Experiment: use limited impliedNodeFormat for interop checking

Author: andrewbranch

src/compiler/checker.ts

@@ -4058,22 +4058,22 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             || isNamespaceExport(node));
     }
 
-    function getUsageModeForExpression(usage: Expression) {
-        return isStringLiteralLike(usage) ? host.getModeForUsageLocation(getSourceFileOfNode(usage), usage) : undefined;
+    function getEmitSyntaxForModuleSpecifierExpression(usage: Expression) {
+        return isStringLiteralLike(usage) ? host.getEmitSyntaxForUsageLocation(getSourceFileOfNode(usage), usage) : undefined;
     }
 
     function isESMFormatImportImportingCommonjsFormatFile(usageMode: ResolutionMode, targetMode: ResolutionMode) {
         return usageMode === ModuleKind.ESNext && targetMode === ModuleKind.CommonJS;
     }
 
     function isOnlyImportedAsDefault(usage: Expression) {
-        const usageMode = getUsageModeForExpression(usage);
+        const usageMode = getEmitSyntaxForModuleSpecifierExpression(usage);
         return usageMode === ModuleKind.ESNext && endsWith((usage as StringLiteralLike).text, Extension.Json);
     }
 
     function canHaveSyntheticDefault(file: SourceFile | undefined, moduleSymbol: Symbol, dontResolveAlias: boolean, usage: Expression) {
-        const usageMode = file && getUsageModeForExpression(usage);
-        if (file && usageMode !== undefined && ModuleKind.Node16 <= moduleKind && moduleKind <= ModuleKind.NodeNext) {
+        const usageMode = file && getEmitSyntaxForModuleSpecifierExpression(usage);
+        if (file && usageMode !== undefined) {
             const result = isESMFormatImportImportingCommonjsFormatFile(usageMode, impliedNodeFormatForInteropChecking(file, compilerOptions));
             if (usageMode === ModuleKind.ESNext || result) {
                 return result;
@@ -5301,7 +5301,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 }
 
                 const targetFile = moduleSymbol?.declarations?.find(isSourceFile);
-                const isEsmCjsRef = targetFile && isESMFormatImportImportingCommonjsFormatFile(getUsageModeForExpression(reference), impliedNodeFormatForInteropChecking(targetFile, compilerOptions));
+                const isEsmCjsRef = targetFile && isESMFormatImportImportingCommonjsFormatFile(getEmitSyntaxForModuleSpecifierExpression(reference), impliedNodeFormatForInteropChecking(targetFile, compilerOptions));
                 if (getESModuleInterop(compilerOptions) || isEsmCjsRef) {
                     let sigs = getSignaturesOfStructuredType(type, SignatureKind.Call);
                     if (!sigs || !sigs.length) {
@@ -46071,7 +46071,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 return; // Other grammar checks do not apply to type-only imports with resolution mode assertions
             }
 
-            const mode = (moduleKind === ModuleKind.NodeNext) && declaration.moduleSpecifier && getUsageModeForExpression(declaration.moduleSpecifier);
+            const mode = (moduleKind === ModuleKind.NodeNext) && declaration.moduleSpecifier && getEmitSyntaxForModuleSpecifierExpression(declaration.moduleSpecifier);
             if (mode !== ModuleKind.ESNext && moduleKind !== ModuleKind.ESNext && moduleKind !== ModuleKind.Preserve) {
                 const message = isImportAttributes
                     ? moduleKind === ModuleKind.NodeNext

