A${m8}(true); val a1 = new ${m9}A${m10}(0) }"
+    ) .definition(m1 to m2, List(m1 to m2))
+      .definition(m3 to m4, List(m3 to m4))
+      .definition(m5 to m6, List(m1 to m2))
+      .definition(m7 to m8, List(m1 to m2))
+      .definition(m9 to m10, List(m3 to m4))
+  }
+
 }