Modify synthetic default generation code for dual-mode module resolution

src/compiler/checker.ts

@@ -2629,7 +2629,23 @@ namespace ts {
             return ((isExportAssignment(node) && !node.isExportEquals) || hasSyntacticModifier(node, ModifierFlags.Default) || isExportSpecifier(node));
         }
 
-        function canHaveSyntheticDefault(file: SourceFile | undefined, moduleSymbol: Symbol, dontResolveAlias: boolean) {
+        function getUsageModeForExpression(usage: Expression) {
+            return isStringLiteralLike(usage) ? getModeForUsageLocation(getSourceFileOfNode(usage), usage) : undefined;
+        }
+
+        function isESMFormatImportImportingCommonjsFormatFile(usageMode: SourceFile["impliedNodeFormat"], targetMode: SourceFile["impliedNodeFormat"]) {
+            return usageMode === ModuleKind.ESNext && targetMode === ModuleKind.CommonJS;
+        }
+
+        function canHaveSyntheticDefault(file: SourceFile | undefined, moduleSymbol: Symbol, dontResolveAlias: boolean, usage: Expression) {
+            const usageMode = file && getUsageModeForExpression(usage);
+            if (file && usageMode !== undefined) {
+                const result = isESMFormatImportImportingCommonjsFormatFile(usageMode, file.impliedNodeFormat);
+                if (usageMode === ModuleKind.ESNext || result) {
+                    return result;
+                }
+                // fallthrough on cjs usages so we imply defaults for interop'd imports, too
+            }
             if (!allowSyntheticDefaultImports) {
                 return false;
             }
@@ -2672,7 +2688,7 @@ namespace ts {
                 }
 
                 const file = moduleSymbol.declarations?.find(isSourceFile);
-                const hasSyntheticDefault = canHaveSyntheticDefault(file, moduleSymbol, dontResolveAlias);
+                const hasSyntheticDefault = canHaveSyntheticDefault(file, moduleSymbol, dontResolveAlias, node.parent.moduleSpecifier);
                 if (!exportDefaultSymbol && !hasSyntheticDefault) {
                     if (hasExportAssignmentSymbol(moduleSymbol)) {
                         const compilerOptionName = moduleKind >= ModuleKind.ES2015 ? "allowSyntheticDefaultImports" : "esModuleInterop";
@@ -2824,7 +2840,7 @@ namespace ts {
                     let symbolFromModule = getExportOfModule(targetSymbol, name, specifier, dontResolveAlias);
                     if (symbolFromModule === undefined && name.escapedText === InternalSymbolName.Default) {
                         const file = moduleSymbol.declarations?.find(isSourceFile);
-                        if (canHaveSyntheticDefault(file, moduleSymbol, dontResolveAlias)) {
+                        if (canHaveSyntheticDefault(file, moduleSymbol, dontResolveAlias, moduleSpecifier)) {
                             symbolFromModule = resolveExternalModuleSymbol(moduleSymbol, dontResolveAlias) || resolveSymbol(moduleSymbol, dontResolveAlias);
                         }
                     }
@@ -3587,7 +3603,7 @@ namespace ts {
                             sigs = getSignaturesOfStructuredType(type, SignatureKind.Construct);
                         }
                         if (sigs && sigs.length) {
-                            const moduleType = getTypeWithSyntheticDefaultImportType(type, symbol, moduleSymbol!);
+                            const moduleType = getTypeWithSyntheticDefaultImportType(type, symbol, moduleSymbol!, isImportCall(referenceParent) ? referenceParent.arguments[0] : referenceParent.moduleSpecifier);
                             // Create a new symbol which has the module's type less the call and construct signatures
                             const result = createSymbol(symbol.flags, symbol.escapedName);
                             result.declarations = symbol.declarations ? symbol.declarations.slice() : [];
@@ -30945,18 +30961,18 @@ namespace ts {
             if (moduleSymbol) {
                 const esModuleSymbol = resolveESModuleSymbol(moduleSymbol, specifier, /*dontRecursivelyResolve*/ true, /*suppressUsageError*/ false);
                 if (esModuleSymbol) {
-                    return createPromiseReturnType(node, getTypeWithSyntheticDefaultImportType(getTypeOfSymbol(esModuleSymbol), esModuleSymbol, moduleSymbol));
+                    return createPromiseReturnType(node, getTypeWithSyntheticDefaultImportType(getTypeOfSymbol(esModuleSymbol), esModuleSymbol, moduleSymbol, specifier));
                 }
             }
             return createPromiseReturnType(node, anyType);
         }
 