src/compiler/program.ts

@@ -136,6 +136,8 @@ import {
     getPositionOfLineAndCharacter,
     getPropertyArrayElementValue,
     getResolveJsonModule,
+    getResolvePackageJsonExports,
+    getResolvePackageJsonImports,
     getRootLength,
     getSetExternalModuleIndicator,
     getSourceFileOfNode,
@@ -913,23 +915,46 @@ function getModeForUsageLocationWorker(file: { impliedNodeFormat?: ResolutionMod
             return override;
         }
     }
+
+    const emitSyntax = getEmitSyntaxForUsageLocationWorker(file, usage, compilerOptions);
+    const moduleResolution = compilerOptions && getEmitModuleResolutionKind(compilerOptions);
+    if (
+        compilerOptions && (
+            getResolvePackageJsonExports(compilerOptions) ||
+            getResolvePackageJsonImports(compilerOptions) ||
+            ModuleResolutionKind.Node16 <= moduleResolution! && moduleResolution! <= ModuleResolutionKind.NodeNext
+        )
+    ) {
+        return emitSyntax;
+    }
+}
+
+function getEmitSyntaxForUsageLocationWorker(file: { impliedNodeFormat?: ResolutionMode; }, usage: StringLiteralLike, compilerOptions?: CompilerOptions): ResolutionMode {
     if (compilerOptions && getEmitModuleKind(compilerOptions) === ModuleKind.Preserve) {
         return (usage.parent.parent && isImportEqualsDeclaration(usage.parent.parent) || isRequireCall(usage.parent, /*requireStringLiteralLikeArgument*/ false))
             ? ModuleKind.CommonJS
             : ModuleKind.ESNext;
     }
-    if (file.impliedNodeFormat === undefined || !(compilerOptions && impliedNodeFormatAffectsModuleResolution(compilerOptions))) {
-        // TODO: we don't know whether this is being called for module resolution, emit, or interop checking
+    if (!compilerOptions) {
+        // This should always be provided, but we try to fail somewhat
+        // gracefully to allow projects like ts-node time to update.
         return undefined;
     }
-    if (file.impliedNodeFormat !== ModuleKind.ESNext) {
-        // in cjs files, import call expressions are esm format, otherwise everything is cjs
-        return isImportCall(walkUpParenthesizedExpressions(usage.parent)) ? ModuleKind.ESNext : ModuleKind.CommonJS;
+    if (impliedNodeFormatAffectsModuleResolution(compilerOptions)) {
+        if (file.impliedNodeFormat !== ModuleKind.ESNext) {
+            // in cjs files, import call expressions are esm format, otherwise everything is cjs
+            return isImportCall(walkUpParenthesizedExpressions(usage.parent)) ? ModuleKind.ESNext : ModuleKind.CommonJS;
+        }
+        const exprParentParent = walkUpParenthesizedExpressions(usage.parent)?.parent;
+        return exprParentParent && isImportEqualsDeclaration(exprParentParent) ? ModuleKind.CommonJS : ModuleKind.ESNext;
     }
-    // in esm files, import=require statements are cjs format, otherwise everything is esm
-    // imports are only parent'd up to their containing declaration/expression, so access farther parents with care
-    const exprParentParent = walkUpParenthesizedExpressions(usage.parent)?.parent;
-    return exprParentParent && isImportEqualsDeclaration(exprParentParent) ? ModuleKind.CommonJS : ModuleKind.ESNext;
+    if (getEmitModuleKind(compilerOptions) === ModuleKind.CommonJS) {
+        return ModuleKind.CommonJS;
+    }
+    if (emitModuleKindIsNonNodeESM(getEmitModuleKind(compilerOptions))) {
+        return ModuleKind.ESNext;
+    }
+    return undefined;
 }
 
 /** @internal */
@@ -1897,6 +1922,7 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
         isSourceFileFromExternalLibrary,
         isSourceFileDefaultLibrary,
         getModeForUsageLocation,
+        getEmitSyntaxForUsageLocation,
         getModeForResolutionAtIndex,
         getSourceFileFromReference,
         getLibFileFromReference,
@@ -4931,6 +4957,11 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
         return getModeForUsageLocationWorker(file, usage, optionsForFile);
     }
 
