defer setting format options on file until it is explicitly requested

src/harness/unittests/tsserverProjectSystem.ts

@@ -1909,4 +1909,45 @@ namespace ts.projectSystem {
             checkProjectActualFiles(projectService.configuredProjects[0], [f1.path, barTypings.path]);
         });
     });
+
+    describe("format settings", () => {
+        it("can be set globally", () => {
+            const f1 = {
+                path: "/a/b/app.ts",
+                content: "let x;"
+            };
+            const host = createServerHost([f1]);
+            const projectService = createProjectService(host);
+            projectService.openClientFile(f1.path);
+
+            const defaultSettings = projectService.getFormatCodeOptions();
+
+            // set global settings
+            const newGlobalSettings1 = clone(defaultSettings);
+            newGlobalSettings1.placeOpenBraceOnNewLineForControlBlocks = !newGlobalSettings1.placeOpenBraceOnNewLineForControlBlocks;
+            projectService.setHostConfiguration({ formatOptions: newGlobalSettings1 });
+
+            // get format options for file - should be equal to new global settings
+            const s1 = projectService.getFormatCodeOptions(server.toNormalizedPath(f1.path));
+            assert.deepEqual(s1, newGlobalSettings1, "file settings should be the same with global settings");
+
+            // set per file format options
+            const newPerFileSettings = clone(defaultSettings);
+            newPerFileSettings.insertSpaceAfterCommaDelimiter = !newPerFileSettings.insertSpaceAfterCommaDelimiter;
+            projectService.setHostConfiguration({ formatOptions: newPerFileSettings, file: f1.path });
+
+            // get format options for file - should be equal to new per-file settings
+            const s2 = projectService.getFormatCodeOptions(server.toNormalizedPath(f1.path));
+            assert.deepEqual(s2, newPerFileSettings, "file settings should be the same with per-file settings");
+
+            // set new global settings - they should not affect ones that were set per-file
+            const newGlobalSettings2 = clone(defaultSettings);
+            newGlobalSettings2.insertSpaceAfterSemicolonInForStatements = !newGlobalSettings2.insertSpaceAfterSemicolonInForStatements;
+            projectService.setHostConfiguration({ formatOptions: newGlobalSettings2 });
+
+            // get format options for file - should be equal to new per-file settings
+            const s3 = projectService.getFormatCodeOptions(server.toNormalizedPath(f1.path));
+            assert.deepEqual(s3, newPerFileSettings, "file settings should still be the same with per-file settings");
+        });
+    });
 }

src/server/editorServices.ts

@@ -290,13 +290,14 @@ namespace ts.server {
         }
 
         getFormatCodeOptions(file?: NormalizedPath) {
+            let formatCodeSettings: FormatCodeSettings;
             if (file) {
                 const info = this.getScriptInfoForNormalizedPath(file);
                 if (info) {
-                    return info.formatCodeSettings;
+                    formatCodeSettings = info.getFormatCodeSettings();
                 }
             }
-            return this.hostConfiguration.formatCodeOptions;
+            return formatCodeSettings || this.hostConfiguration.formatCodeOptions;
         }
 
         private updateProjectGraphs(projects: Project[]) {
@@ -969,7 +970,6 @@ namespace ts.server {
                 }
                 if (content !== undefined) {
                     info = new ScriptInfo(this.host, fileName, content, scriptKind, openedByClient, hasMixedContent);
-                    info.setFormatOptions(toEditorSettings(this.getFormatCodeOptions()));
                     // do not watch files with mixed content - server doesn't know how to interpret it
                     this.filenameToScriptInfo.set(info.path, info);
                     if (!info.isOpen && !hasMixedContent) {

src/server/scriptInfo.ts

@@ -7,7 +7,7 @@ namespace ts.server {
          * All projects that include this file 
          */
         readonly containingProjects: Project[] = [];
-        readonly formatCodeSettings: ts.FormatCodeSettings;
+        private formatCodeSettings: ts.FormatCodeSettings;
         readonly path: Path;
 
         private fileWatcher: FileWatcher;
@@ -24,12 +24,15 @@ namespace ts.server {
 
             this.path = toPath(fileName, host.getCurrentDirectory(), createGetCanonicalFileName(host.useCaseSensitiveFileNames));
             this.svc = ScriptVersionCache.fromString(host, content);
-            this.formatCodeSettings = getDefaultFormatCodeSettings(this.host);
             this.scriptKind = scriptKind
                 ? scriptKind
                 : getScriptKindFromFileName(fileName);
         }
 
+        getFormatCodeSettings() {
+            return this.formatCodeSettings;
+        }
+
         attachToProject(project: Project): boolean {
             const isNew = !this.isAttached(project);
             if (isNew) {
@@ -90,6 +93,9 @@ namespace ts.server {
 
         setFormatOptions(formatSettings: protocol.FormatOptions): void {
             if (formatSettings) {
+                if (!this.formatCodeSettings) {
+                    this.formatCodeSettings = getDefaultFormatCodeSettings(this.host);
+                }
                 mergeMaps(this.formatCodeSettings, formatSettings);
             }
         }