(REF): initial support for rename refactoring

closes #575

Author: matklad

src/main/kotlin/org/rust/lang/core/grammar/rust.bnf

@@ -515,7 +515,8 @@ alias ::= AS IDENTIFIER
 
 extern_crate_item ::= attrs_and_vis EXTERN CRATE IDENTIFIER alias? ';' {
   hooks = [ leftBinder = "DOC_COMMENT_BINDER" ]
-  implements = [ "org.rust.lang.core.psi.RustNamedElement"
+  implements = [ "org.rust.lang.core.psi.RustReferenceElement"
+                 "org.rust.lang.core.psi.RustNamedElement"
                  "org.rust.lang.core.psi.RustItemElement" ]
 }
 
@@ -525,7 +526,8 @@ extern_crate_item ::= attrs_and_vis EXTERN CRATE IDENTIFIER alias? ';' {
 
 mod_decl_item ::= attrs_and_vis MOD IDENTIFIER ';' {
   hooks = [ leftBinder = "DOC_COMMENT_BINDER" ]
-  implements = [ "org.rust.lang.core.psi.RustNamedElement"
+  implements = [ "org.rust.lang.core.psi.RustReferenceElement"
+                 "org.rust.lang.core.psi.RustNamedElement"
                  "org.rust.lang.core.psi.RustItemElement" ]
   stubClass = "org.rust.lang.core.stubs.elements.RustModDeclElementItemStub"
   elementTypeFactory = "org.rust.lang.core.stubs.ElementFactoryKt.factory"

src/main/kotlin/org/rust/lang/core/psi/RustElementFactory.kt

@@ -1,6 +1,7 @@
 package org.rust.lang.core.psi
 
 import com.intellij.openapi.project.Project
+import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFileFactory
 import org.rust.lang.RustLanguage
 import org.rust.lang.core.psi.util.childOfType
@@ -35,6 +36,9 @@ object RustElementFactory {
         return createFromText(project, "impl T for S { $methods }")
     }
 
+    fun createIdentifier(project: Project, name: String): PsiElement =
+        createFromText<RustModDeclItemElement>(project, "mod $name;")!!.identifier
+
     private inline fun <reified T : RustCompositeElement> createFromText(project: Project, code: String): T? =
         PsiFileFactory.getInstance(project)
             .createFileFromText("DUMMY.rs", RustLanguage, code)

src/main/kotlin/org/rust/lang/core/psi/impl/RustNamedElementImpl.kt

@@ -2,6 +2,7 @@ package org.rust.lang.core.psi.impl
 
 import com.intellij.lang.ASTNode
 import com.intellij.psi.PsiElement
+import org.rust.lang.core.psi.RustElementFactory
 import org.rust.lang.core.psi.RustNamedElement
 import org.rust.lang.core.psi.RustTokenElementTypes
 
@@ -13,11 +14,9 @@ abstract class RustNamedElementImpl(node: ASTNode)   : RustCompositeElementImpl(
 
     override fun getName(): String? = nameElement?.text
 
-    /**
-     * NOTE: This is orphaned purposefully
-     */
     override fun setName(name: String): PsiElement? {
-        throw UnsupportedOperationException()
+        nameElement?.replace(RustElementFactory.createIdentifier(project, name))
+        return this
     }
 
     override fun getNavigationElement(): PsiElement = nameElement ?: this

src/main/kotlin/org/rust/lang/core/psi/impl/RustStubbedNamedElementImpl.kt

@@ -5,6 +5,7 @@ import com.intellij.lang.ASTNode
 import com.intellij.navigation.ItemPresentation
 import com.intellij.psi.PsiElement
 import com.intellij.psi.stubs.IStubElementType
+import org.rust.lang.core.psi.RustElementFactory
 import org.rust.lang.core.psi.RustNamedElement
 import org.rust.lang.core.psi.RustTokenElementTypes
 import org.rust.lang.core.stubs.RustNamedElementStub
@@ -26,8 +27,8 @@ abstract class RustStubbedNamedElementImpl<StubT> : RustStubbedElementImpl<StubT
     }
 
     override fun setName(name: String): PsiElement? {
-        // sic!
-        throw UnsupportedOperationException()
+        nameElement?.replace(RustElementFactory.createIdentifier(project, name))
+        return this
     }
 
     override fun getNavigationElement(): PsiElement = nameElement ?: this

src/main/kotlin/org/rust/lang/core/psi/impl/mixin/RustExternCrateItemImplMixin.kt

@@ -1,6 +1,7 @@
 package org.rust.lang.core.psi.impl.mixin
 
 import com.intellij.lang.ASTNode
+import com.intellij.psi.PsiElement
 import org.rust.lang.core.psi.RustExternCrateItemElement
 import org.rust.lang.core.psi.impl.RustNamedElementImpl
 import org.rust.lang.core.psi.impl.RustPsiImplUtil
@@ -12,5 +13,7 @@ abstract class RustExternCrateItemImplMixin(node: ASTNode) : RustNamedElementImp
 
     override fun getReference(): RustReference = RustExternCrateReferenceImpl(this)
 