+    function getEmitSyntaxForUsageLocation(file: SourceFile, usage: StringLiteralLike): ResolutionMode {
+        const optionsForFile = getRedirectReferenceForResolution(file)?.commandLine.options || options;
+        return getEmitSyntaxForUsageLocationWorker(file, usage, optionsForFile);
+    }
+
     function getModeForResolutionAtIndex(file: SourceFile, index: number): ResolutionMode {
         return getModeForUsageLocation(file, getModuleNameStringLiteralAt(file, index));
     }

src/compiler/types.ts

@@ -4847,6 +4847,7 @@ export interface TypeCheckerHost extends ModuleSpecifierResolutionHost {
     getResolvedTypeReferenceDirectives(): ModeAwareCache<ResolvedTypeReferenceDirectiveWithFailedLookupLocations>;
     getProjectReferenceRedirect(fileName: string): string | undefined;
     isSourceOfProjectReferenceRedirect(fileName: string): boolean;
+    getEmitSyntaxForUsageLocation(file: SourceFile, usage: StringLiteralLike): ResolutionMode;
     getModeForUsageLocation(file: SourceFile, usage: StringLiteralLike): ResolutionMode;
 
     getResolvedModule(f: SourceFile, moduleName: string, mode: ResolutionMode): ResolvedModuleWithFailedLookupLocations | undefined;

src/compiler/utilities.ts

@@ -8610,12 +8610,6 @@ export function impliedNodeFormatAffectsModuleResolution(options: CompilerOption
     return ModuleResolutionKind.Node16 <= moduleResolution && moduleResolution <= ModuleResolutionKind.NodeNext;
 }
 
-/** @internal */
-export function impliedNodeFormatAffectsInteropChecking(options: CompilerOptions) {
-    const moduleKind = getEmitModuleKind(options);
-    return ModuleKind.Node16 <= moduleKind && moduleKind <= ModuleKind.NodeNext;
-}
-
 /** @internal */
 export function impliedNodeFormatForModuleResolution(sourceFile: SourceFile, options: CompilerOptions): ResolutionMode {
     return impliedNodeFormatAffectsModuleResolution(options) ? sourceFile.impliedNodeFormat : undefined;
@@ -8628,7 +8622,25 @@ export function impliedNodeFormatForEmit(sourceFile: SourceFile, options: Compil
 
 /** @internal */
 export function impliedNodeFormatForInteropChecking(sourceFile: SourceFile, options: CompilerOptions): ResolutionMode {
-    return impliedNodeFormatAffectsInteropChecking(options) ? sourceFile.impliedNodeFormat : undefined;
+    const moduleKind = getEmitModuleKind(options);
+    if (ModuleKind.Node16 <= moduleKind && moduleKind <= ModuleKind.NodeNext) {
+        return sourceFile.impliedNodeFormat;
+    }
+    if (
+        sourceFile.impliedNodeFormat === ModuleKind.CommonJS
+        && (sourceFile.packageJsonScope?.contents.packageJsonContent.type === "commonjs"
+            || fileExtensionIsOneOf(sourceFile.fileName, [Extension.Cjs, Extension.Cts]))
+    ) {
+        return ModuleKind.CommonJS;
+    }
+    if (
+        sourceFile.impliedNodeFormat === ModuleKind.ESNext
+        && (sourceFile.packageJsonScope?.contents.packageJsonContent.type === "module"
+            || fileExtensionIsOneOf(sourceFile.fileName, [Extension.Mjs, Extension.Mts]))
+    ) {
+        return ModuleKind.ESNext;
+    }
+    return undefined;
 }
 
 type CompilerOptionKeys = keyof { [K in keyof CompilerOptions as string extends K ? never : K]: any; };

tests/baselines/reference/api/typescript.d.ts

@@ -9875,7 +9875,7 @@ declare namespace ts {
         },
         usage: StringLiteralLike,
         compilerOptions: CompilerOptions,
-    ): ModuleKind.CommonJS | ModuleKind.ESNext | undefined;
+    ): ResolutionMode;
     function getConfigFileParsingDiagnostics(configFileParseResult: ParsedCommandLine): readonly Diagnostic[];
     /**
      * A function for determining if a given file is esm or cjs format, assuming modern node module resolution rules, as configured by the

tests/baselines/reference/bundlerDirectoryModule(moduleresolution=bundler).trace.json

