tsserver should use newline provided by the host (#13185)

Author: vladima

src/harness/unittests/compileOnSave.ts

@@ -467,6 +467,36 @@ namespace ts.projectSystem {
     });
 
     describe("EmitFile test", () => {
+        it("should respect line endings", () => {
+            test("\n");
+            test("\r\n");
+
+            function test(newLine: string) {
+                const lines = ["var x = 1;", "var y = 2;"];
+                const path = "/a/app";
+                const f = {
+                    path: path + ".ts",
+                    content: lines.join(newLine)
+                };
+                const host = createServerHost([f], { newLine });
+                const session = createSession(host);
+                session.executeCommand(<server.protocol.OpenRequest>{
+                    seq: 1,
+                    type: "request",
+                    command: "open",
+                    arguments: { file: f.path }
+                });
+                session.executeCommand(<server.protocol.CompileOnSaveEmitFileRequest>{
+                    seq: 2,
+                    type: "request",
+                    command: "compileOnSaveEmitFile",
+                    arguments: { file: f.path }
+                });
+                const emitOutput = host.readFile(path + ".js");
+                assert.equal(emitOutput, f.content + newLine, "content of emit output should be identical with the input + newline");
+            }
+        })
+
         it("should emit specified file", () => {
             const file1 = {
                 path: "/a/b/f1.ts",
@@ -480,7 +510,7 @@ namespace ts.projectSystem {
                 path: "/a/b/tsconfig.json",
                 content: `{}`
             };
-            const host = createServerHost([file1, file2, configFile, libFile]);
+            const host = createServerHost([file1, file2, configFile, libFile], { newLine: "\r\n" });
             const typingsInstaller = createTestTypingsInstaller(host);
             const session = new server.Session(host, nullCancellationToken, /*useSingleInferredProject*/ false, typingsInstaller, Utils.byteLength, process.hrtime, nullLogger, /*canUseEvents*/ false);
 

src/harness/unittests/tsserverProjectSystem.ts

@@ -141,6 +141,7 @@ namespace ts.projectSystem {
         useCaseSensitiveFileNames?: boolean;
         executingFilePath?: string;
         currentDirectory?: string;
+        newLine?: string;
     }
 
     export function createServerHost(fileOrFolderList: FileOrFolder[], params?: TestServerHostCreationParameters): TestServerHost {
@@ -151,7 +152,8 @@ namespace ts.projectSystem {
             params.useCaseSensitiveFileNames !== undefined ? params.useCaseSensitiveFileNames : false,
             params.executingFilePath || getExecutingFilePathFromLibFile(),
             params.currentDirectory || "/",
-            fileOrFolderList);
+            fileOrFolderList,
+            params.newLine);
         return host;
     }
 
@@ -329,7 +331,6 @@ namespace ts.projectSystem {
 
     export class TestServerHost implements server.ServerHost {
         args: string[] = [];
-        newLine: "\n";
 
         private fs: ts.FileMap<FSEntry>;
         private getCanonicalFileName: (s: string) => string;
@@ -342,7 +343,7 @@ namespace ts.projectSystem {
 
         private filesOrFolders: FileOrFolder[];
 
-        constructor(public useCaseSensitiveFileNames: boolean, private executingFilePath: string, private currentDirectory: string, fileOrFolderList: FileOrFolder[]) {
+        constructor(public useCaseSensitiveFileNames: boolean, private executingFilePath: string, private currentDirectory: string, fileOrFolderList: FileOrFolder[], public readonly newLine = "\n") {
             this.getCanonicalFileName = createGetCanonicalFileName(useCaseSensitiveFileNames);
             this.toPath = s => toPath(s, currentDirectory, this.getCanonicalFileName);
 

src/server/lsHost.ts

@@ -135,6 +135,10 @@ namespace ts.server {
             }
         }
 
+        getNewLine() {
+            return this.host.newLine;
+        }
+
         getProjectVersion() {
             return this.project.getProjectVersion();
         }