JsTyping: Remove "safeList" global variable (#17304)

src/services/jsTyping.ts

@@ -25,10 +25,6 @@ namespace ts.JsTyping {
         typings?: string;
     }
 
-    // A map of loose file names to library names
-    // that we are confident require typings
-    let safeList: Map<string>;
-
     /* @internal */
     export const nodeCoreModuleList: ReadonlyArray<string> = [
         "buffer", "querystring", "events", "http", "cluster",
@@ -40,6 +36,16 @@ namespace ts.JsTyping {
 
     const nodeCoreModules = arrayToMap(<string[]>nodeCoreModuleList, x => x);
 
+    /**
+     * A map of loose file names to library names that we are confident require typings
+     */
+    export type SafeList = ReadonlyMap<string>;
+
+    export function loadSafeList(host: TypingResolutionHost, safeListPath: Path): SafeList {
+        const result = readConfigFile(safeListPath, path => host.readFile(path));
+        return createMapFromTemplate<string>(result.config);
+    }
+
     /**
      * @param host is the object providing I/O related operations.
      * @param fileNames are the file names that belong to the same project
@@ -54,8 +60,8 @@ namespace ts.JsTyping {
         log: ((message: string) => void) | undefined,
         fileNames: string[],
         projectRootPath: Path,
-        safeListPath: Path,
-        packageNameToTypingLocation: Map<string>,
+        safeList: SafeList,
+        packageNameToTypingLocation: ReadonlyMap<string>,
         typeAcquisition: TypeAcquisition,
         unresolvedImports: ReadonlyArray<string>):
         { cachedTypingPaths: string[], newTypingNames: string[], filesToWatch: string[] } {
@@ -75,11 +81,6 @@ namespace ts.JsTyping {
             }
         });
 
-        if (!safeList) {
-            const result = readConfigFile(safeListPath, (path: string) => host.readFile(path));
-            safeList = createMapFromTemplate<string>(result.config);
-        }
-
         const filesToWatch: string[] = [];
 
         forEach(typeAcquisition.include, addInferredTyping);

src/services/shims.ts

@@ -1005,6 +1005,7 @@ namespace ts {
 
     class CoreServicesShimObject extends ShimBase implements CoreServicesShim {
         private logPerformance = false;
+        private safeList: JsTyping.SafeList | undefined;
 
         constructor(factory: ShimFactory, public readonly logger: Logger, private readonly host: CoreServicesShimHostAdapter) {
             super(factory);
@@ -1114,12 +1115,15 @@ namespace ts {
             const getCanonicalFileName = createGetCanonicalFileName(/*useCaseSensitivefileNames:*/ false);
             return this.forwardJSONCall("discoverTypings()", () => {
                 const info = <DiscoverTypingsInfo>JSON.parse(discoverTypingsJson);
-                return ts.JsTyping.discoverTypings(
+                if (this.safeList === undefined) {
+                    this.safeList = JsTyping.loadSafeList(this.host, toPath(info.safeListPath, info.safeListPath, getCanonicalFileName));
+                }
+                return JsTyping.discoverTypings(
                     this.host,
                     msg => this.logger.log(msg),
                     info.fileNames,
                     toPath(info.projectRootPath, info.projectRootPath, getCanonicalFileName),
-                    toPath(info.safeListPath, info.safeListPath, getCanonicalFileName),
+                    this.safeList,
                     info.packageNameToTypingLocation,
                     info.typeAcquisition,
                     info.unresolvedImports);