Fix typedef binding with CJS exports= (#826)

Author: sandersn

internal/checker/checker.go

@@ -5539,7 +5539,7 @@ func (c *Checker) checkExternalModuleExports(node *ast.Node) {
 	links := c.moduleSymbolLinks.Get(moduleSymbol)
 	if !links.exportsChecked {
 		exportEqualsSymbol := moduleSymbol.Exports[ast.InternalSymbolNameExportEquals]
-		if exportEqualsSymbol != nil && c.hasExportedMembers(moduleSymbol) {
+		if exportEqualsSymbol != nil && c.hasExportedMembers(moduleSymbol, exportEqualsSymbol.ValueDeclaration.Kind == ast.KindJSExportAssignment) {
 			declaration := core.OrElse(c.getDeclarationOfAliasSymbol(exportEqualsSymbol), exportEqualsSymbol.ValueDeclaration)
 			if declaration != nil && !isTopLevelInExternalModuleAugmentation(declaration) {
 				c.error(declaration, diagnostics.An_export_assignment_cannot_be_used_in_a_module_with_other_exported_elements)
@@ -5575,10 +5575,17 @@ func (c *Checker) checkExternalModuleExports(node *ast.Node) {
 	}
 }
 
-func (c *Checker) hasExportedMembers(moduleSymbol *ast.Symbol) bool {
+func (c *Checker) hasExportedMembers(moduleSymbol *ast.Symbol, isCommonJS bool) bool {
 	for id := range moduleSymbol.Exports {
 		if id != ast.InternalSymbolNameExportEquals {
-			return true
+			if !isCommonJS {
+				return true
+			}
+			for _, declaration := range moduleSymbol.Exports[id].Declarations {
+				if declaration.Kind != ast.KindJSTypeAliasDeclaration {
+					return true
+				}
+			}
 		}
 	}
 	return false
@@ -15333,13 +15340,27 @@ func (c *Checker) resolveEntityName(name *ast.Node, meaning ast.SymbolFlags, ign
 		if resolveLocation == nil {
 			resolveLocation = name
 		}
-		symbol = c.getMergedSymbol(c.resolveName(resolveLocation, name.Text(), meaning, message, true /*isUse*/, false /*excludeGlobals*/))
+		if meaning == ast.SymbolFlagsNamespace {
+			symbol = c.getMergedSymbol(c.resolveName(resolveLocation, name.Text(), meaning, nil, true /*isUse*/, false /*excludeGlobals*/))
+			if symbol == nil {
+				alias := c.getMergedSymbol(c.resolveName(resolveLocation, name.Text(), ast.SymbolFlagsAlias, nil, true /*isUse*/, false /*excludeGlobals*/))
+				if alias != nil && alias.Name == ast.InternalSymbolNameExportEquals {
+					// resolve typedefs exported from commonjs, stored on the module symbol
+					symbol = alias.Parent
+				}
+			}
+			if symbol == nil && message != nil {
+				c.resolveName(resolveLocation, name.Text(), meaning, message, true /*isUse*/, false /*excludeGlobals*/)
+			}
+		} else {
+			symbol = c.getMergedSymbol(c.resolveName(resolveLocation, name.Text(), meaning, message, true /*isUse*/, false /*excludeGlobals*/))
+		}
 	case ast.KindQualifiedName:
 		qualified := name.AsQualifiedName()
-		symbol = c.resolveQualifiedName(name, qualified.Left, qualified.Right, meaning, ignoreErrors, dontResolveAlias, location)
+		symbol = c.resolveQualifiedName(name, qualified.Left, qualified.Right, meaning, ignoreErrors, location)
 	case ast.KindPropertyAccessExpression:
 		access := name.AsPropertyAccessExpression()
-		symbol = c.resolveQualifiedName(name, access.Expression, access.Name(), meaning, ignoreErrors, dontResolveAlias, location)
+		symbol = c.resolveQualifiedName(name, access.Expression, access.Name(), meaning, ignoreErrors, location)
 	default:
 		panic("Unknown entity name kind")
 	}
@@ -15357,7 +15378,7 @@ func (c *Checker) resolveEntityName(name *ast.Node, meaning ast.SymbolFlags, ign
 	return symbol
 }
 
