GH-2595: The d.ts export should append .js file extensions in import statements (#2598)

* d.ts exports emit type imports including file extension

* respect existing file extension

* add test

* fix fileExtension()

* fix xt framework

* respect bare imports

* add test

Author: mmews-n4

plugins/org.eclipse.n4js.transpiler.dts/src/org/eclipse/n4js/transpiler/dts/print/PrettyPrinterDts.java

@@ -43,6 +43,7 @@
 import org.eclipse.n4js.n4JS.ImportDeclaration;
 import org.eclipse.n4js.n4JS.ImportSpecifier;
 import org.eclipse.n4js.n4JS.LiteralOrComputedPropertyName;
+import org.eclipse.n4js.n4JS.ModuleSpecifierForm;
 import org.eclipse.n4js.n4JS.N4ClassDeclaration;
 import org.eclipse.n4js.n4JS.N4ClassifierDeclaration;
 import org.eclipse.n4js.n4JS.N4EnumDeclaration;
@@ -89,6 +90,7 @@
 import org.eclipse.n4js.typesystem.utils.RuleEnvironmentExtensions;
 import org.eclipse.n4js.utils.N4JSLanguageUtils;
 import org.eclipse.n4js.utils.N4JSLanguageUtils.EnumKind;
+import org.eclipse.n4js.utils.URIUtils;
 import org.eclipse.n4js.utils.parser.conversion.ValueConverterUtils;
 import org.eclipse.xtext.EcoreUtil2;
 
@@ -214,8 +216,19 @@ public Boolean caseImportDeclaration(ImportDeclaration original) {
 				? original.getModuleSpecifierAsText().replace("%3A", ":") // see ModuleSpecifierValueConverter
 				: original.getModule().getQualifiedName();
 
+		if (original.getModuleSpecifierForm() != ModuleSpecifierForm.PROJECT
+				&& Strings.isNullOrEmpty(URIUtils.fileExtension(URIUtils.toFileUri(moduleSpecifier)))) {
+
+			String extension = original.isBare() ? N4JSGlobals.JS_FILE_EXTENSION : N4JSGlobals.DTS_FILE_EXTENSION;
+			moduleSpecifier += "." + extension;
+		}
+
 		processAnnotations(original.getAnnotations());
 		write("import ");
+		if (!original.isBare()) {
+			write("type ");
+		}
+
 		// 1) import specifiers
 		List<ImportSpecifier> importSpecifiers = new ArrayList<>(original.getImportSpecifiers());
 		if (!importSpecifiers.isEmpty() && importSpecifiers.get(0) instanceof DefaultImportSpecifier) {

plugins/org.eclipse.n4js.utils/src/org/eclipse/n4js/utils/URIUtils.java

@@ -93,12 +93,17 @@ static private int fileExtensionIndex(URI uri) {
 		if (firstIdx < 0) {
 			return -1;
 		}
+		boolean foundDot = false;
 		for (int idx = firstIdx; idx > 0; idx--) {
 			if (lastSegment.charAt(idx) == '.') {
+				foundDot = true;
 				firstIdx = idx + 1;
 				break;
 			}
 		}
+		if (!foundDot) {
+			return -1;
+		}
 		String ext1 = lastSegment.substring(firstIdx);
 		if (extensionPrefixes.containsKey(ext1)) {
 			int scndIdx = firstIdx - 2;

testhelpers/org.eclipse.n4js.ide.tests.helper/src/org/eclipse/n4js/ide/tests/helper/server/xt/XtIdeTest.java

@@ -773,10 +773,12 @@ public void generated_dts(XtMethodData data) throws IOException {
 
 			for (Project project : allProjectsWithGenerateDts) {
 				File workingDir = getProjectRoot(project.getName());
+				Path wdSrcDir = workingDir.toPath().resolve("src-gen");
+				wdSrcDir.toFile().mkdirs(); // might not exist e.g. if is a definition project
 
 				// copy n4jsglobals.d.ts to output dir to make d.ts globals available
 				Path n4jsGlobalsDTS = N4jsLibsAccess.getN4JSGlobalsDTS();
-				Files.copy(n4jsGlobalsDTS, workingDir.toPath().resolve("src-gen/n4jsglobals.d.ts"));
+				Files.copy(n4jsGlobalsDTS, wdSrcDir.resolve("n4jsglobals.d.ts"));
 
 				ProcessResult result;
 				try {

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/cutOffReferences/ReferenceToNonDtsProject.n4js.xt

