New command to resolve main class - used for run/debug code lenses in editors

server/src/main/kotlin/org/javacs/kt/CompilerClassPath.kt

@@ -15,7 +15,8 @@ import java.nio.file.Path
  * and the compiler. Note that Kotlin sources are stored in SourcePath.
  */
 class CompilerClassPath(private val config: CompilerConfiguration) : Closeable {
-    private val workspaceRoots = mutableSetOf<Path>()
+    val workspaceRoots = mutableSetOf<Path>()
+
     private val javaSourcePath = mutableSetOf<Path>()
     private val buildScriptClassPath = mutableSetOf<Path>()
     val classPath = mutableSetOf<ClassPathEntry>()

server/src/main/kotlin/org/javacs/kt/KotlinLanguageServer.kt

@@ -30,7 +30,7 @@ class KotlinLanguageServer : LanguageServer, LanguageClientAware, Closeable {
 
     private val textDocuments = KotlinTextDocumentService(sourceFiles, sourcePath, config, tempDirectory, uriContentProvider, classPath)
     private val workspaces = KotlinWorkspaceService(sourceFiles, sourcePath, classPath, textDocuments, config)
-    private val protocolExtensions = KotlinProtocolExtensionService(uriContentProvider, classPath)
+    private val protocolExtensions = KotlinProtocolExtensionService(uriContentProvider, classPath, sourcePath)
 
     private lateinit var client: LanguageClient
 

server/src/main/kotlin/org/javacs/kt/KotlinProtocolExtensionService.kt

@@ -3,11 +3,14 @@ package org.javacs.kt
 import org.eclipse.lsp4j.*
 import org.javacs.kt.util.AsyncExecutor
 import org.javacs.kt.util.parseURI
+import org.javacs.kt.resolve.resolveMain
 import java.util.concurrent.CompletableFuture
+import java.nio.file.Paths
 
 class KotlinProtocolExtensionService(
     private val uriContentProvider: URIContentProvider,
-    private val cp: CompilerClassPath
+    private val cp: CompilerClassPath,
+    private val sp: SourcePath
 ) : KotlinProtocolExtensions {
     private val async = AsyncExecutor()
 
@@ -18,4 +21,22 @@ class KotlinProtocolExtensionService(
     override fun buildOutputLocation(): CompletableFuture<String?> = async.compute {
         cp.outputDirectory.absolutePath
     }
+
+    override fun mainClass(textDocument: TextDocumentIdentifier): CompletableFuture<Map<String, Any?>> = async.compute {
+        val fileUri = parseURI(textDocument.uri)
+        val filePath = Paths.get(fileUri)
+
+        // we find the longest one in case both the root and submodule are included
+        val workspacePath = cp.workspaceRoots.filter {
+            filePath.startsWith(it)
+        }.map {
+            it.toString()
+        }.maxByOrNull(String::length) ?: ""
+
+        val compiledFile = sp.currentVersion(fileUri)
+
+        resolveMain(compiledFile) + mapOf(
+            "projectRoot" to workspacePath
+        )
+    }
 }

server/src/main/kotlin/org/javacs/kt/KotlinProtocolExtensions.kt

@@ -12,4 +12,7 @@ interface KotlinProtocolExtensions {
 
     @JsonRequest
     fun buildOutputLocation(): CompletableFuture<String?>
+
+    @JsonRequest
+    fun mainClass(textDocument: TextDocumentIdentifier): CompletableFuture<Map<String, Any?>>
 }

server/src/main/kotlin/org/javacs/kt/KotlinWorkspaceService.kt

@@ -13,6 +13,7 @@ import org.javacs.kt.KotlinTextDocumentService
 import org.javacs.kt.position.extractRange
 import org.javacs.kt.util.filePath
 import org.javacs.kt.util.parseURI
+import org.javacs.kt.resolve.resolveMain
 import java.net.URI
 import java.nio.file.Paths
 import java.util.concurrent.CompletableFuture
@@ -29,7 +30,7 @@ class KotlinWorkspaceService(
 ) : WorkspaceService, LanguageClientAware {
     private val gson = Gson()
     private var languageClient: LanguageClient? = null
-
+ 
     override fun connect(client: LanguageClient): Unit {
         languageClient = client
     }