-        function getTypeWithSyntheticDefaultImportType(type: Type, symbol: Symbol, originalSymbol: Symbol): Type {
+        function getTypeWithSyntheticDefaultImportType(type: Type, symbol: Symbol, originalSymbol: Symbol, moduleSpecifier: Expression): Type {
             if (allowSyntheticDefaultImports && type && !isErrorType(type)) {
                 const synthType = type as SyntheticDefaultModuleType;
                 if (!synthType.syntheticType) {
                     const file = originalSymbol.declarations?.find(isSourceFile);
-                    const hasSyntheticDefault = canHaveSyntheticDefault(file, originalSymbol, /*dontResolveAlias*/ false);
+                    const hasSyntheticDefault = canHaveSyntheticDefault(file, originalSymbol, /*dontResolveAlias*/ false, moduleSpecifier);
                     if (hasSyntheticDefault) {
                         const memberTable = createSymbolTable();
                         const newSymbol = createSymbol(SymbolFlags.Alias, InternalSymbolName.Default);

tests/baselines/reference/nodeModulesAllowJsSynchronousCallErrors(module=node12).types

@@ -23,9 +23,9 @@ export async function f() {
 >"../index.js" : "../index.js"
 
     const mod4 = await import ("./index.js");
->mod4 : typeof mod2
->await import ("./index.js") : typeof mod2
->import ("./index.js") : Promise<typeof mod2>
+>mod4 : { default: typeof mod2; f(): Promise<void>; }
+>await import ("./index.js") : { default: typeof mod2; f(): Promise<void>; }
+>import ("./index.js") : Promise<{ default: typeof mod2; f(): Promise<void>; }>
 >"./index.js" : "./index.js"
 
     h();
@@ -57,9 +57,9 @@ export async function h() {
 >"./index.js" : "./index.js"
 
     const mod4 = await import ("./subfolder/index.js");
->mod4 : typeof mod2
->await import ("./subfolder/index.js") : typeof mod2
->import ("./subfolder/index.js") : Promise<typeof mod2>
+>mod4 : { default: typeof mod2; f(): Promise<void>; }
+>await import ("./subfolder/index.js") : { default: typeof mod2; f(): Promise<void>; }
+>import ("./subfolder/index.js") : Promise<{ default: typeof mod2; f(): Promise<void>; }>
 >"./subfolder/index.js" : "./subfolder/index.js"
 
     f();

tests/baselines/reference/nodeModulesAllowJsSynchronousCallErrors(module=nodenext).types

@@ -23,9 +23,9 @@ export async function f() {
 >"../index.js" : "../index.js"
 
     const mod4 = await import ("./index.js");
->mod4 : typeof mod2
->await import ("./index.js") : typeof mod2
->import ("./index.js") : Promise<typeof mod2>
+>mod4 : { default: typeof mod2; f(): Promise<void>; }
+>await import ("./index.js") : { default: typeof mod2; f(): Promise<void>; }
+>import ("./index.js") : Promise<{ default: typeof mod2; f(): Promise<void>; }>
 >"./index.js" : "./index.js"
 
     h();
@@ -57,9 +57,9 @@ export async function h() {
 >"./index.js" : "./index.js"
 
     const mod4 = await import ("./subfolder/index.js");
->mod4 : typeof mod2
->await import ("./subfolder/index.js") : typeof mod2
->import ("./subfolder/index.js") : Promise<typeof mod2>
+>mod4 : { default: typeof mod2; f(): Promise<void>; }
+>await import ("./subfolder/index.js") : { default: typeof mod2; f(): Promise<void>; }
+>import ("./subfolder/index.js") : Promise<{ default: typeof mod2; f(): Promise<void>; }>
 >"./subfolder/index.js" : "./subfolder/index.js"
 
     f();

tests/baselines/reference/nodeModulesCjsFormatFileAlwaysHasDefault(module=node12).js

@@ -0,0 +1,36 @@
+//// [tests/cases/conformance/node/nodeModulesCjsFormatFileAlwaysHasDefault.ts] ////
+
+//// [index.ts]
+// cjs format file
+export const a = 1;
+//// [index.ts]
+// esm format file
+import mod from "./subfolder/index.js";
+mod;
+//// [package.json]
+{
+    "name": "package",
+    "private": true,
+    "type": "module"
+}
+//// [package.json]
+{
+    "type": "commonjs"
+}
+
+//// [index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.a = void 0;
+// cjs format file
+exports.a = 1;
+//// [index.js]
+// esm format file
+import mod from "./subfolder/index.js";
+mod;
+
+
+//// [index.d.ts]
+export declare const a = 1;
+//// [index.d.ts]
+export {};

tests/baselines/reference/nodeModulesCjsFormatFileAlwaysHasDefault(module=node12).symbols