@@ -937,7 +937,8 @@
     "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
     "Directory '/node_modules' does not exist, skipping all lookups in it.",
     "======== Module name '@typescript/lib-es2023/collection' was not resolved. ========",
-<<<<<<< HEAD
+    "File '/.ts/package.json' does not exist according to earlier cached lookups.",
+    "File '/package.json' does not exist according to earlier cached lookups.",
     "======== Resolving module '@typescript/lib-es2023/intl' from '/.src/__lib_node_modules_lookup_lib.es2023.intl.d.ts__.ts'. ========",
     "Explicitly specified module resolution kind: 'Node10'.",
     "Loading module '@typescript/lib-es2023/intl' from 'node_modules' folder, target file types: TypeScript, Declaration.",
@@ -951,10 +952,8 @@
     "Directory '/.src/node_modules' does not exist, skipping all lookups in it.",
     "Directory '/node_modules' does not exist, skipping all lookups in it.",
     "======== Module name '@typescript/lib-es2023/intl' was not resolved. ========",
-=======
     "File '/.ts/package.json' does not exist according to earlier cached lookups.",
     "File '/package.json' does not exist according to earlier cached lookups.",
->>>>>>> a3b9541d66 (Update trace baselines)
     "======== Resolving module '@typescript/lib-esnext/intl' from '/.src/__lib_node_modules_lookup_lib.esnext.intl.d.ts__.ts'. ========",
     "Explicitly specified module resolution kind: 'Node10'.",
     "Loading module '@typescript/lib-esnext/intl' from 'node_modules' folder, target file types: TypeScript, Declaration.",

tests/baselines/reference/bundlerRelative1(module=esnext).errors.txt

@@ -1,5 +1,6 @@
 /main.ts(4,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
 /main.ts(7,16): error TS2307: Cannot find module './redirect/index' or its corresponding type declarations.
+/main.ts(11,8): error TS1192: Module '"/types/cjs"' has no default export.
 
 
 ==== /dir/index.ts (0 errors) ====
@@ -19,7 +20,7 @@
     declare const _: string;
     export = _;
 
-==== /main.ts (2 errors) ====
+==== /main.ts (3 errors) ====
     import { x } from "./dir";
     import {} from "./dir/index";
     import {} from "./dir/index.js";
@@ -35,5 +36,7 @@
     import a from "./types/esm";
     import * as esm from "./types/esm";
     import b from "./types/cjs";
+           ~
+!!! error TS1192: Module '"/types/cjs"' has no default export.
     import * as cjs from "./types/cjs";
 

tests/baselines/reference/bundlerRelative1(module=esnext).types

@@ -44,7 +44,7 @@ import * as esm from "./types/esm";
 >esm : typeof esm
 
 import b from "./types/cjs";
->b : string
+>b : any
 
 import * as cjs from "./types/cjs";
 >cjs : string

tests/baselines/reference/bundlerRelative1(module=preserve).errors.txt

@@ -1,5 +1,6 @@
 /main.ts(4,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
 /main.ts(7,16): error TS2307: Cannot find module './redirect/index' or its corresponding type declarations.
+/main.ts(11,8): error TS1192: Module '"/types/cjs"' has no default export.
 
 
 ==== /dir/index.ts (0 errors) ====
@@ -19,7 +20,7 @@
     declare const _: string;
     export = _;
 
-==== /main.ts (2 errors) ====
+==== /main.ts (3 errors) ====
     import { x } from "./dir";
     import {} from "./dir/index";
     import {} from "./dir/index.js";
@@ -35,5 +36,7 @@
     import a from "./types/esm";
     import * as esm from "./types/esm";
     import b from "./types/cjs";
+           ~
+!!! error TS1192: Module '"/types/cjs"' has no default export.
     import * as cjs from "./types/cjs";
 

tests/baselines/reference/bundlerRelative1(module=preserve).types

@@ -44,7 +44,7 @@ import * as esm from "./types/esm";
 >esm : typeof esm
 
 import b from "./types/cjs";
->b : string
+>b : any
 
 import * as cjs from "./types/cjs";
 >cjs : string

tests/baselines/reference/conditionalExportsResolutionFallback(moduleresolution=bundler).errors.txt

@@ -1,7 +1,6 @@
-error TS5095: Option 'bundler' can only be used when 'module' is set to 'preserve' or to 'es2015' or later.
+/index.ts(1,8): error TS1192: Module '"/node_modules/lodash/index"' has no default export.
 
