Add option for organize imports case sensitivity (#51733)

* Add ignore case option to organizeImports

* Adopt in auto-imports, use same case-insensitive comparison as eslint

* Fix build/lint

* Mark functions internal

* Update affected auto import test

* Update API baseline

* Update protocol

* Update API baseline

* Short-circuit comparisons that have already failed

src/compiler/core.ts

@@ -944,16 +944,53 @@ export function sortAndDeduplicate<T>(array: readonly T[], comparer?: Comparer<T
 /** @internal */
 export function arrayIsSorted<T>(array: readonly T[], comparer: Comparer<T>) {
     if (array.length < 2) return true;
-    let prevElement = array[0];
-    for (const element of array.slice(1)) {
-        if (comparer(prevElement, element) === Comparison.GreaterThan) {
+    for (let i = 1, len = array.length; i < len; i++) {
+        if (comparer(array[i - 1], array[i]) === Comparison.GreaterThan) {
             return false;
         }
-        prevElement = element;
     }
     return true;
 }
 
+/** @internal */
+export const enum SortKind {
+    None = 0,
+    CaseSensitive = 1 << 0,
+    CaseInsensitive = 1 << 1,
+    Both = CaseSensitive | CaseInsensitive,
+}
+
+/** @internal */
+export function detectSortCaseSensitivity(array: readonly string[], useEslintOrdering?: boolean): SortKind;
+/** @internal */
+export function detectSortCaseSensitivity<T>(array: readonly T[], useEslintOrdering: boolean, getString: (element: T) => string): SortKind;
+/** @internal */
+export function detectSortCaseSensitivity<T>(array: readonly T[], useEslintOrdering: boolean, getString?: (element: T) => string): SortKind {
+    let kind = SortKind.Both;
+    if (array.length < 2) return kind;
+    const caseSensitiveComparer = getString
+        ? (a: T, b: T) => compareStringsCaseSensitive(getString(a), getString(b))
+        : compareStringsCaseSensitive as (a: T | undefined, b: T | undefined) => Comparison;
+    const compareCaseInsensitive = useEslintOrdering ? compareStringsCaseInsensitiveEslintCompatible : compareStringsCaseInsensitive;
+    const caseInsensitiveComparer = getString
+        ? (a: T, b: T) => compareCaseInsensitive(getString(a), getString(b))
+        : compareCaseInsensitive as (a: T | undefined, b: T | undefined) => Comparison;
+    for (let i = 1, len = array.length; i < len; i++) {
+        const prevElement = array[i - 1];
+        const element = array[i];
+        if (kind & SortKind.CaseSensitive && caseSensitiveComparer(prevElement, element) === Comparison.GreaterThan) {
+            kind &= ~SortKind.CaseSensitive;
+        }
+        if (kind & SortKind.CaseInsensitive && caseInsensitiveComparer(prevElement, element) === Comparison.GreaterThan) {
+            kind &= ~SortKind.CaseInsensitive;
+        }
+        if (kind === SortKind.None) {
+            return kind;
+        }
+    }
+    return kind;
+}
+
 /** @internal */
 export function arrayIsEqualTo<T>(array1: readonly T[] | undefined, array2: readonly T[] | undefined, equalityComparer: (a: T, b: T, index: number) => boolean = equateValues): boolean {
     if (!array1 || !array2) {
@@ -2144,6 +2181,23 @@ export function memoizeOne<A extends string | number | boolean | undefined, T>(c
     };
 }
 
+/**
+ * A version of `memoize` that supports a single non-primitive argument, stored as keys of a WeakMap.
+ *
+ * @internal
+ */
+export function memoizeWeak<A extends object, T>(callback: (arg: A) => T): (arg: A) => T {
+    const map = new WeakMap<A, T>();
+    return (arg: A) => {
+        let value = map.get(arg);
+        if (value === undefined && !map.has(arg)) {
+            value = callback(arg);
+            map.set(arg, value);
+        }
+        return value!;
+    };
+}
+
 /**
  * High-order function, composes functions. Note that functions are composed inside-out;
  * for example, `compose(a, b)` is the equivalent of `x => b(a(x))`.
@@ -2293,6 +2347,27 @@ export function compareStringsCaseInsensitive(a: string, b: string) {
     return a < b ? Comparison.LessThan : a > b ? Comparison.GreaterThan : Comparison.EqualTo;
 }
 
