Enable eslint rules prefer-rest-params and prefer-spread

.eslintrc.json

@@ -104,8 +104,6 @@
         ],
 
         // Todo: For each of these, investigate whether we want to enable them ✨
-        "prefer-rest-params": "off",
-        "prefer-spread": "off",
         "@typescript-eslint/no-unused-vars": "off",
 
         // Pending https://github.com/typescript-eslint/typescript-eslint/issues/4820

src/compiler/checker.ts

@@ -19844,7 +19844,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 const childrenPropName = childPropName === undefined ? "children" : unescapeLeadingUnderscores(childPropName);
                 const childrenTargetType = getIndexedAccessType(target, getStringLiteralType(childrenPropName));
                 const diagnostic = Diagnostics._0_components_don_t_accept_text_as_child_elements_Text_in_JSX_has_the_type_string_but_the_expected_type_of_1_is_2;
-                invalidTextDiagnostic = { ...diagnostic, key: "!!ALREADY FORMATTED!!", message: formatMessage(/*dummy*/ undefined, diagnostic, tagNameText, childrenPropName, typeToString(childrenTargetType)) };
+                invalidTextDiagnostic = { ...diagnostic, key: "!!ALREADY FORMATTED!!", message: formatMessage(diagnostic, tagNameText, childrenPropName, typeToString(childrenTargetType)) };
             }
             return invalidTextDiagnostic;
         }

src/compiler/commandLineParser.ts

@@ -6,6 +6,7 @@ import {
     arrayToMap,
     assign,
     BuildOptions,
+    cast,
     changeExtension,
     CharacterCodes,
     combinePaths,
@@ -2018,9 +2019,8 @@ export function parseBuildCommand(args: readonly string[]): ParsedBuildCommand {
 }
 
 /** @internal */
-export function getDiagnosticText(_message: DiagnosticMessage, ..._args: any[]): string {
-    const diagnostic = createCompilerDiagnostic.apply(undefined, arguments);
-    return diagnostic.messageText as string;
+export function getDiagnosticText(message: DiagnosticMessage, ...args: any[]): string {
+    return cast(createCompilerDiagnostic(message, ...args).messageText, isString);
 }
 
 export type DiagnosticReporter = (diagnostic: Diagnostic) => void;

src/compiler/core.ts

@@ -2061,6 +2061,7 @@ export function compose<T>(a: (t: T) => T, b: (t: T) => T, c: (t: T) => T, d: (t
     if (!!e) {
         const args: ((t: T) => T)[] = [];
         for (let i = 0; i < arguments.length; i++) {
+            // eslint-disable-next-line prefer-rest-params
             args[i] = arguments[i];
         }
 

src/compiler/moduleNameResolver.ts

@@ -115,9 +115,8 @@ import {
 } from "./_namespaces/ts";
 
 /** @internal */
-export function trace(host: ModuleResolutionHost, message: DiagnosticMessage, ...args: any[]): void;
-export function trace(host: ModuleResolutionHost): void {
-    host.trace!(formatMessage.apply(undefined, arguments));
+export function trace(host: ModuleResolutionHost, message: DiagnosticMessage, ...args: any[]): void {
+    host.trace!(formatMessage(message, ...args));
 }
 
 /** @internal */

src/compiler/utilities.ts

@@ -8121,8 +8121,8 @@ export function setObjectAllocator(alloc: ObjectAllocator) {
 }
 
 /** @internal */
-export function formatStringFromArgs(text: string, args: ArrayLike<string | number>, baseIndex = 0): string {
-    return text.replace(/{(\d+)}/g, (_match, index: string) => "" + Debug.checkDefined(args[+index + baseIndex]));
+export function formatStringFromArgs(text: string, args: DiagnosticArguments): string {
+    return text.replace(/{(\d+)}/g, (_match, index: string) => "" + Debug.checkDefined(args[+index]));
 }
 
 let localizedDiagnosticMessages: MapLike<string> | undefined;
@@ -8147,14 +8147,12 @@ export function getLocaleSpecificMessage(message: DiagnosticMessage) {
 }
 