+    override val referenceNameElement: PsiElement get() = identifier
+
     override val isPublic: Boolean get() = RustPsiImplUtil.isPublicNonStubbed(this)
 }

src/main/kotlin/org/rust/lang/core/psi/impl/mixin/RustModDeclItemImplMixin.kt

@@ -2,6 +2,7 @@ package org.rust.lang.core.psi.impl.mixin
 
 
 import com.intellij.lang.ASTNode
+import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFile
 import com.intellij.psi.stubs.IStubElementType
 import org.rust.ide.icons.RustIcons
@@ -24,14 +25,16 @@ abstract class RustModDeclItemImplMixin : RustStubbedNamedElementImpl<RustModDec
 
     override fun getReference(): RustReference = RustModReferenceImpl(this)
 
+    override val referenceNameElement: PsiElement get() = identifier
+
     override fun getIcon(flags: Int): Icon? = iconWithVisibility(flags, RustIcons.MODULE)
 
     override val isPublic: Boolean get() = RustPsiImplUtil.isPublic(this)
 
 }
 
 fun RustModDeclItemElement.getOrCreateModuleFile(): PsiFile? {
-    return  reference!!.resolve()?.let { it.containingFile } ?:
+    return  reference.resolve()?.containingFile ?:
             containingMod?.ownedDirectory?.createFile(suggestChildFileName ?: return null)
 }
 

src/main/kotlin/org/rust/lang/core/resolve/ref/RustFieldExprReferenceImpl.kt

@@ -16,4 +16,9 @@ class RustFieldExprReferenceImpl(
 
     override fun resolveVerbose(): RustResolveEngine.ResolveResult =
         RustResolveEngine.resolveFieldExpr(element)
+
+    override fun handleElementRename(newName: String): PsiElement {
+        element.fieldId.identifier?.let { doRename(it, newName) }
+        return element
+    }
 }

src/main/kotlin/org/rust/lang/core/resolve/ref/RustReferenceBase.kt

@@ -4,12 +4,15 @@ import com.intellij.openapi.util.TextRange
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiReferenceBase
 import com.intellij.psi.impl.source.resolve.ResolveCache
-import org.rust.lang.core.psi.RustCompositeElement
+import org.rust.lang.core.psi.RustElementFactory
 import org.rust.lang.core.psi.RustNamedElement
+import org.rust.lang.core.psi.RustReferenceElement
+import org.rust.lang.core.psi.RustTokenElementTypes
+import org.rust.lang.core.psi.util.elementType
 import org.rust.lang.core.psi.util.parentRelativeRange
 import org.rust.lang.core.resolve.RustResolveEngine
 
-abstract class RustReferenceBase<T : RustCompositeElement>(
+abstract class RustReferenceBase<T : RustReferenceElement>(
     element: T
 ) : PsiReferenceBase<T>(element)
   , RustReference {
@@ -40,6 +43,11 @@ abstract class RustReferenceBase<T : RustCompositeElement>(
         return element.referenceAnchor.parentRelativeRange
     }
 
+    override fun handleElementRename(newName: String): PsiElement {
+        doRename(element.referenceNameElement, newName)
+        return element
+    }
+
     val cache = ResolveCache.getInstance(element.project)
 
     private fun cache(block: (RustReferenceBase<T>, Boolean) -> RustResolveEngine.ResolveResult): RustResolveEngine.ResolveResult =
@@ -49,4 +57,11 @@ abstract class RustReferenceBase<T : RustCompositeElement>(
             false /* needToPreventRecursion = */ ,
             false /* incompleteCode = */
         ) ?: RustResolveEngine.ResolveResult.Unresolved
+
+    companion object {
+        @JvmStatic protected fun doRename(identifier: PsiElement, newName: String) {
+            check(identifier.elementType == RustTokenElementTypes.IDENTIFIER)
+            identifier.replace(RustElementFactory.createIdentifier(identifier.project, newName))
+        }
+    }
 }

src/main/kotlin/org/rust/lang/core/stubs/index/RustModulesIndex.kt

@@ -28,7 +28,7 @@ class RustModulesIndex : StringStubIndexExtension<RustModDeclItemElement>() {
             StubIndex.getInstance().processElements(
                 KEY, key, project, GlobalSearchScope.allScope(project), RustModDeclItemElement::class.java
             ) { modDecl ->
-                if (modDecl.reference?.resolve() == mod) {
+                if (modDecl.reference.resolve() == mod) {
                     result = modDecl.containingMod
                     false
                 } else {

src/test/kotlin/org/rust/ide/refactoring/RenameTest.kt

@@ -0,0 +1,17 @@
+package org.rust.ide.refactoring
+
+import org.rust.lang.RustTestCaseBase
+
+class RenameTest: RustTestCaseBase() {
+    override val dataPath = "org/rust/ide/refactoring/fixtures/rename"
+
+    fun testFunction() = doTest()
+    fun testField() = doTest()
+
+    private fun doTest(name: String = "spam") {
+        myFixture.configureByFile(fileName)
+        myFixture.renameElementAtCaret(name)
+        myFixture.checkResultByFile(fileName, fileName.replace(".rs", "_after.rs"), false);
+    }
+}
+