+/**
+ * `compareStringsCaseInsensitive` transforms letters to uppercase for unicode reasons,
+ * while eslint's `sort-imports` rule transforms letters to lowercase. Which one you choose
+ * affects the relative order of letters and ASCII characters 91-96, of which `_` is a
+ * valid character in an identifier. So if we used `compareStringsCaseInsensitive` for
+ * import sorting, TypeScript and eslint would disagree about the correct case-insensitive
+ * sort order for `__String` and `Foo`. Since eslint's whole job is to create consistency
+ * by enforcing nitpicky details like this, it makes way more sense for us to just adopt
+ * their convention so users can have auto-imports without making eslint angry.
+ *
+ * @internal
+ */
+export function compareStringsCaseInsensitiveEslintCompatible(a: string, b: string) {
+    if (a === b) return Comparison.EqualTo;
+    if (a === undefined) return Comparison.LessThan;
+    if (b === undefined) return Comparison.GreaterThan;
+    a = a.toLowerCase();
+    b = b.toLowerCase();
+    return a < b ? Comparison.LessThan : a > b ? Comparison.GreaterThan : Comparison.EqualTo;
+}
+
 /**
  * Compare two strings using a case-sensitive ordinal comparison.
  *

src/compiler/types.ts

@@ -9740,6 +9740,7 @@ export interface UserPreferences {
     readonly includeInlayEnumMemberValueHints?: boolean;
     readonly allowRenameOfImportPath?: boolean;
     readonly autoImportFileExcludePatterns?: string[];
+    readonly organizeImportsIgnoreCase?: "auto" | boolean;
 }
 
 /** Represents a bigint literal value without requiring bigint support */

src/harness/fourslashImpl.ts

@@ -535,8 +535,8 @@ export class TestState {
         }
     }
 
-    public verifyOrganizeImports(newContent: string, mode?: ts.OrganizeImportsMode) {
-        const changes = this.languageService.organizeImports({ fileName: this.activeFile.fileName, type: "file", mode }, this.formatCodeSettings, ts.emptyOptions);
+    public verifyOrganizeImports(newContent: string, mode?: ts.OrganizeImportsMode, preferences?: ts.UserPreferences) {
+        const changes = this.languageService.organizeImports({ fileName: this.activeFile.fileName, type: "file", mode }, this.formatCodeSettings, preferences);
         this.applyChanges(changes);
         this.verifyFileContent(this.activeFile.fileName, newContent);
     }

src/harness/fourslashInterfaceImpl.ts

@@ -630,8 +630,8 @@ export class Verify extends VerifyNegatable {
         this.state.noMoveToNewFile();
     }
 
-    public organizeImports(newContent: string, mode?: ts.OrganizeImportsMode): void {
-        this.state.verifyOrganizeImports(newContent, mode);
+    public organizeImports(newContent: string, mode?: ts.OrganizeImportsMode, preferences?: ts.UserPreferences): void {
+        this.state.verifyOrganizeImports(newContent, mode, preferences);
     }
 }
 

src/server/protocol.ts

@@ -3516,6 +3516,7 @@ export interface UserPreferences {
     readonly includeInlayFunctionLikeReturnTypeHints?: boolean;
     readonly includeInlayEnumMemberValueHints?: boolean;
     readonly autoImportFileExcludePatterns?: string[];
+    readonly organizeImportsIgnoreCase?: "auto" | boolean;
 
     /**
      * Indicates whether {@link ReferencesResponseItem.lineText} is supported.

src/services/codefixes/importFixes.ts

@@ -118,6 +118,7 @@ import {
     skipAlias,
     some,
     sort,
+    SortKind,
     SourceFile,
     stableSort,
     startsWith,
@@ -164,15 +165,14 @@ registerCodeFix({
         const { errorCode, preferences, sourceFile, span, program } = context;
         const info = getFixInfos(context, errorCode, span.start, /*useAutoImportProvider*/ true);
         if (!info) return undefined;
-        const quotePreference = getQuotePreference(sourceFile, preferences);
         return info.map(({ fix, symbolName, errorIdentifierText }) => codeActionForFix(
             context,
             sourceFile,
             symbolName,
             fix,
             /*includeSymbolNameInDescription*/ symbolName !== errorIdentifierText,
-            quotePreference,
-            program.getCompilerOptions()));
+            program.getCompilerOptions(),
+            preferences));
     },
     fixIds: [importFixId],
     getAllCodeActions: context => {
@@ -358,7 +358,8 @@ function createImportAdderWorker(sourceFile: SourceFile, program: Program, useAu
                 importClauseOrBindingPattern,
                 defaultImport,
                 arrayFrom(namedImports.entries(), ([name, addAsTypeOnly]) => ({ addAsTypeOnly, name })),
-                compilerOptions);
+                compilerOptions,
+                preferences);
         });
 
         let newDeclarations: AnyImportOrRequireStatement | readonly AnyImportOrRequireStatement[] | undefined;
@@ -516,7 +517,8 @@ export function getImportCompletionAction(
             symbolName,
             fix,
             /*includeSymbolNameInDescription*/ false,
-            getQuotePreference(sourceFile, preferences), compilerOptions))
+            compilerOptions,
+            preferences))
     };
 }
 