@@ -51,7 +51,7 @@ export public class Cls1 extends ClassWithDts {}
 export public class Cls2 extends ClassWithoutDts {}
 
 /* XPECT generated_dts ---
-import {ClassWithDts} from 'ProjectOtherWithDts/src-gen/OtherWithDts'
+import type {ClassWithDts} from 'ProjectOtherWithDts/src-gen/OtherWithDts.d.ts'
 
 export let v1: ClassWithDts;
 export let v2: any;

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/BareImport.n4js.xt

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2021 NumberFour AG.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   NumberFour AG - Initial API and implementation
+ */
+
+/* XPECT_SETUP org.eclipse.n4js.spec.tests.SpecXtTest
+
+	Workspace {
+		Project "TestProject" {
+			Folder "src" {
+				ThisFile {}
+				File "BareImportMe.js" { }
+			}
+		}
+	}
+	
+	File "BareImportMe.js" {
+		export public class CP {}
+	}
+
+	GENERATE_DTS
+
+END_SETUP */
+
+
+
+import "BareImportMe";
+
+
+
+/* XPECT generated_dts ---
+import './BareImportMe.js'
+
+--- */

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/DefaultAsImport.n4js.xt

@@ -34,7 +34,7 @@ export public class Dummy extends MyClass {} // ensures that the import is not r
 
 
 /* XPECT generated_dts ---
-import {default as MyClass} from './Other'
+import type {default as MyClass} from './Other.d.ts'
 
 export class Dummy extends MyClass {}
 --- */

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/ImportForLiteralType1.n4js.xt

@@ -38,10 +38,10 @@ export public const redStringBased = ColorStringBased.RED;
 
 
 /* XPECT generated_dts ---
-import {Color} from './Other'
-import {ColorWithLiteralValues} from './Other'
-import {ColorNumberBased} from './Other'
-import {ColorStringBased} from './Other'
+import type {Color} from './Other.d.ts'
+import type {ColorWithLiteralValues} from './Other.d.ts'
+import type {ColorNumberBased} from './Other.d.ts'
+import type {ColorStringBased} from './Other.d.ts'
 
 export const red: Color;
 export const redWithLiteralValues: ColorWithLiteralValues;

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/ImportForLiteralType2.n4js.xt

@@ -38,10 +38,10 @@ export public const redStringBased = getRedStringBased();
 
 
 /* XPECT generated_dts ---
-import {ColorStringBased} from './Other'
-import {ColorNumberBased} from './Other'
-import {ColorWithLiteralValues} from './Other'
-import {Color} from './Other'
+import type {ColorStringBased} from './Other.d.ts'
+import type {ColorNumberBased} from './Other.d.ts'
+import type {ColorWithLiteralValues} from './Other.d.ts'
+import type {Color} from './Other.d.ts'
 
 export const red: Color;
 export const redWithLiteralValues: ColorWithLiteralValues;

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/ImportMustBeAdded1.n4js.xt

@@ -32,7 +32,7 @@ export const C = F();
 
 
 /* XPECT generated_dts ---
-import {Cls} from './Other'
+import type {Cls} from './Other.d.ts'
 
 export const C: Cls;
 --- */

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/ImportMustBeAdded2_withAlias.n4js.xt

@@ -37,7 +37,7 @@ class Cls {
 
 
 /* XPECT generated_dts ---
-import {Cls as Cls2} from './Other'
+import type {Cls as Cls2} from './Other.d.ts'
 
 export const C: Cls2;
 declare class Cls {}

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/ImportMustBeAdded3_forIndirectlyExportedElem.n4js.xt

@@ -43,7 +43,7 @@ export const C = F();
 
 
 /* XPECT generated_dts ---
-import {ClsExportedName} from './Other'
+import type {ClsExportedName} from './Other.d.ts'
 
 export const C: ClsExportedName;
 --- */

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/ImportWithExtension.n4js.xt

