Force new typings resolution only if there are more or less script infos in the project.

This helps in reducing number of forced typing installation requests
We anyways use changes in unresolved import array to determine if we need to enqueue new typing request
Hence there is no need to soley rely on hasChanges from updateGraph which just indicates that we didnt reused the program (that does not mean new files were added to the program or changes in unresolved imports)

Author: sheetalkamat

src/compiler/core.ts

@@ -2987,18 +2987,19 @@ namespace ts {
     }
 
     /** Remove the *first* occurrence of `item` from the array. */
-    export function unorderedRemoveItem<T>(array: T[], item: T): void {
+    export function unorderedRemoveItem<T>(array: T[], item: T) {
         unorderedRemoveFirstItemWhere(array, element => element === item);
     }
 
     /** Remove the *first* element satisfying `predicate`. */
-    function unorderedRemoveFirstItemWhere<T>(array: T[], predicate: (element: T) => boolean): void {
+    function unorderedRemoveFirstItemWhere<T>(array: T[], predicate: (element: T) => boolean) {
         for (let i = 0; i < array.length; i++) {
             if (predicate(array[i])) {
                 unorderedRemoveItemAt(array, i);
-                break;
+                return true;
             }
         }
+        return false;
     }
 
     export type GetCanonicalFileName = (fileName: string) => string;

src/server/project.ts

@@ -92,6 +92,8 @@ namespace ts.server {
         cachedUnresolvedImportsPerFile = createMap<ReadonlyArray<string>>();
         /*@internal*/
         lastCachedUnresolvedImportsList: SortedReadonlyArray<string>;
+        /*@internal*/
+        hasMoreOrLessScriptInfos = false;
 
         private lastFileExceededProgramSize: string | undefined;
 
@@ -777,6 +779,8 @@ namespace ts.server {
             this.resolutionCache.startRecordingFilesWithChangedResolutions();
 
             let hasChanges = this.updateGraphWorker();
+            const hasMoreOrLessScriptInfos = this.hasMoreOrLessScriptInfos;
+            this.hasMoreOrLessScriptInfos = false;
 
             const changedFiles: ReadonlyArray<Path> = this.resolutionCache.finishRecordingFilesWithChangedResolutions() || emptyArray;
 
@@ -803,7 +807,7 @@ namespace ts.server {
                     this.lastCachedUnresolvedImportsList = toDeduplicatedSortedArray(result);
                 }
 
-                const cachedTypings = this.projectService.typingsCache.getTypingsForProject(this, this.lastCachedUnresolvedImportsList, hasChanges);
+                const cachedTypings = this.projectService.typingsCache.getTypingsForProject(this, this.lastCachedUnresolvedImportsList, hasMoreOrLessScriptInfos);
                 if (!arrayIsEqualTo(this.typingFiles, cachedTypings)) {
                     this.typingFiles = cachedTypings;
                     this.markAsDirty();

src/server/scriptInfo.ts

@@ -304,6 +304,7 @@ namespace ts.server {
             const isNew = !this.isAttached(project);
             if (isNew) {
                 this.containingProjects.push(project);
+                project.hasMoreOrLessScriptInfos = true;
                 if (!project.getCompilerOptions().preserveSymlinks) {
                     this.ensureRealPath();
                 }
@@ -328,19 +329,24 @@ namespace ts.server {
                     return;
                 case 1:
                     if (this.containingProjects[0] === project) {
+                        project.hasMoreOrLessScriptInfos = true;
                         this.containingProjects.pop();
                     }
                     break;
                 case 2:
                     if (this.containingProjects[0] === project) {
+                        project.hasMoreOrLessScriptInfos = true;
                         this.containingProjects[0] = this.containingProjects.pop();
                     }
                     else if (this.containingProjects[1] === project) {
+                        project.hasMoreOrLessScriptInfos = true;
                         this.containingProjects.pop();
                     }
                     break;
                 default:
-                    unorderedRemoveItem(this.containingProjects, project);
+                    if (unorderedRemoveItem(this.containingProjects, project)) {
+                        project.hasMoreOrLessScriptInfos = true;
+                    }
                     break;
             }
         }