Add auto-import for the package.json imports field

src/compiler/checker.ts

@@ -50764,7 +50764,7 @@ export function signatureHasLiteralTypes(s: Signature) {
     return !!(s.flags & SignatureFlags.HasLiteralTypes);
 }
 
-function createBasicNodeBuilderModuleSpecifierResolutionHost(host: TypeCheckerHost): ModuleSpecifierResolutionHost & { getCommonSourceDirectory(): string; } {
+function createBasicNodeBuilderModuleSpecifierResolutionHost(host: TypeCheckerHost): ModuleSpecifierResolutionHost {
     return {
         getCommonSourceDirectory: !!(host as Program).getCommonSourceDirectory ? () => (host as Program).getCommonSourceDirectory() : () => "",
         getCurrentDirectory: () => host.getCurrentDirectory(),

src/compiler/core.ts

@@ -2400,9 +2400,13 @@ function levenshteinWithMax(s1: string, s2: string, max: number): number | undef
 }
 
 /** @internal */
-export function endsWith(str: string, suffix: string): boolean {
+export function endsWith(str: string, suffix: string, ignoreCase?: boolean): boolean {
     const expectedPos = str.length - suffix.length;
-    return expectedPos >= 0 && str.indexOf(suffix, expectedPos) === expectedPos;
+    return expectedPos >= 0 && (
+        ignoreCase
+            ? equateStringsCaseInsensitive(str.slice(expectedPos), suffix)
+            : str.indexOf(suffix, expectedPos) === expectedPos
+    );
 }
 
 /** @internal */
@@ -2579,8 +2583,10 @@ export function findBestPatternMatch<T>(values: readonly T[], getPattern: (value
 }
 
 /** @internal */
-export function startsWith(str: string, prefix: string): boolean {
-    return str.lastIndexOf(prefix, 0) === 0;
+export function startsWith(str: string, prefix: string, ignoreCase?: boolean): boolean {
+    return ignoreCase
+        ? equateStringsCaseInsensitive(str.slice(0, prefix.length), prefix)
+        : str.lastIndexOf(prefix, 0) === 0;
 }
 
 /** @internal */

src/compiler/emitter.ts

@@ -583,35 +583,50 @@ export function getOutputExtension(fileName: string, options: CompilerOptions):
         Extension.Js;
 }
 
-function getOutputPathWithoutChangingExt(inputFileName: string, configFile: ParsedCommandLine, ignoreCase: boolean, outputDir: string | undefined, getCommonSourceDirectory?: () => string) {
+function getOutputPathWithoutChangingExt(
+    inputFileName: string,
+    ignoreCase: boolean,
+    outputDir: string | undefined,
+    getCommonSourceDirectory: () => string,
+): string {
     return outputDir ?
         resolvePath(
             outputDir,
-            getRelativePathFromDirectory(getCommonSourceDirectory ? getCommonSourceDirectory() : getCommonSourceDirectoryOfConfig(configFile, ignoreCase), inputFileName, ignoreCase),
+            getRelativePathFromDirectory(getCommonSourceDirectory(), inputFileName, ignoreCase),
         ) :
         inputFileName;
 }
 
 /** @internal */
-export function getOutputDeclarationFileName(inputFileName: string, configFile: ParsedCommandLine, ignoreCase: boolean, getCommonSourceDirectory?: () => string) {
+export function getOutputDeclarationFileName(inputFileName: string, configFile: ParsedCommandLine, ignoreCase: boolean, getCommonSourceDirectory = () => getCommonSourceDirectoryOfConfig(configFile, ignoreCase)) {
+    return getOutputDeclarationFileNameWorker(inputFileName, configFile.options, ignoreCase, getCommonSourceDirectory);
+}
+
+/** @internal */
+export function getOutputDeclarationFileNameWorker(inputFileName: string, options: CompilerOptions, ignoreCase: boolean, getCommonSourceDirectory: () => string) {
     return changeExtension(
-        getOutputPathWithoutChangingExt(inputFileName, configFile, ignoreCase, configFile.options.declarationDir || configFile.options.outDir, getCommonSourceDirectory),
+        getOutputPathWithoutChangingExt(inputFileName, ignoreCase, options.declarationDir || options.outDir, getCommonSourceDirectory),
         getDeclarationEmitExtensionForPath(inputFileName),
     );
 }
 
-function getOutputJSFileName(inputFileName: string, configFile: ParsedCommandLine, ignoreCase: boolean, getCommonSourceDirectory?: () => string) {
+function getOutputJSFileName(inputFileName: string, configFile: ParsedCommandLine, ignoreCase: boolean, getCommonSourceDirectory = () => getCommonSourceDirectoryOfConfig(configFile, ignoreCase)) {
     if (configFile.options.emitDeclarationOnly) return undefined;
     const isJsonFile = fileExtensionIs(inputFileName, Extension.Json);
-    const outputFileName = changeExtension(
-        getOutputPathWithoutChangingExt(inputFileName, configFile, ignoreCase, configFile.options.outDir, getCommonSourceDirectory),
-        getOutputExtension(inputFileName, configFile.options),
-    );
+    const outputFileName = getOutputJSFileNameWorker(inputFileName, configFile.options, ignoreCase, getCommonSourceDirectory);
     return !isJsonFile || comparePaths(inputFileName, outputFileName, Debug.checkDefined(configFile.options.configFilePath), ignoreCase) !== Comparison.EqualTo ?
         outputFileName :
         undefined;
 }
 
+/** @internal */
+export function getOutputJSFileNameWorker(inputFileName: string, options: CompilerOptions, ignoreCase: boolean, getCommonSourceDirectory: () => string): string {
+    return changeExtension(
+        getOutputPathWithoutChangingExt(inputFileName, ignoreCase, options.outDir, getCommonSourceDirectory),
+        getOutputExtension(inputFileName, options),
+    );
+}
+
 function createAddOutput() {
     let outputs: string[] | undefined;
     return { addOutput, getOutputs };

src/compiler/moduleNameResolver.ts

@@ -915,6 +915,11 @@ export function isPackageJsonInfo(entry: PackageJsonInfoCacheEntry | undefined):
     return !!(entry as PackageJsonInfo | undefined)?.contents;
 }
 
+/** @internal */
+export function isMissingPackageJsonInfo(entry: PackageJsonInfoCacheEntry | undefined): entry is MissingPackageJsonInfo {
+    return !!entry && !(entry as PackageJsonInfo).contents;
+}
+
 export interface PackageJsonInfoCache {
     /** @internal */ getPackageJsonInfo(packageJsonPath: string): PackageJsonInfoCacheEntry | undefined;
     /** @internal */ setPackageJsonInfo(packageJsonPath: string, info: PackageJsonInfoCacheEntry): void;