 /** @internal */
-export function createDetachedDiagnostic(fileName: string, start: number, length: number, message: DiagnosticMessage, ...args: DiagnosticArguments): DiagnosticWithDetachedLocation;
-/** @internal */
-export function createDetachedDiagnostic(fileName: string, start: number, length: number, message: DiagnosticMessage): DiagnosticWithDetachedLocation {
+export function createDetachedDiagnostic(fileName: string, start: number, length: number, message: DiagnosticMessage, ...args: DiagnosticArguments): DiagnosticWithDetachedLocation {
     assertDiagnosticLocation(/*file*/ undefined, start, length);
     let text = getLocaleSpecificMessage(message);
 
-    if (arguments.length > 4) {
-        text = formatStringFromArgs(text, arguments, 4);
+    if (some(args)) {
+        text = formatStringFromArgs(text, args);
     }
 
     return {
@@ -8218,15 +8216,13 @@ export function attachFileToDiagnostics(diagnostics: DiagnosticWithDetachedLocat
 }
 
 /** @internal */
-export function createFileDiagnostic(file: SourceFile, start: number, length: number, message: DiagnosticMessage, ...args: DiagnosticArguments): DiagnosticWithLocation;
-/** @internal */
-export function createFileDiagnostic(file: SourceFile, start: number, length: number, message: DiagnosticMessage): DiagnosticWithLocation {
+export function createFileDiagnostic(file: SourceFile, start: number, length: number, message: DiagnosticMessage, ...args: DiagnosticArguments): DiagnosticWithLocation {
     assertDiagnosticLocation(file, start, length);
 
     let text = getLocaleSpecificMessage(message);
 
-    if (arguments.length > 4) {
-        text = formatStringFromArgs(text, arguments, 4);
+    if (some(args)) {
+        text = formatStringFromArgs(text, args);
     }
 
     return {
@@ -8243,26 +8239,22 @@ export function createFileDiagnostic(file: SourceFile, start: number, length: nu
 }
 
 /** @internal */
-export function formatMessage(_dummy: any, message: DiagnosticMessage, ...args: DiagnosticArguments): string;
-/** @internal */
-export function formatMessage(_dummy: any, message: DiagnosticMessage): string {
+export function formatMessage(message: DiagnosticMessage, ...args: DiagnosticArguments): string {
     let text = getLocaleSpecificMessage(message);
 
-    if (arguments.length > 2) {
-        text = formatStringFromArgs(text, arguments, 2);
+    if (some(args)) {
+        text = formatStringFromArgs(text, args);
     }
 
     return text;
 }
 
 /** @internal */
-export function createCompilerDiagnostic(message: DiagnosticMessage, ...args: DiagnosticArguments): Diagnostic;
-/** @internal */
-export function createCompilerDiagnostic(message: DiagnosticMessage): Diagnostic {
+export function createCompilerDiagnostic(message: DiagnosticMessage, ...args: DiagnosticArguments): Diagnostic {
     let text = getLocaleSpecificMessage(message);
 
-    if (arguments.length > 1) {
-        text = formatStringFromArgs(text, arguments, 1);
+    if (some(args)) {
+        text = formatStringFromArgs(text, args);
     }
 
     return {
@@ -8293,13 +8285,11 @@ export function createCompilerDiagnosticFromMessageChain(chain: DiagnosticMessag
 }
 
 /** @internal */
-export function chainDiagnosticMessages(details: DiagnosticMessageChain | DiagnosticMessageChain[] | undefined, message: DiagnosticMessage, ...args: DiagnosticArguments): DiagnosticMessageChain;
-/** @internal */
-export function chainDiagnosticMessages(details: DiagnosticMessageChain | DiagnosticMessageChain[] | undefined, message: DiagnosticMessage): DiagnosticMessageChain {
+export function chainDiagnosticMessages(details: DiagnosticMessageChain | DiagnosticMessageChain[] | undefined, message: DiagnosticMessage, ...args: DiagnosticArguments): DiagnosticMessageChain {
     let text = getLocaleSpecificMessage(message);
 
