Cherrypicking PR 5593

src/harness/fourslash.ts

@@ -373,17 +373,17 @@ namespace FourSlash {
         }
 
         // Opens a file given its 0-based index or fileName
-        public openFile(index: number): void;
-        public openFile(name: string): void;
-        public openFile(indexOrName: any) {
-            let fileToOpen: FourSlashFile = this.findFile(indexOrName);
+        public openFile(index: number, content?: string): void;
+        public openFile(name: string, content?: string): void;
+        public openFile(indexOrName: any, content?: string) {
+            const fileToOpen: FourSlashFile = this.findFile(indexOrName);
             fileToOpen.fileName = ts.normalizeSlashes(fileToOpen.fileName);
             this.activeFile = fileToOpen;
-            let fileName = fileToOpen.fileName.replace(Harness.IO.directoryName(fileToOpen.fileName), "").substr(1);
+            const fileName = fileToOpen.fileName.replace(Harness.IO.directoryName(fileToOpen.fileName), "").substr(1);
             this.scenarioActions.push(`<OpenFile FileName="" SrcFileId="${fileName}" FileId="${fileName}" />`);
 
             // Let the host know that this file is now open
-            this.languageServiceAdapterHost.openFile(fileToOpen.fileName);
+            this.languageServiceAdapterHost.openFile(fileToOpen.fileName, content);
         }
 
         public verifyErrorExistsBetweenMarkers(startMarkerName: string, endMarkerName: string, negative: boolean) {

src/harness/harnessLanguageService.ts

@@ -153,7 +153,7 @@ namespace Harness.LanguageService {
             throw new Error("No script with name '" + fileName + "'");
         }
 
-        public openFile(fileName: string): void {
+        public openFile(fileName: string, content?: string): void {
         }
 
         /**
@@ -493,9 +493,9 @@ namespace Harness.LanguageService {
             this.client = client;
         }
 
-        openFile(fileName: string): void {
-            super.openFile(fileName);
-            this.client.openFile(fileName);
+        openFile(fileName: string, content?: string): void {
+            super.openFile(fileName, content);
+            this.client.openFile(fileName, content);
         }
 
         editScript(fileName: string, start: number, end: number, newText: string) {

src/server/client.ts

@@ -120,8 +120,8 @@ namespace ts.server {
             return response;
         }
 
-        openFile(fileName: string): void {
-            var args: protocol.FileRequestArgs = { file: fileName };
+        openFile(fileName: string, content?: string): void {
+            var args: protocol.OpenRequestArgs = { file: fileName, fileContent: content };
             this.processRequest(CommandNames.Open, args);
         }
 

src/server/editorServices.ts

@@ -992,14 +992,15 @@ namespace ts.server {
 
         /**
          * @param filename is absolute pathname
+         * @param fileContent is a known version of the file content that is more up to date than the one on disk
          */
-        openFile(fileName: string, openedByClient: boolean) {
+        openFile(fileName: string, openedByClient: boolean, fileContent?: string) {
             fileName = ts.normalizePath(fileName);
-            var info = ts.lookUp(this.filenameToScriptInfo, fileName);
+            let info = ts.lookUp(this.filenameToScriptInfo, fileName);
             if (!info) {
-                var content: string;
+                let content: string;
                 if (this.host.fileExists(fileName)) {
-                    content = this.host.readFile(fileName);
+                    content = fileContent || this.host.readFile(fileName);
                 }
                 if (!content) {
                     if (openedByClient) {
@@ -1017,6 +1018,9 @@ namespace ts.server {
                 }
             }
             if (info) {
+                if (fileContent) {
+                    info.svc.reload(fileContent);
+                }
                 if (openedByClient) {
                     info.isOpen = true;
                 }
@@ -1047,10 +1051,11 @@ namespace ts.server {
         /**
          * Open file whose contents is managed by the client
          * @param filename is absolute pathname
+         * @param fileContent is a known version of the file content that is more up to date than the one on disk
          */
-        openClientFile(fileName: string) {
+        openClientFile(fileName: string, fileContent?: string) {
             this.openOrUpdateConfiguredProjectForFile(fileName);
-            var info = this.openFile(fileName, true);
+            const info = this.openFile(fileName, true, fileContent);
             this.addOpenFile(info);
             this.printProjects();
             return info;

src/server/protocol.d.ts

@@ -513,6 +513,11 @@ declare namespace ts.server.protocol {
       *  Information found in an "open" request.
       */
     export interface OpenRequestArgs extends FileRequestArgs {
+        /**
+         * Used when a version of the file content is known to be more up to date than the one on disk. 
+         * Then the known content will be used upon opening instead of the disk copy   
+         */
+        fileContent?: string;
     }
 
     /**

src/server/session.ts

@@ -4,7 +4,7 @@
 /// <reference path="editorServices.ts" />
 
 namespace ts.server {
-    var spaceCache:string[] = [];
+    const spaceCache: string[] = [];
 
     interface StackTraceError extends Error {
         stack?: string;
@@ -531,9 +531,13 @@ namespace ts.server {
             };
         }
 
-        private openClientFile(fileName: string) {
-            var file = ts.normalizePath(fileName);
-            this.projectService.openClientFile(file);
+        /**
+         * @param fileName is the name of the file to be opened
+         * @param fileContent is a version of the file content that is known to be more up to date than the one on disk
+         */
+        private openClientFile(fileName: string, fileContent?: string) {
+            const file = ts.normalizePath(fileName);
+            this.projectService.openClientFile(file, fileContent);
         }
 
         private getQuickInfo(line: number, offset: number, fileName: string): protocol.QuickInfoResponseBody {
@@ -966,7 +970,7 @@ namespace ts.server {
             },
             [CommandNames.Open]: (request: protocol.Request) => {
                 var openArgs = <protocol.OpenRequestArgs>request.arguments;
-                this.openClientFile(openArgs.file);
+                this.openClientFile(openArgs.file, openArgs.fileContent);
                 return {responseRequired: false}
             },
             [CommandNames.Quickinfo]: (request: protocol.Request) => {

tests/cases/fourslash/fourslash.ts

@@ -169,10 +169,10 @@ module FourSlashInterface {
         // Opens a file, given either its index as it
         // appears in the test source, or its filename
         // as specified in the test metadata
-        public file(index: number);
-        public file(name: string);
-        public file(indexOrName: any) {
-            FourSlash.currentTestState.openFile(indexOrName);
+        public file(index: number, content?: string);
+        public file(name: string, content?: string);
+        public file(indexOrName: any, content?: string) {
+            FourSlash.currentTestState.openFile(indexOrName, content);
         }
     }
 

tests/cases/fourslash/server/openFile.ts

@@ -0,0 +1,16 @@
+/// <reference path="../fourslash.ts"/>
+
+// @Filename: test1.ts
+////t.
+
+// @Filename: test.ts
+////var t = '10';
+
+// @Filename: tsconfig.json
+////{ "files": ["test.ts", "test1.ts"] }
+
+var overridingContent = "var t = 10; t.";
+goTo.file("test.ts", overridingContent);
+goTo.file("test1.ts");
+goTo.eof();
+verify.completionListContains("toExponential");