@@ -526,7 +528,7 @@ export function getPromoteTypeOnlyCompletionAction(sourceFile: SourceFile, symbo
     const symbolName = single(getSymbolNamesToImport(sourceFile, program.getTypeChecker(), symbolToken, compilerOptions));
     const fix = getTypeOnlyPromotionFix(sourceFile, symbolToken, symbolName, program);
     const includeSymbolNameInDescription = symbolName !== symbolToken.text;
-    return fix && codeFixActionToCodeAction(codeActionForFix({ host, formatContext, preferences }, sourceFile, symbolName, fix, includeSymbolNameInDescription, QuotePreference.Double, compilerOptions));
+    return fix && codeFixActionToCodeAction(codeActionForFix({ host, formatContext, preferences }, sourceFile, symbolName, fix, includeSymbolNameInDescription, compilerOptions, preferences));
 }
 
 function getImportFixForSymbol(sourceFile: SourceFile, exportInfos: readonly SymbolExportInfo[], moduleSymbol: Symbol, program: Program, useNamespaceInfo: { position: number, symbolName: string } | undefined, isValidTypeOnlyUseSite: boolean, useRequire: boolean, host: LanguageServiceHost, preferences: UserPreferences) {
@@ -1176,14 +1178,15 @@ function getExportEqualsImportKind(importingFile: SourceFile, compilerOptions: C
     return allowSyntheticDefaults ? ImportKind.Default : ImportKind.CommonJS;
 }
 
-function codeActionForFix(context: textChanges.TextChangesContext, sourceFile: SourceFile, symbolName: string, fix: ImportFix, includeSymbolNameInDescription: boolean, quotePreference: QuotePreference, compilerOptions: CompilerOptions): CodeFixAction {
+function codeActionForFix(context: textChanges.TextChangesContext, sourceFile: SourceFile, symbolName: string, fix: ImportFix, includeSymbolNameInDescription: boolean, compilerOptions: CompilerOptions, preferences: UserPreferences): CodeFixAction {
     let diag!: DiagnosticAndArguments;
     const changes = textChanges.ChangeTracker.with(context, tracker => {
-        diag = codeActionForFixWorker(tracker, sourceFile, symbolName, fix, includeSymbolNameInDescription, quotePreference, compilerOptions);
+        diag = codeActionForFixWorker(tracker, sourceFile, symbolName, fix, includeSymbolNameInDescription, compilerOptions, preferences);
     });
     return createCodeFixAction(importFixName, changes, diag, importFixId, Diagnostics.Add_all_missing_imports);
 }
-function codeActionForFixWorker(changes: textChanges.ChangeTracker, sourceFile: SourceFile, symbolName: string, fix: ImportFix, includeSymbolNameInDescription: boolean, quotePreference: QuotePreference, compilerOptions: CompilerOptions): DiagnosticAndArguments {
+function codeActionForFixWorker(changes: textChanges.ChangeTracker, sourceFile: SourceFile, symbolName: string, fix: ImportFix, includeSymbolNameInDescription: boolean, compilerOptions: CompilerOptions, preferences: UserPreferences): DiagnosticAndArguments {
+    const quotePreference = getQuotePreference(sourceFile, preferences);
     switch (fix.kind) {
         case ImportFixKind.UseNamespace:
             addNamespaceQualifier(changes, sourceFile, fix);
@@ -1199,7 +1202,8 @@ function codeActionForFixWorker(changes: textChanges.ChangeTracker, sourceFile:
                 importClauseOrBindingPattern,
                 importKind === ImportKind.Default ? { name: symbolName, addAsTypeOnly } : undefined,
                 importKind === ImportKind.Named ? [{ name: symbolName, addAsTypeOnly }] : emptyArray,
-                compilerOptions);
+                compilerOptions,
+                preferences);
             const moduleSpecifierWithoutQuotes = stripQuotes(moduleSpecifier);
             return includeSymbolNameInDescription
                 ? [Diagnostics.Import_0_from_1, symbolName, moduleSpecifierWithoutQuotes]
@@ -1240,10 +1244,11 @@ function promoteFromTypeOnly(changes: textChanges.ChangeTracker, aliasDeclaratio
     switch (aliasDeclaration.kind) {
         case SyntaxKind.ImportSpecifier:
             if (aliasDeclaration.isTypeOnly) {
-                if (aliasDeclaration.parent.elements.length > 1 && OrganizeImports.importSpecifiersAreSorted(aliasDeclaration.parent.elements)) {
+                const sortKind = OrganizeImports.detectImportSpecifierSorting(aliasDeclaration.parent.elements);
+                if (aliasDeclaration.parent.elements.length > 1 && sortKind) {
                     changes.delete(sourceFile, aliasDeclaration);
                     const newSpecifier = factory.updateImportSpecifier(aliasDeclaration, /*isTypeOnly*/ false, aliasDeclaration.propertyName, aliasDeclaration.name);
-                    const insertionIndex = OrganizeImports.getImportSpecifierInsertionIndex(aliasDeclaration.parent.elements, newSpecifier);
+                    const insertionIndex = OrganizeImports.getImportSpecifierInsertionIndex(aliasDeclaration.parent.elements, newSpecifier, sortKind === SortKind.CaseInsensitive);
                     changes.insertImportSpecifierAtIndex(sourceFile, newSpecifier, aliasDeclaration.parent, insertionIndex);
                 }
                 else {
@@ -1274,7 +1279,7 @@ function promoteFromTypeOnly(changes: textChanges.ChangeTracker, aliasDeclaratio
         if (convertExistingToTypeOnly) {
             const namedImports = tryCast(importClause.namedBindings, isNamedImports);
             if (namedImports && namedImports.elements.length > 1) {
-                if (OrganizeImports.importSpecifiersAreSorted(namedImports.elements) &&
+                if (OrganizeImports.detectImportSpecifierSorting(namedImports.elements) &&
                     aliasDeclaration.kind === SyntaxKind.ImportSpecifier &&
                     namedImports.elements.indexOf(aliasDeclaration) !== 0
                 ) {
@@ -1300,6 +1305,7 @@ function doAddExistingFix(
     defaultImport: Import | undefined,
     namedImports: readonly Import[],
     compilerOptions: CompilerOptions,
+    preferences: UserPreferences,
 ): void {
     if (clause.kind === SyntaxKind.ObjectBindingPattern) {
         if (defaultImport) {
@@ -1327,21 +1333,45 @@ function doAddExistingFix(
     }
 