-    if (arguments.length > 2) {
-        text = formatStringFromArgs(text, arguments, 2);
+    if (some(args)) {
+        text = formatStringFromArgs(text, args);
     }
     return {
         messageText: text,

src/deprecatedCompat/deprecate.ts

@@ -24,7 +24,7 @@ function formatDeprecationMessage(name: string, error: boolean | undefined, erro
     deprecationMessage += `'${name}' `;
     deprecationMessage += since ? `has been deprecated since v${since}` : "is deprecated";
     deprecationMessage += error ? " and can no longer be used." : errorAfter ? ` and will no longer be usable after v${errorAfter}.` : ".";
-    deprecationMessage += message ? ` ${formatStringFromArgs(message, [name], 0)}` : "";
+    deprecationMessage += message ? ` ${formatStringFromArgs(message, [name])}` : "";
     return deprecationMessage;
 }
 
@@ -62,6 +62,7 @@ export function createDeprecation(name: string, options: DeprecationOptions = {}
 function wrapFunction<F extends (...args: any[]) => any>(deprecation: () => void, func: F): F {
     return function (this: unknown) {
         deprecation();
+        // eslint-disable-next-line prefer-rest-params
         return func.apply(this, arguments);
     } as F;
 }

src/executeCommandLine/executeCommandLine.ts

@@ -486,7 +486,7 @@ function printEasyHelp(sys: System, simpleOptions: readonly CommandLineOption[])
     output = [
         ...output,
         ...generateSectionOptionsOutput(sys, getDiagnosticText(Diagnostics.COMMAND_LINE_FLAGS), cliCommands, /*subCategory*/ false, /*beforeOptionsDescription*/ undefined, /*afterOptionsDescription*/ undefined),
-        ...generateSectionOptionsOutput(sys, getDiagnosticText(Diagnostics.COMMON_COMPILER_OPTIONS), configOpts, /*subCategory*/ false, /*beforeOptionsDescription*/ undefined, formatMessage(/*dummy*/ undefined, Diagnostics.You_can_learn_about_all_of_the_compiler_options_at_0, "https://aka.ms/tsc"))
+        ...generateSectionOptionsOutput(sys, getDiagnosticText(Diagnostics.COMMON_COMPILER_OPTIONS), configOpts, /*subCategory*/ false, /*beforeOptionsDescription*/ undefined, formatMessage(Diagnostics.You_can_learn_about_all_of_the_compiler_options_at_0, "https://aka.ms/tsc"))
     ];
 
     for (const line of output) {
@@ -504,17 +504,17 @@ function printEasyHelp(sys: System, simpleOptions: readonly CommandLineOption[])
 