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2021 NumberFour AG.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   NumberFour AG - Initial API and implementation
+ */
+
+/* XPECT_SETUP org.eclipse.n4js.spec.tests.SpecXtTest
+
+	Workspace {
+		Project "TestProject" {
+			Folder "src" {
+				ThisFile {}
+			}
+			DEPENDS_ON "ImportMe"
+		}
+		Project "ImportMe" {
+			Folder "src" {
+				File "index.n4js" { }
+			}
+			File "package.json" {}
+		}
+	}
+	
+	File "index.n4js" {
+		export public class CP {}
+	}
+	
+	File "package.json" {
+		{
+			"name": "ImportMe",
+			"version": "1.0.0",
+			"type": "module",
+			"types": "src-gen/index.d.ts",
+			"scripts": {},
+			"n4js": {
+				"vendorId": "VENDOR",
+				"vendorName": "VENDOR_NAME",
+				"projectType": "library",
+				"output": "src-gen",
+				"generator": { "d.ts": true },
+				"sources": {
+					"source": ["./src"]
+				}
+			},
+			"dependencies": {
+				"n4js-runtime": ""
+			}
+		}
+	}
+
+	GENERATE_DTS
+
+END_SETUP */
+
+
+import * as TS from "ImportMe";
+
+export public class CPX extends TS.CP {}
+
+
+/* XPECT generated_dts ---
+import type * as TS from 'ImportMe'
+
+export class CPX extends TS.CP {}
+--- */

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/ModuleSpecifiers.n4js.xt

@@ -43,8 +43,8 @@ export let clsOtherLocal: ClsOtherLocal;
 
 
 /* XPECT generated_dts ---
-import {ClsOther as ClsOtherRemote} from 'ProjectOther/src-gen/RemoteOther'
-import {ClsOther as ClsOtherLocal} from './LocalOther'
+import type {ClsOther as ClsOtherRemote} from 'ProjectOther/src-gen/RemoteOther.d.ts'
+import type {ClsOther as ClsOtherLocal} from './LocalOther.d.ts'
 
 export let clsOtherRemote: ClsOtherRemote;
 export let clsOtherLocal: ClsOtherLocal;

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/NamespaceAccess.n4js.xt

@@ -36,7 +36,7 @@ export public class Cls extends NS.SomeClass {}
 
 
 /* XPECT generated_dts ---
-import * as NS from './Other'
+import type * as NS from './Other.d.ts'
 
 export let x: NS.SomeClass;
 export function foo(p: NS.SomeClass): NS.SomeClass;

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/imports/UseExistingNamespaceImport.n4js.xt

@@ -30,7 +30,7 @@ export public let x = NS.foo();
 
 
 /* XPECT generated_dts ---
-import * as NS from './Other'
+import type * as NS from './Other.d.ts'
 
 export let x: NS.ClsOther;
 --- */

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/inferredTypes/InferredTypes2.n4js.xt

@@ -58,7 +58,7 @@ export class ClassWithFields {
 
 
 /* XPECT generated_dts ---
-import {ClassDirectExported} from 'ProjectOtherDirect/src-gen/OtherDirect'
+import type {ClassDirectExported} from 'ProjectOtherDirect/src-gen/OtherDirect.d.ts'
 
 export let v1: ClassDirectExported;
 export let v2: any;

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/inferredTypes/InferredTypesImportUsedInStatement.n4js.xt

@@ -37,7 +37,7 @@ export class ClassWithFields {
 
 
 /* XPECT generated_dts ---
-import {ClassOther} from './Other'
+import type {ClassOther} from './Other.d.ts'
 
 export let v: ClassOther;
 export class ClassWithFields {

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/inferredTypes/ReplaceWildcard.n4js.xt

@@ -29,8 +29,8 @@ import {C} from "Other";
 const c: C<?> = null
 
 /* XPECT generated_dts ---
-import {D} from './Other'
-import {C} from './Other'
+import type {D} from './Other.d.ts'
+import type {C} from './Other.d.ts'
 
 declare const c: C<D>;
 --- */

tests/org.eclipse.n4js.spec.tests/xt-tests/dts-export/inferredTypes/UpperBounds.n4js.xt

@@ -43,9 +43,9 @@ export class ClassWithFields {
 
 
 /* XPECT generated_dts ---
-import {ClassExported} from 'ProjectOther/src-gen/Other'
-import {GenClassOfClassExported} from 'ProjectOther/src-gen/Other'
-import {GenClassOfClassNotExported} from 'ProjectOther/src-gen/Other'
+import type {ClassExported} from 'ProjectOther/src-gen/Other.d.ts'
+import type {GenClassOfClassExported} from 'ProjectOther/src-gen/Other.d.ts'
+import type {GenClassOfClassNotExported} from 'ProjectOther/src-gen/Other.d.ts'
 
 export let v1: GenClassOfClassExported<ClassExported>;
 export let v2: GenClassOfClassNotExported<any>;