Change the design to track addRoot and removeRoot

src/harness/unittests/tsserverProjectSystem.ts

@@ -1620,7 +1620,7 @@ namespace ts.projectSystem {
             const configureHostRequest = makeSessionRequest<protocol.ConfigureRequestArguments>(CommandNames.Configure, { extraFileExtensions });
             session.executeCommand(configureHostRequest).response;
 
-             // HTML file still not included in the project as it is closed
+            // HTML file still not included in the project as it is closed
             checkNumberOfProjects(projectService, { configuredProjects: 1 });
             checkProjectActualFiles(projectService.configuredProjects[0], [file1.path]);
 
@@ -3053,7 +3053,7 @@ namespace ts.projectSystem {
     });
 
     describe("maxNodeModuleJsDepth for inferred projects", () => {
-        it("should be set by default", () => {
+        it("should be set to 2 if the project has js root files", () => {
             const file1: FileOrFolder = {
                 path: "/a/b/file1.js",
                 content: `var t = require("test"); t.`
@@ -3077,6 +3077,33 @@ namespace ts.projectSystem {
             options = project.getCompilerOptions();
             assert.isTrue(options.maxNodeModuleJsDepth === 2);
         });
+
+        it("should return to normal state when all js root files are removed from project", () => {
+            const file1 = {
+                path: "/a/file1.ts",
+                content: "let x =1;"
+            };
+            const file2 = {
+                path: "/a/file2.js",
+                content: "let x =1;"
+            };
+
+            const host = createServerHost([file1, file2, libFile]);
+            const projectService = createProjectService(host, { useSingleInferredProject: true });
+
+            projectService.openClientFile(file1.path);
+            checkNumberOfInferredProjects(projectService, 1);
+            let project = projectService.inferredProjects[0];
+            assert.isUndefined(project.getCompilerOptions().maxNodeModuleJsDepth);
+
+            projectService.openClientFile(file2.path);
+            project = projectService.inferredProjects[0];
+            assert.isTrue(project.getCompilerOptions().maxNodeModuleJsDepth === 2);
+
+            projectService.closeClientFile(file2.path);
+            project = projectService.inferredProjects[0];
+            assert.isUndefined(project.getCompilerOptions().maxNodeModuleJsDepth);
+        });
     });
 
 }