 function printAllHelp(sys: System, compilerOptions: readonly CommandLineOption[], buildOptions: readonly CommandLineOption[], watchOptions: readonly CommandLineOption[]) {
     let output: string[] = [...getHeader(sys,`${getDiagnosticText(Diagnostics.tsc_Colon_The_TypeScript_Compiler)} - ${getDiagnosticText(Diagnostics.Version_0, version)}`)];
-    output = [...output, ...generateSectionOptionsOutput(sys, getDiagnosticText(Diagnostics.ALL_COMPILER_OPTIONS), compilerOptions, /*subCategory*/ true, /*beforeOptionsDescription*/ undefined, formatMessage(/*dummy*/ undefined, Diagnostics.You_can_learn_about_all_of_the_compiler_options_at_0, "https://aka.ms/tsc"))];
+    output = [...output, ...generateSectionOptionsOutput(sys, getDiagnosticText(Diagnostics.ALL_COMPILER_OPTIONS), compilerOptions, /*subCategory*/ true, /*beforeOptionsDescription*/ undefined, formatMessage(Diagnostics.You_can_learn_about_all_of_the_compiler_options_at_0, "https://aka.ms/tsc"))];
     output = [...output, ...generateSectionOptionsOutput(sys, getDiagnosticText(Diagnostics.WATCH_OPTIONS), watchOptions, /*subCategory*/ false, getDiagnosticText(Diagnostics.Including_watch_w_will_start_watching_the_current_project_for_the_file_changes_Once_set_you_can_config_watch_mode_with_Colon))];
-    output = [...output, ...generateSectionOptionsOutput(sys, getDiagnosticText(Diagnostics.BUILD_OPTIONS), buildOptions, /*subCategory*/ false, formatMessage(/*dummy*/ undefined, Diagnostics.Using_build_b_will_make_tsc_behave_more_like_a_build_orchestrator_than_a_compiler_This_is_used_to_trigger_building_composite_projects_which_you_can_learn_more_about_at_0, "https://aka.ms/tsc-composite-builds"))];
+    output = [...output, ...generateSectionOptionsOutput(sys, getDiagnosticText(Diagnostics.BUILD_OPTIONS), buildOptions, /*subCategory*/ false, formatMessage(Diagnostics.Using_build_b_will_make_tsc_behave_more_like_a_build_orchestrator_than_a_compiler_This_is_used_to_trigger_building_composite_projects_which_you_can_learn_more_about_at_0, "https://aka.ms/tsc-composite-builds"))];
     for (const line of output) {
         sys.write(line);
     }
 }
 
 function printBuildHelp(sys: System, buildOptions: readonly CommandLineOption[]) {
     let output: string[] = [...getHeader(sys,`${getDiagnosticText(Diagnostics.tsc_Colon_The_TypeScript_Compiler)} - ${getDiagnosticText(Diagnostics.Version_0, version)}`)];
-    output = [...output, ...generateSectionOptionsOutput(sys, getDiagnosticText(Diagnostics.BUILD_OPTIONS), buildOptions, /*subCategory*/ false, formatMessage(/*dummy*/ undefined, Diagnostics.Using_build_b_will_make_tsc_behave_more_like_a_build_orchestrator_than_a_compiler_This_is_used_to_trigger_building_composite_projects_which_you_can_learn_more_about_at_0, "https://aka.ms/tsc-composite-builds"))];
+    output = [...output, ...generateSectionOptionsOutput(sys, getDiagnosticText(Diagnostics.BUILD_OPTIONS), buildOptions, /*subCategory*/ false, formatMessage(Diagnostics.Using_build_b_will_make_tsc_behave_more_like_a_build_orchestrator_than_a_compiler_This_is_used_to_trigger_building_composite_projects_which_you_can_learn_more_about_at_0, "https://aka.ms/tsc-composite-builds"))];
     for (const line of output) {
         sys.write(line);
     }

src/harness/fourslashImpl.ts

@@ -3279,7 +3279,7 @@ export class TestState {
             assert.equal(action.description, options.description);
         }
         else if (Array.isArray(options.description)) {
-            const description = ts.formatStringFromArgs(options.description[0], options.description, 1);
+            const description = ts.formatStringFromArgs(options.description[0], options.description.slice(1));
             assert.equal(action.description, description);
         }
         else {
@@ -4333,7 +4333,7 @@ export class TestState {
     public toggleLineComment(newFileContent: string): void {
         const changes: ts.TextChange[] = [];
         for (const range of this.getRanges()) {
-            changes.push.apply(changes, this.languageService.toggleLineComment(this.activeFile.fileName, range));
+            changes.push(...this.languageService.toggleLineComment(this.activeFile.fileName, range));
         }
 
         this.applyEdits(this.activeFile.fileName, changes);
@@ -4344,7 +4344,7 @@ export class TestState {
     public toggleMultilineComment(newFileContent: string): void {
         const changes: ts.TextChange[] = [];
         for (const range of this.getRanges()) {
-            changes.push.apply(changes, this.languageService.toggleMultilineComment(this.activeFile.fileName, range));
+            changes.push(...this.languageService.toggleMultilineComment(this.activeFile.fileName, range));
         }
 