server/src/main/kotlin/org/javacs/kt/command/Commands.kt

@@ -1,6 +1,7 @@
 package org.javacs.kt.command
 
 const val JAVA_TO_KOTLIN_COMMAND = "convertJavaToKotlin"
+
 val ALL_COMMANDS = listOf(
-	JAVA_TO_KOTLIN_COMMAND
+    JAVA_TO_KOTLIN_COMMAND,
 )

server/src/main/kotlin/org/javacs/kt/resolve/ResolveMain.kt

@@ -0,0 +1,62 @@
+package org.javacs.kt.resolve
+
+import org.jetbrains.kotlin.fileClasses.JvmFileClassUtil
+import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.KtNamedFunction
+import org.jetbrains.kotlin.psi.KtClass
+import org.jetbrains.kotlin.psi.KtObjectDeclaration
+import org.javacs.kt.CompiledFile
+import org.javacs.kt.position.range
+import org.javacs.kt.util.partitionAroundLast
+import com.intellij.openapi.util.TextRange
+
+
+fun resolveMain(file: CompiledFile): Map<String,Any> {
+    val parsedFile = file.parse.copy() as KtFile
+
+    val mainFunction = findTopLevelMainFunction(parsedFile)
+    if(null != mainFunction) {
+        // the KtFiles name is weird. Full path. This causes the class to have full path in name as well. Correcting to top level only
+        parsedFile.name = parsedFile.name.partitionAroundLast("/").second.substring(1)
+
+        return mapOf("mainClass" to JvmFileClassUtil.getFileClassInfoNoResolve(parsedFile).facadeClassFqName.asString(),
+                     "range" to range(file.content, mainFunction.second))
+    }
+
+    val companionMain = findCompanionObjectMain(parsedFile)
+    if(null != companionMain) {
+        return mapOf(
+            "mainClass" to (companionMain.first ?: ""),
+            "range" to range(file.content, companionMain.second)
+        )
+    }
+
+    return emptyMap()
+}
+
+// only one main method allowed top level in a file (so invalid syntax files will not show any main methods)
+private fun findTopLevelMainFunction(file: KtFile): Pair<String?, TextRange>? = file.declarations.find {
+    it is KtNamedFunction && "main" == it.name
+}?.let {
+    Pair(it.name, it.textRangeInParent)
+}
+
+// finds a top level class that contains a companion object with a main function inside
+private fun findCompanionObjectMain(file: KtFile): Pair<String?, TextRange>? = file.declarations.flatMap { topLevelDeclaration ->
+    if(topLevelDeclaration is KtClass) {
+        topLevelDeclaration.companionObjects
+    } else {
+        emptyList<KtObjectDeclaration>()
+    }
+}.flatMap {    companionObject ->
+    companionObject.body?.children?.toList() ?: emptyList()
+}.mapNotNull {  companionObjectInternal ->
+    if(companionObjectInternal is KtNamedFunction && "main" == companionObjectInternal.name && companionObjectInternal.text.startsWith("@JvmStatic")) {
+        companionObjectInternal
+    } else {
+        null
+    }
+}.firstOrNull()?.let {
+    // a little ugly, but because of success of the above, we know that "it" has 4 layers of parent objects (child of companion object body, companion object body, companion object, outer class)
+    Pair((it.parent.parent.parent.parent as KtClass).fqName?.toString(), it.textRange)
+}