@@ -0,0 +1,13 @@
+=== tests/cases/conformance/node/subfolder/index.ts ===
+// cjs format file
+export const a = 1;
+>a : Symbol(a, Decl(index.ts, 1, 12))
+
+=== tests/cases/conformance/node/index.ts ===
+// esm format file
+import mod from "./subfolder/index.js";
+>mod : Symbol(mod, Decl(index.ts, 1, 6))
+
+mod;
+>mod : Symbol(mod, Decl(index.ts, 1, 6))
+

tests/baselines/reference/nodeModulesCjsFormatFileAlwaysHasDefault(module=node12).types

@@ -0,0 +1,14 @@
+=== tests/cases/conformance/node/subfolder/index.ts ===
+// cjs format file
+export const a = 1;
+>a : 1
+>1 : 1
+
+=== tests/cases/conformance/node/index.ts ===
+// esm format file
+import mod from "./subfolder/index.js";
+>mod : typeof mod
+
+mod;
+>mod : typeof mod
+

tests/baselines/reference/nodeModulesCjsFormatFileAlwaysHasDefault(module=nodenext).js

@@ -0,0 +1,36 @@
+//// [tests/cases/conformance/node/nodeModulesCjsFormatFileAlwaysHasDefault.ts] ////
+
+//// [index.ts]
+// cjs format file
+export const a = 1;
+//// [index.ts]
+// esm format file
+import mod from "./subfolder/index.js";
+mod;
+//// [package.json]
+{
+    "name": "package",
+    "private": true,
+    "type": "module"
+}
+//// [package.json]
+{
+    "type": "commonjs"
+}
+
+//// [index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.a = void 0;
+// cjs format file
+exports.a = 1;
+//// [index.js]
+// esm format file
+import mod from "./subfolder/index.js";
+mod;
+
+
+//// [index.d.ts]
+export declare const a = 1;
+//// [index.d.ts]
+export {};

tests/baselines/reference/nodeModulesCjsFormatFileAlwaysHasDefault(module=nodenext).symbols

@@ -0,0 +1,13 @@
+=== tests/cases/conformance/node/subfolder/index.ts ===
+// cjs format file
+export const a = 1;
+>a : Symbol(a, Decl(index.ts, 1, 12))
+
+=== tests/cases/conformance/node/index.ts ===
+// esm format file
+import mod from "./subfolder/index.js";
+>mod : Symbol(mod, Decl(index.ts, 1, 6))
+
+mod;
+>mod : Symbol(mod, Decl(index.ts, 1, 6))
+

tests/baselines/reference/nodeModulesCjsFormatFileAlwaysHasDefault(module=nodenext).types

@@ -0,0 +1,14 @@
+=== tests/cases/conformance/node/subfolder/index.ts ===
+// cjs format file
+export const a = 1;
+>a : 1
+>1 : 1
+
+=== tests/cases/conformance/node/index.ts ===
+// esm format file
+import mod from "./subfolder/index.js";
+>mod : typeof mod
+
+mod;
+>mod : typeof mod
+

tests/baselines/reference/nodeModulesDeclarationEmitDynamicImportWithPackageExports.js

@@ -122,7 +122,9 @@ export {};
 //// [index.d.cts]
 export {};
 //// [other.d.ts]
-export declare const a: typeof import("package/cjs");
+export declare const a: {
+    default: typeof import("package/cjs");
+};
 export declare const b: typeof import("package/mjs");
 export declare const c: typeof import("package");
 export declare const f: {
@@ -134,12 +136,11 @@ export declare const d: {
     default: typeof import("inner/cjs");
     cjsNonmain: true;
 };
-export declare const e: {
-    default: typeof import("inner/mjs");
-    esm: true;
-};
+export declare const e: typeof import("inner/mjs");
 //// [other.d.mts]
-export declare const a: typeof import("package/cjs");
+export declare const a: {
+    default: typeof import("package/cjs");
+};
 export declare const b: typeof import("package/mjs");
 export declare const c: typeof import("package");
 export declare const f: {
@@ -151,12 +152,11 @@ export declare const d: {
     default: typeof import("inner/cjs");
     cjsNonmain: true;
 };
-export declare const e: {
-    default: typeof import("inner/mjs");
-    esm: true;
-};
+export declare const e: typeof import("inner/mjs");
 //// [other.d.cts]
-export declare const a: Promise<typeof import("package/cjs")>;
+export declare const a: Promise<{
+    default: typeof import("package/cjs");
+}>;
 export declare const b: Promise<typeof import("package/mjs")>;
 export declare const c: Promise<typeof import("package")>;
 export declare const f: Promise<{
@@ -168,18 +168,15 @@ export declare const d: Promise<{
     default: typeof import("inner/cjs");
     cjsNonmain: true;
 }>;
-export declare const e: Promise<{
-    default: typeof import("inner/mjs");
-    esm: true;
-}>;
+export declare const e: Promise<typeof import("inner/mjs")>;
 