     if (namedImports.length) {
+        // sort case sensitivity:
+        // - if the user preference is explicit, use that
+        // - otherwise, if there are enough existing import specifiers in this import to detect unambiguously, use that
+        // - otherwise, detect from other imports in the file
+        let ignoreCaseForSorting: boolean | undefined;
+        if (typeof preferences.organizeImportsIgnoreCase === "boolean") {
+            ignoreCaseForSorting = preferences.organizeImportsIgnoreCase;
+        }
+        else if (existingSpecifiers) {
+            const targetImportSorting = OrganizeImports.detectImportSpecifierSorting(existingSpecifiers);
+            if (targetImportSorting !== SortKind.Both) {
+                ignoreCaseForSorting = targetImportSorting === SortKind.CaseInsensitive;
+            }
+        }
+        if (ignoreCaseForSorting === undefined) {
+            ignoreCaseForSorting = OrganizeImports.detectSorting(sourceFile) === SortKind.CaseInsensitive;
+        }
+
         const newSpecifiers = stableSort(
             namedImports.map(namedImport => factory.createImportSpecifier(
                 (!clause.isTypeOnly || promoteFromTypeOnly) && needsTypeOnly(namedImport),
                 /*propertyName*/ undefined,
                 factory.createIdentifier(namedImport.name))),
-            OrganizeImports.compareImportOrExportSpecifiers);
-
-        if (existingSpecifiers?.length && OrganizeImports.importSpecifiersAreSorted(existingSpecifiers)) {
+            (s1, s2) => OrganizeImports.compareImportOrExportSpecifiers(s1, s2, ignoreCaseForSorting));
+
+        // The sorting preference computed earlier may or may not have validated that these particular
+        // import specifiers are sorted. If they aren't, `getImportSpecifierInsertionIndex` will return
+        // nonsense. So if there are existing specifiers, even if we know the sorting preference, we
+        // need to ensure that the existing specifiers are sorted according to the preference in order
+        // to do a sorted insertion.
+        const specifierSort = existingSpecifiers?.length && OrganizeImports.detectImportSpecifierSorting(existingSpecifiers);
+        if (specifierSort && !(ignoreCaseForSorting && specifierSort === SortKind.CaseSensitive)) {
             for (const spec of newSpecifiers) {
                 // Organize imports puts type-only import specifiers last, so if we're
                 // adding a non-type-only specifier and converting all the other ones to
                 // type-only, there's no need to ask for the insertion index - it's 0.
                 const insertionIndex = convertExistingToTypeOnly && !spec.isTypeOnly
                     ? 0
-                    : OrganizeImports.getImportSpecifierInsertionIndex(existingSpecifiers, spec);
+                    : OrganizeImports.getImportSpecifierInsertionIndex(existingSpecifiers, spec, ignoreCaseForSorting);
                 changes.insertImportSpecifierAtIndex(sourceFile, spec, clause.namedBindings as NamedImports, insertionIndex);
             }
         }