 
-!!! error TS5095: Option 'bundler' can only be used when 'module' is set to 'preserve' or to 'es2015' or later.
 ==== /node_modules/lodash/package.json (0 errors) ====
     {
         "name": "lodash",
@@ -26,6 +25,8 @@ error TS5095: Option 'bundler' can only be used when 'module' is set to 'preserv
     declare const _: "webpack";
     export = _;
 
-==== /index.ts (0 errors) ====
+==== /index.ts (1 errors) ====
     import _ from "lodash";
+           ~
+!!! error TS1192: Module '"/node_modules/lodash/index"' has no default export.
 

tests/baselines/reference/customConditions(resolvepackagejsonexports=false).errors.txt

@@ -29,5 +29,3 @@ import _ from "lodash";
 
 
 //// [index.js]
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });

tests/baselines/reference/customConditions(resolvepackagejsonexports=false).js

@@ -23,5 +23,5 @@ export = _;
 
 === /index.ts ===
 import _ from "lodash";
->_ : "index"
+>_ : any
 

tests/baselines/reference/customConditions(resolvepackagejsonexports=false).types

@@ -1,7 +1,6 @@
-error TS5095: Option 'bundler' can only be used when 'module' is set to 'preserve' or to 'es2015' or later.
+/index.ts(1,8): error TS1192: Module '"/node_modules/lodash/webpack"' has no default export.
 
 
-!!! error TS5095: Option 'bundler' can only be used when 'module' is set to 'preserve' or to 'es2015' or later.
 ==== /node_modules/lodash/package.json (0 errors) ====
     {
         "name": "lodash",
@@ -26,6 +25,8 @@ error TS5095: Option 'bundler' can only be used when 'module' is set to 'preserv
     declare const _: "webpack";
     export = _;
 
-==== /index.ts (0 errors) ====
+==== /index.ts (1 errors) ====
     import _ from "lodash";
+           ~
+!!! error TS1192: Module '"/node_modules/lodash/webpack"' has no default export.
 

tests/baselines/reference/customConditions(resolvepackagejsonexports=true).errors.txt

@@ -29,5 +29,3 @@ import _ from "lodash";
 
 
 //// [index.js]
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });

tests/baselines/reference/customConditions(resolvepackagejsonexports=true).js

@@ -23,5 +23,5 @@ export = _;
 
 === /index.ts ===
 import _ from "lodash";
->_ : "webpack"
+>_ : any
 

tests/baselines/reference/customConditions(resolvepackagejsonexports=true).types

@@ -0,0 +1,14 @@
+a.ts(1,8): error TS1192: Module '"b"' has no default export.
+
+
+==== a.ts (1 errors) ====
+    import Namespace from "./b";
+           ~~~~~~~~~
+!!! error TS1192: Module '"b"' has no default export.
+    export var x = new Namespace.Foo();
+    
+==== b.d.ts (0 errors) ====
+    export class Foo {
+    	member: string;
+    }
+    

tests/baselines/reference/esModuleInteropEnablesSyntheticDefaultImports.errors.txt

@@ -6,9 +6,7 @@ import Namespace from "./b";
 
 export var x = new Namespace.Foo();
 >x : Symbol(x, Decl(a.ts, 1, 10))
->Namespace.Foo : Symbol(Namespace.Foo, Decl(b.d.ts, 0, 0))
 >Namespace : Symbol(Namespace, Decl(a.ts, 0, 6))
->Foo : Symbol(Namespace.Foo, Decl(b.d.ts, 0, 0))
 
 === b.d.ts ===
 export class Foo {