Introduce line marker for wasm_bindgen attributes

Author: avrong

js/src/main/kotlin/org/rust/js/RsWasmBindgenLineMarkerProvider.kt

@@ -0,0 +1,102 @@
+/*
+ * Use of this source code is governed by the MIT license that can be
+ * found in the LICENSE file.
+ */
+
+package org.rust.js
+
+import com.intellij.codeInsight.daemon.DefaultGutterIconNavigationHandler
+import com.intellij.codeInsight.daemon.RelatedItemLineMarkerInfo
+import com.intellij.codeInsight.daemon.RelatedItemLineMarkerProvider
+import com.intellij.lang.javascript.psi.JSElement
+import com.intellij.lang.javascript.psi.ecma6.TypeScriptClass
+import com.intellij.lang.javascript.psi.ecma6.TypeScriptEnum
+import com.intellij.lang.javascript.psi.ecma6.TypeScriptFunction
+import com.intellij.navigation.GotoRelatedItem
+import com.intellij.openapi.diagnostic.Logger
+import com.intellij.openapi.editor.markup.GutterIconRenderer
+import com.intellij.openapi.vfs.LocalFileSystem
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiFile
+import com.intellij.psi.PsiManager
+import com.intellij.psi.util.findDescendantOfType
+import icons.JavaScriptPsiIcons
+import org.rust.lang.core.psi.RsEnumItem
+import org.rust.lang.core.psi.RsFunction
+import org.rust.lang.core.psi.RsImplItem
+import org.rust.lang.core.psi.RsStructItem
+import org.rust.lang.core.psi.ext.RsOuterAttributeOwner
+import org.rust.lang.core.psi.ext.RsVisibilityOwner
+import org.rust.lang.core.psi.ext.containingCargoPackage
+import org.rust.lang.core.psi.ext.findOuterAttr
+import org.rust.lang.core.psi.impl.RsBaseTypeImpl
+import java.nio.file.InvalidPathException
+import java.nio.file.Paths
+
+class RsWasmBindgenLineMarkerProvider : RelatedItemLineMarkerProvider() {
+    override fun getLineMarkerInfo(element: PsiElement): RelatedItemLineMarkerInfo<*>? {
+        val element = element as? RsOuterAttributeOwner ?: return null
+        if (element !is RsFunction && element !is RsEnumItem && element !is RsStructItem && element !is RsImplItem) {
+            return null
+        }
+
+        // Check the package has wasm-bindgen as dependency
+        val cargoPackage = element.containingCargoPackage ?: return null
+        if (cargoPackage.dependencies.none { it.pkg.name == "wasm-bindgen" }) {
+            return null
+        }
+
+        // Only public elements are exposed in bindings
+        if (element is RsVisibilityOwner && element !is RsImplItem && !element.isPublic) {
+            return null
+        }
+
+        val attr = element.findOuterAttr("wasm_bindgen") ?: return null
+
+        val basePath = cargoPackage.contentRoot?.path ?: return null
+        val expectedName = cargoPackage.normName
+
+        // Expecting to find related generated typescript declarations in pkg/ folder of current package
+        val expectedPath = try {
+            Paths.get(basePath, "pkg/$expectedName.d.ts").toString()
+        } catch (e: InvalidPathException) {
+            LOG.error(e)
+            return null
+        }
+        val tsFile = LocalFileSystem.getInstance().findFileByPath(expectedPath) ?: return null
+        val tsPsiFile = PsiManager.getInstance(element.project).findFile(tsFile) ?: return null
+
+        // Trying to find the correlating element with the same name
+        val destination = when (element) {
+            // If it is impl, then resolving to the related struct and using its name
+            is RsImplItem -> {
+                val reference = (element.typeReference as? RsBaseTypeImpl) ?: return null
+                val struct = (reference.path?.reference?.resolve() as? RsStructItem) ?: return null
+                findRelatedTsElement(struct, tsPsiFile)
+            }
+            else -> findRelatedTsElement(element, tsPsiFile)
+        } ?: return null
+
+        return RelatedItemLineMarkerInfo(
+            attr,
+            attr.textRange,
+            JavaScriptPsiIcons.FileTypes.TypeScriptFile,
+            { "Related generated declaration" },
+            DefaultGutterIconNavigationHandler(listOf(destination), "Generated declarations"),
+            GutterIconRenderer.Alignment.RIGHT,
+            { listOf(GotoRelatedItem(destination)) }
+        )
+    }
+
+    private fun findRelatedTsElement(element: RsOuterAttributeOwner, tsPsiFile: PsiFile): JSElement? =
+        when (element) {
+            is RsFunction -> tsPsiFile.findDescendantOfType<TypeScriptFunction> { it.name == element.name }
+            is RsEnumItem -> tsPsiFile.findDescendantOfType<TypeScriptEnum> { it.name == element.name }
+            is RsStructItem -> tsPsiFile.findDescendantOfType<TypeScriptClass> { it.name == element.name }
+            else -> null
+        }
+
+    companion object {
+        private val LOG: Logger = Logger.getInstance(RsWasmBindgenLineMarkerProvider::class.java)
+    }
+}

js/src/main/resources/META-INF/js-only.xml

@@ -1,4 +1,5 @@
 <idea-plugin>
     <extensions defaultExtensionNs="com.intellij">
+        <codeInsight.lineMarkerProvider language="Rust" implementationClass="org.rust.js.RsWasmBindgenLineMarkerProvider"/>
     </extensions>
 </idea-plugin>