 
 //// [DtsFileErrors]
 
 
-tests/cases/conformance/node/other.d.cts(2,47): error TS1471: Module 'package/mjs' cannot be imported using this construct. The specifier only resolves to an ES module, which cannot be imported synchronously. Use dynamic import instead.
-tests/cases/conformance/node/other.d.cts(3,47): error TS1471: Module 'package' cannot be imported using this construct. The specifier only resolves to an ES module, which cannot be imported synchronously. Use dynamic import instead.
-tests/cases/conformance/node/other2.d.cts(6,28): error TS1471: Module 'inner/mjs' cannot be imported using this construct. The specifier only resolves to an ES module, which cannot be imported synchronously. Use dynamic import instead.
+tests/cases/conformance/node/other.d.cts(4,47): error TS1471: Module 'package/mjs' cannot be imported using this construct. The specifier only resolves to an ES module, which cannot be imported synchronously. Use dynamic import instead.
+tests/cases/conformance/node/other.d.cts(5,47): error TS1471: Module 'package' cannot be imported using this construct. The specifier only resolves to an ES module, which cannot be imported synchronously. Use dynamic import instead.
+tests/cases/conformance/node/other2.d.cts(5,47): error TS1471: Module 'inner/mjs' cannot be imported using this construct. The specifier only resolves to an ES module, which cannot be imported synchronously. Use dynamic import instead.
 
 
 ==== tests/cases/conformance/node/index.d.ts (0 errors) ====
@@ -192,7 +189,9 @@ tests/cases/conformance/node/other2.d.cts(6,28): error TS1471: Module 'inner/mjs
     export {};
 
 ==== tests/cases/conformance/node/other.d.ts (0 errors) ====
-    export declare const a: typeof import("package/cjs");
+    export declare const a: {
+        default: typeof import("package/cjs");
+    };
     export declare const b: typeof import("package/mjs");
     export declare const c: typeof import("package");
     export declare const f: {
@@ -205,13 +204,12 @@ tests/cases/conformance/node/other2.d.cts(6,28): error TS1471: Module 'inner/mjs
         default: typeof import("inner/cjs");
         cjsNonmain: true;
     };
-    export declare const e: {
-        default: typeof import("inner/mjs");
-        esm: true;
-    };
+    export declare const e: typeof import("inner/mjs");
 
 ==== tests/cases/conformance/node/other.d.mts (0 errors) ====
-    export declare const a: typeof import("package/cjs");
+    export declare const a: {
+        default: typeof import("package/cjs");
+    };
     export declare const b: typeof import("package/mjs");
     export declare const c: typeof import("package");
     export declare const f: {
@@ -224,13 +222,12 @@ tests/cases/conformance/node/other2.d.cts(6,28): error TS1471: Module 'inner/mjs
         default: typeof import("inner/cjs");
         cjsNonmain: true;
     };
-    export declare const e: {
-        default: typeof import("inner/mjs");
-        esm: true;
-    };
+    export declare const e: typeof import("inner/mjs");
 
 ==== tests/cases/conformance/node/other.d.cts (2 errors) ====
-    export declare const a: Promise<typeof import("package/cjs")>;
+    export declare const a: Promise<{
+        default: typeof import("package/cjs");
+    }>;
     export declare const b: Promise<typeof import("package/mjs")>;
                                                   ~~~~~~~~~~~~~
 !!! error TS1471: Module 'package/mjs' cannot be imported using this construct. The specifier only resolves to an ES module, which cannot be imported synchronously. Use dynamic import instead.
@@ -247,12 +244,9 @@ tests/cases/conformance/node/other2.d.cts(6,28): error TS1471: Module 'inner/mjs
         default: typeof import("inner/cjs");
         cjsNonmain: true;
     }>;
-    export declare const e: Promise<{
-        default: typeof import("inner/mjs");
-                               ~~~~~~~~~~~
+    export declare const e: Promise<typeof import("inner/mjs")>;
+                                                  ~~~~~~~~~~~
 !!! error TS1471: Module 'inner/mjs' cannot be imported using this construct. The specifier only resolves to an ES module, which cannot be imported synchronously. Use dynamic import instead.
-        esm: true;
-    }>;
 
 ==== tests/cases/conformance/node/node_modules/inner/index.d.ts (0 errors) ====
     // cjs format file