         this.applyEdits(this.activeFile.fileName, changes);
@@ -4355,7 +4355,7 @@ export class TestState {
     public commentSelection(newFileContent: string): void {
         const changes: ts.TextChange[] = [];
         for (const range of this.getRanges()) {
-            changes.push.apply(changes, this.languageService.commentSelection(this.activeFile.fileName, range));
+            changes.push(...this.languageService.commentSelection(this.activeFile.fileName, range));
         }
 
         this.applyEdits(this.activeFile.fileName, changes);
@@ -4366,7 +4366,7 @@ export class TestState {
     public uncommentSelection(newFileContent: string): void {
         const changes: ts.TextChange[] = [];
         for (const range of this.getRanges()) {
-            changes.push.apply(changes, this.languageService.uncommentSelection(this.activeFile.fileName, range));
+            changes.push(...this.languageService.uncommentSelection(this.activeFile.fileName, range));
         }
 
         this.applyEdits(this.activeFile.fileName, changes);

src/harness/harnessLanguageService.ts

@@ -17,6 +17,7 @@ export function makeDefaultProxy(info: ts.server.PluginCreateInfo): ts.LanguageS
     for (const k of Object.keys(langSvc)) {
         // eslint-disable-next-line local/only-arrow-functions
         proxy[k] = function () {
+            // eslint-disable-next-line prefer-spread, prefer-rest-params
             return langSvc[k].apply(langSvc, arguments);
         };
     }
@@ -901,6 +902,7 @@ class SessionServerHost implements ts.server.ServerHost, ts.server.Logger {
                             const langSvc: any = info.languageService;
                             // eslint-disable-next-line local/only-arrow-functions
                             proxy.getQuickInfoAtPosition = function () {
+                                // eslint-disable-next-line prefer-spread, prefer-rest-params
                                 const parts = langSvc.getQuickInfoAtPosition.apply(langSvc, arguments);
                                 if (parts.displayParts.length > 0) {
                                     parts.displayParts[0].text = "Proxied";

src/services/services.ts

@@ -2614,7 +2614,7 @@ export function createLanguageService(
             // If the line is not an empty line; otherwise no-op.
             if (lineTextStart !== undefined) {
                 if (isJsx) {
-                    textChanges.push.apply(textChanges, toggleMultilineComment(fileName, { pos: lineStarts[i] + leftMostPosition, end: sourceFile.getLineEndOfPosition(lineStarts[i]) }, isCommenting, isJsx));
+                    textChanges.push(...toggleMultilineComment(fileName, { pos: lineStarts[i] + leftMostPosition, end: sourceFile.getLineEndOfPosition(lineStarts[i]) }, isCommenting, isJsx));
                 }
                 else if (isCommenting) {
                     textChanges.push({
@@ -2788,10 +2788,10 @@ export function createLanguageService(
             if (commentRange) {
                 switch (commentRange.kind) {
                     case SyntaxKind.SingleLineCommentTrivia:
-                        textChanges.push.apply(textChanges, toggleLineComment(fileName, { end: commentRange.end, pos: commentRange.pos + 1 }, /*insertComment*/ false));
+                        textChanges.push(...toggleLineComment(fileName, { end: commentRange.end, pos: commentRange.pos + 1 }, /*insertComment*/ false));
                         break;
                     case SyntaxKind.MultiLineCommentTrivia:
-                        textChanges.push.apply(textChanges, toggleMultilineComment(fileName, { end: commentRange.end, pos: commentRange.pos + 1 }, /*insertComment*/ false));
+                        textChanges.push(...toggleMultilineComment(fileName, { end: commentRange.end, pos: commentRange.pos + 1 }, /*insertComment*/ false));
                 }
 
                 i = commentRange.end + 1;