Use native private members in rush-lib

common/changes/@rushstack/eslint-plugin/native-private-null_2026-08-19-22-58-08.json

@@ -0,0 +1,9 @@
+{
+  "changes": [
+    {
+      "packageName": "@rushstack/eslint-plugin",
+      "comment": "Fix no-new-null false positives for ECMAScript private class members.",
+      "type": "patch"
+    }
+  ]
+}

eslint/eslint-plugin/src/no-new-null.ts

@@ -9,6 +9,7 @@ type Options = [];
 
 interface IAccessible {
   accessibility?: TSESTree.Accessibility;
+  key?: TSESTree.Node;
 }
 
 const noNewNullRule: TSESLint.RuleModule<MessageIds, Options> = {
@@ -37,11 +38,15 @@ const noNewNullRule: TSESLint.RuleModule<MessageIds, Options> = {
 
   create: (context: TSESLint.RuleContext<MessageIds, Options>) => {
     /**
-     * Returns true if the accessibility is not explicitly set to private or protected, e.g. class properties, methods.
+     * Returns true unless a class member uses protected, TypeScript-private, or ECMAScript-private syntax.
      */
     function isPubliclyAccessible(node?: IAccessible): boolean {
       const accessibility: TSESTree.Accessibility | undefined = node?.accessibility;
-      return !(accessibility === 'private' || accessibility === 'protected');
+      return (
+        accessibility !== 'private' &&
+        accessibility !== 'protected' &&
+        node?.key?.type !== AST_NODE_TYPES.PrivateIdentifier
+      );
     }
 
     /**

eslint/eslint-plugin/src/test/no-new-null.test.ts

@@ -104,6 +104,17 @@ ruleTester.run('no-new-null', noNewNullRule, {
         '  }',
         '}'
       ].join('\n')
+    },
+    {
+      code: [
+        'class NativePrivateNulls {',
+        '  #field: string | null;',
+        '  #propertyFunc: (value: string | null) => void;',
+        '  #method(value: string | null): string | null { return value; }',
+        '  get #value(): string | null { return this.#field; }',
+        '  set #value(value: string | null) { this.#field = value; }',
+        '}'
+      ].join('\n')
     }
   ]
 });

libraries/rush-lib/src/api/ApprovedPackagesConfiguration.ts

@@ -59,39 +59,39 @@ const _jsonSchema: JsonSchema = JsonSchema.fromLoadedObject(schemaJson);
 export class ApprovedPackagesConfiguration {
   public items: ApprovedPackagesItem[] = [];
 
-  private _itemsByName: Map<string, ApprovedPackagesItem> = new Map<string, ApprovedPackagesItem>();
+  #itemsByName: Map<string, ApprovedPackagesItem> = new Map<string, ApprovedPackagesItem>();
 
-  private _loadedJson!: IApprovedPackagesJson;
-  private _jsonFilename: string;
+  #loadedJson!: IApprovedPackagesJson;
+  #jsonFilename: string;
 
   public constructor(jsonFilename: string) {
-    this._jsonFilename = jsonFilename;
+    this.#jsonFilename = jsonFilename;
     this.clear();
   }
 
   /**
    * Clears all the settings, returning to an empty state.
    */
   public clear(): void {
-    this._itemsByName.clear();
-    this._loadedJson = {
+    this.#itemsByName.clear();
+    this.#loadedJson = {
       // Ensure this comes first in the key ordering
       $schema: '',
       packages: []
     };
   }
 
   public getItemByName(packageName: string): ApprovedPackagesItem | undefined {
-    return this._itemsByName.get(packageName);
+    return this.#itemsByName.get(packageName);
   }
 
   public addOrUpdatePackage(packageName: string, reviewCategory: string): boolean {
     let changed: boolean = false;
 
-    let item: ApprovedPackagesItem | undefined = this._itemsByName.get(packageName);
+    let item: ApprovedPackagesItem | undefined = this.#itemsByName.get(packageName);
     if (!item) {
       item = new ApprovedPackagesItem(packageName);
-      this._addItem(item);
+      this.#addItem(item);
       changed = true;
     }
 
@@ -107,7 +107,7 @@ export class ApprovedPackagesConfiguration {
    * If the file exists, calls loadFromFile().
    */
   public tryLoadFromFile(approvedPackagesPolicyEnabled: boolean): boolean {
-    if (!FileSystem.exists(this._jsonFilename)) {
+    if (!FileSystem.exists(this.#jsonFilename)) {
       return false;
     }
 
@@ -116,7 +116,7 @@ export class ApprovedPackagesConfiguration {
     if (!approvedPackagesPolicyEnabled) {
       // eslint-disable-next-line no-console
       console.log(
-        `Warning: Ignoring "${path.basename(this._jsonFilename)}" because the` +
+        `Warning: Ignoring "${path.basename(this.#jsonFilename)}" because the` +
           ` "approvedPackagesPolicy" setting was not specified in ${RushConstants.rushJsonFilename}`
       );
     }
@@ -129,14 +129,14 @@ export class ApprovedPackagesConfiguration {
    */
   public loadFromFile(): void {
     const approvedPackagesJson: IApprovedPackagesJson = JsonFile.loadAndValidate(
-      this._jsonFilename,
+      this.#jsonFilename,
       _jsonSchema
     );
 
     this.clear();
 
     for (const browserPackage of approvedPackagesJson.packages) {
-      this._addItemJson(browserPackage, this._jsonFilename);
+      this.#addItemJson(browserPackage, this.#jsonFilename);
     }
   }
 
@@ -148,9 +148,9 @@ export class ApprovedPackagesConfiguration {
     // (which passed schema validation).
 