server/src/test/kotlin/org/javacs/kt/ResolveMainTest.kt

@@ -0,0 +1,76 @@
+package org.javacs.kt
+
+import com.google.gson.Gson
+import org.eclipse.lsp4j.ExecuteCommandParams
+import org.eclipse.lsp4j.Position
+import org.eclipse.lsp4j.Range
+import org.eclipse.lsp4j.TextDocumentIdentifier
+import org.junit.Test
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
+
+class NoMainResolve : SingleFileTestFixture("resolvemain", "NoMain.kt") {
+    @Test
+    fun `Should not find any main class info`() {
+        val root = testResourcesRoot().resolve(workspaceRoot)
+        val fileUri = root.resolve(file).toUri().toString()
+
+        val result = languageServer.getProtocolExtensionService().mainClass(TextDocumentIdentifier(fileUri)).get()
+
+        assertNotNull(result)
+        val mainInfo = result as Map<String, String>
+        assertNull(mainInfo["mainClass"])
+        assertEquals(root.toString(), mainInfo["projectRoot"])
+    }
+}
+
+
+class SimpleMainResolve : SingleFileTestFixture("resolvemain", "Simple.kt") {
+    @Test
+    fun `Should resolve correct main class of simple file`() {
+        val root = testResourcesRoot().resolve(workspaceRoot)
+        val fileUri = root.resolve(file).toUri().toString()
+
+        val result = languageServer.getProtocolExtensionService().mainClass(TextDocumentIdentifier(fileUri)).get()
+
+        assertNotNull(result)
+        val mainInfo = result as Map<String, Any>
+        assertEquals("test.SimpleKt", mainInfo["mainClass"])
+        assertEquals(Range(Position(2, 0), Position(4, 1)), mainInfo["range"])
+        assertEquals(root.toString(), mainInfo["projectRoot"])
+    }
+}
+
+
+class JvmNameAnnotationMainResolve : SingleFileTestFixture("resolvemain", "JvmNameAnnotation.kt") {
+    @Test
+    fun `Should resolve correct main class of file annotated with JvmName`() {
+        val root = testResourcesRoot().resolve(workspaceRoot)
+        val fileUri = root.resolve(file).toUri().toString()
+
+        val result = languageServer.getProtocolExtensionService().mainClass(TextDocumentIdentifier(fileUri)).get()
+
+        assertNotNull(result)
+        val mainInfo = result as Map<String, Any>
+        assertEquals("com.mypackage.name.Potato", mainInfo["mainClass"])
+        assertEquals(Range(Position(5, 0), Position(7, 1)), mainInfo["range"])
+        assertEquals(root.toString(), mainInfo["projectRoot"])
+    }
+}
+
+class CompanionObjectMainResolve : SingleFileTestFixture("resolvemain", "CompanionObject.kt") {
+    @Test
+    fun `Should resolve correct main class of main function inside companion object`() {
+        val root = testResourcesRoot().resolve(workspaceRoot)
+        val fileUri = root.resolve(file).toUri().toString()
+
+        val result = languageServer.getProtocolExtensionService().mainClass(TextDocumentIdentifier(fileUri)).get()
+
+        assertNotNull(result)
+        val mainInfo = result as Map<String, Any>
+        assertEquals("test.my.companion.SweetPotato", mainInfo["mainClass"])
+        assertEquals(Range(Position(8, 8), Position(11, 9)), mainInfo["range"])
+        assertEquals(root.toString(), mainInfo["projectRoot"])
+    }
+}

server/src/test/resources/resolvemain/CompanionObject.kt

@@ -0,0 +1,14 @@
+package test.my.companion
+
+val SOME_GLOBAL_CONSTANT = 42
+
+fun multiplyByOne(num: Int) = num*1
+
+class SweetPotato {
+    companion object {
+        @JvmStatic
+        fun main() {
+            println("42 multiplied by 1: ${multiplyByOne(42)}")
+        }
+    }
+}

server/src/test/resources/resolvemain/JvmNameAnnotation.kt

@@ -0,0 +1,8 @@
+@JvmName("Potato")
+package com.mypackage.name
+
+val MY_CONSTANT = 1
+
+fun main(args: Array<String>) {
+
+}

server/src/test/resources/resolvemain/NoMain.kt

@@ -0,0 +1,3 @@
+package no.main.found.hopefully
+
+fun multiplyByOne(num: Int) = num*1

server/src/test/resources/resolvemain/Simple.kt

@@ -0,0 +1,5 @@
+package test
+
+fun main() {
+	println("Hello!")
+}