     // eslint-disable-next-line dot-notation
-    this._loadedJson['$schema'] = JsonSchemaUrls.approvedPackages;
+    this.#loadedJson['$schema'] = JsonSchemaUrls.approvedPackages;
 
-    this._loadedJson.packages = [];
+    this.#loadedJson.packages = [];
 
     this.items.sort((a: ApprovedPackagesItem, b: ApprovedPackagesItem) => {
       return a.packageName.localeCompare(b.packageName);
@@ -166,11 +166,11 @@ export class ApprovedPackagesConfiguration {
         allowedCategories: allowedCategories
       };
 
-      this._loadedJson.packages.push(itemJson);
+      this.#loadedJson.packages.push(itemJson);
     }
 
     // Save the file
-    let body: string = JsonFile.stringify(this._loadedJson);
+    let body: string = JsonFile.stringify(this.#loadedJson);
 
     // Unindent the allowedCategories array to improve readability
     body = body.replace(/("allowedCategories": +\[)([^\]]+)/g, (substring: string, ...args: string[]) => {
@@ -180,16 +180,16 @@ export class ApprovedPackagesConfiguration {
     // Add a header
     body = '// DO NOT ADD COMMENTS IN THIS FILE.  They will be lost when the Rush tool resaves it.\n' + body;
 
-    FileSystem.writeFile(this._jsonFilename, body, {
+    FileSystem.writeFile(this.#jsonFilename, body, {
       convertLineEndings: NewlineKind.CrLf
     });
   }
 
   /**
    * Helper function only used by the constructor when loading the file.
    */
-  private _addItemJson(itemJson: IApprovedPackagesItemJson, jsonFilename: string): void {
-    if (this._itemsByName.has(itemJson.name)) {
+  #addItemJson(itemJson: IApprovedPackagesItemJson, jsonFilename: string): void {
+    if (this.#itemsByName.has(itemJson.name)) {
       throw new Error(
         `Error loading package review file ${jsonFilename}:\n` +
           ` the name "${itemJson.name}" appears more than once`
@@ -202,18 +202,18 @@ export class ApprovedPackagesConfiguration {
         item.allowedCategories.add(allowedCategory);
       }
     }
-    this._addItem(item);
+    this.#addItem(item);
   }
 
   /**
    * Helper function that adds an already created ApprovedPackagesItem to the
    * list and set.
    */
-  private _addItem(item: ApprovedPackagesItem): void {
-    if (this._itemsByName.has(item.packageName)) {
+  #addItem(item: ApprovedPackagesItem): void {
+    if (this.#itemsByName.has(item.packageName)) {
       throw new InternalError('Duplicate key');
     }
     this.items.push(item);
-    this._itemsByName.set(item.packageName, item);
+    this.#itemsByName.set(item.packageName, item);
   }
 }

libraries/rush-lib/src/api/ChangeFile.ts

@@ -15,8 +15,8 @@ import { Git } from '../logic/Git';
  * This class represents a single change file.
  */
 export class ChangeFile {
-  private _changeFileData: IChangeFile;
-  private _rushConfiguration: RushConfiguration;
+  #changeFileData: IChangeFile;
+  #rushConfiguration: RushConfiguration;
 
   /**
    * @internal
@@ -30,16 +30,16 @@ export class ChangeFile {
       throw new Error(`rushConfiguration does not have a value`);
     }
 
-    this._changeFileData = changeFileData;
-    this._rushConfiguration = rushConfiguration;
+    this.#changeFileData = changeFileData;
+    this.#rushConfiguration = rushConfiguration;
   }
 
   /**
    * Adds a change entry into the change file
    * @param data - change information
    */
   public addChange(data: IChangeInfo): void {
-    this._changeFileData.changes.push(data);
+    this.#changeFileData.changes.push(data);
   }
 
   /**
@@ -48,7 +48,7 @@ export class ChangeFile {
    */
   public getChanges(packageName: string): IChangeInfo[] {
     const changes: IChangeInfo[] = [];
-    for (const info of this._changeFileData.changes) {
+    for (const info of this.#changeFileData.changes) {
       if (info.packageName === packageName) {
         changes.push(info);
       }
@@ -63,7 +63,7 @@ export class ChangeFile {
    */
   public writeSync(): string {
     const filePath: string = this.generatePath();
-    JsonFile.save(this._changeFileData, filePath, {
+    JsonFile.save(this.#changeFileData, filePath, {
       ensureFolderExists: true
     });
     return filePath;
@@ -76,7 +76,7 @@ export class ChangeFile {
    */
   public generatePath(): string {
     let branch: string | undefined = undefined;
-    const git: Git = new Git(this._rushConfiguration);
+    const git: Git = new Git(this.#rushConfiguration);
     const repoInfo: gitInfo.GitRepoInfo | undefined = git.getGitInfo();
     branch = repoInfo && repoInfo.branch;
     if (!branch) {
@@ -89,13 +89,13 @@ export class ChangeFile {
     // flag rarely had any effect, and a second invocation would silently clobber the
     // change file written by the first one. See GitHub issue #2195.
     // example filename: yourbranchname_2017-05-01-20-20-30.json
-    const timestamp: string | undefined = this._getTimestamp(true);
+    const timestamp: string | undefined = this.#getTimestamp(true);
     const filename: string = branch
-      ? this._escapeFilename(`${branch}_${timestamp}.json`)
+      ? this.#escapeFilename(`${branch}_${timestamp}.json`)
       : `${timestamp}.json`;
     const filePath: string = path.join(
-      this._rushConfiguration.changesFolder,
-      ...this._changeFileData.packageName.split('/'),
+      this.#rushConfiguration.changesFolder,
+      ...this.#changeFileData.packageName.split('/'),
       filename
     );
     return filePath;
@@ -105,7 +105,7 @@ export class ChangeFile {
    * Gets the current time, formatted as YYYY-MM-DD-HH-MM
    * When useSeconds is true, the seconds are appended as well: YYYY-MM-DD-HH-MM-SS
    */
-  private _getTimestamp(useSeconds: boolean = false): string | undefined {
+  #getTimestamp(useSeconds: boolean = false): string | undefined {
     // Create a date string with the current time
 
     // dateString === "2016-10-19T22:47:49.606Z"
@@ -137,7 +137,7 @@ export class ChangeFile {
     return undefined;
   }
 
-  private _escapeFilename(filename: string, replacer: string = '-'): string {
+  #escapeFilename(filename: string, replacer: string = '-'): string {
     // Removes / ? < > \ : * | ", really anything that isn't a letter, number, '.' '_' or '-'
     const badCharacters: RegExp = /[^a-zA-Z0-9._-]/g;
     return filename.replace(badCharacters, replacer);

libraries/rush-lib/src/api/CobuildConfiguration.ts

@@ -76,9 +76,9 @@ export class CobuildConfiguration {
    */
   public readonly cobuildWithoutCacheAllowed: boolean;
 
-  private _cobuildLockProvider: ICobuildLockProvider | undefined;
-  private readonly _cobuildLockProviderFactory: CobuildLockProviderFactory;
-  private readonly _cobuildJson: ICobuildJson;
+  #cobuildLockProvider: ICobuildLockProvider | undefined;
+  readonly #cobuildLockProviderFactory: CobuildLockProviderFactory;
+  readonly #cobuildJson: ICobuildJson;
 
   private constructor(options: ICobuildConfigurationOptions) {
     const { cobuildJson, cobuildLockProviderFactory, rushConfiguration } = options;
@@ -91,8 +91,8 @@ export class CobuildConfiguration {
     this.cobuildWithoutCacheAllowed =
       rushConfiguration.experimentsConfiguration.configuration.allowCobuildWithoutCache ?? false;
 
-    this._cobuildLockProviderFactory = cobuildLockProviderFactory;
-    this._cobuildJson = cobuildJson;
+    this.#cobuildLockProviderFactory = cobuildLockProviderFactory;
+    this.#cobuildJson = cobuildJson;
   }
 
   /**
@@ -127,25 +127,25 @@ export class CobuildConfiguration {
   public async createLockProviderAsync(terminal: ITerminal): Promise<void> {
     if (this.cobuildFeatureEnabled) {
       terminal.writeLine(`Running cobuild (runner ${this.cobuildContextId}/${this.cobuildRunnerId})`);
-      const cobuildLockProvider: ICobuildLockProvider = await this._cobuildLockProviderFactory(
-        this._cobuildJson
+      const cobuildLockProvider: ICobuildLockProvider = await this.#cobuildLockProviderFactory(
+        this.#cobuildJson
       );
-      this._cobuildLockProvider = cobuildLockProvider;
-      await this._cobuildLockProvider.connectAsync();
+      this.#cobuildLockProvider = cobuildLockProvider;
+      await this.#cobuildLockProvider.connectAsync();
     }
   }
 
   public async destroyLockProviderAsync(): Promise<void> {
     if (this.cobuildFeatureEnabled) {
-      await this._cobuildLockProvider?.disconnectAsync();
+      await this.#cobuildLockProvider?.disconnectAsync();
     }
   }
 
   public getCobuildLockProvider(): ICobuildLockProvider {
-    if (!this._cobuildLockProvider) {
+    if (!this.#cobuildLockProvider) {
       throw new Error(`Cobuild lock provider has not been created`);
     }
-    return this._cobuildLockProvider;
+    return this.#cobuildLockProvider;
   }
 }