-func (c *Checker) resolveQualifiedName(name *ast.Node, left *ast.Node, right *ast.Node, meaning ast.SymbolFlags, ignoreErrors bool, dontResolveAlias bool, location *ast.Node) *ast.Symbol {
+func (c *Checker) resolveQualifiedName(name *ast.Node, left *ast.Node, right *ast.Node, meaning ast.SymbolFlags, ignoreErrors bool, location *ast.Node) *ast.Symbol {
 	namespace := c.resolveEntityName(left, ast.SymbolFlagsNamespace, ignoreErrors, false /*dontResolveAlias*/, location)
 	if namespace == nil || ast.NodeIsMissing(right) {
 		return nil
@@ -15713,12 +15734,26 @@ func (c *Checker) getExportsOfModuleWorker(moduleSymbol *ast.Symbol) (exports as
 		}
 		return symbols
 	}
+	var originalModule *ast.Symbol
+	if moduleSymbol != nil {
+		if c.resolveSymbolEx(moduleSymbol.Exports[ast.InternalSymbolNameExportEquals], false /*dontResolveAlias*/) != nil {
+			originalModule = moduleSymbol
+		}
+	}
 	// A module defined by an 'export=' consists of one export that needs to be resolved
 	moduleSymbol = c.resolveExternalModuleSymbol(moduleSymbol, false /*dontResolveAlias*/)
 	exports = visit(moduleSymbol, nil, false)
 	if exports == nil {
 		exports = make(ast.SymbolTable)
 	}
+	// A CommonJS module defined by an 'export=' might also export typedefs, stored on the original module
+	if originalModule != nil && len(originalModule.Exports) > 1 {
+		for _, symbol := range originalModule.Exports {
+			if symbol.Flags&ast.SymbolFlagsType != 0 && symbol.Name != ast.InternalSymbolNameExportEquals && exports[symbol.Name] == nil {
+				exports[symbol.Name] = symbol
+			}
+		}
+	}
 	for name := range nonTypeOnlyNames.Keys() {
 		delete(typeOnlyExportStarMap, name)
 	}
@@ -23972,6 +24007,13 @@ func (c *Checker) getTypeFromImportTypeNode(node *ast.Node) *Type {
 					symbolFromVariable = c.getPropertyOfTypeEx(c.getTypeOfSymbol(mergedResolvedSymbol), current.Text(), false /*skipObjectFunctionPropertyAugment*/, true /*includeTypeOnlyMembers*/)
 				} else {
 					symbolFromModule = c.getSymbol(c.getExportsOfSymbol(mergedResolvedSymbol), current.Text(), meaning)
+					if symbolFromModule == nil {
+						// a CommonJS module might have typedefs exported alongside an export=
+						immediateModuleSymbol := c.resolveExternalModuleSymbol(innerModuleSymbol, true /*dontResolveAlias*/)
+						if immediateModuleSymbol != nil && core.Some(immediateModuleSymbol.Declarations, func(d *ast.Node) bool { return d.Kind == ast.KindJSExportAssignment }) {
+							symbolFromModule = c.getSymbol(c.getExportsOfSymbol(immediateModuleSymbol.Parent), current.Text(), meaning)
+						}
+					}
 				}
 				next := core.OrElse(symbolFromModule, symbolFromVariable)
 				if next == nil {

internal/fourslash/_scripts/failingTests.txt

@@ -326,7 +326,6 @@ TestIndexerReturnTypes1
 TestIndirectClassInstantiation
 TestInstanceTypesForGenericType1
 TestJavascriptModules20
-TestJavascriptModulesTypeImport
 TestJsDocAugments
 TestJsDocAugmentsAndExtends
 TestJsdocCallbackTag

internal/fourslash/tests/gen/javascriptModulesTypeImport_test.go

@@ -10,7 +10,7 @@ import (
 
 func TestJavascriptModulesTypeImport(t *testing.T) {
 	t.Parallel()
-	t.Skip()
+
 	defer testutil.RecoverAndFail(t, "Panic on fourslash test")
 	const content = `// @allowJs: true
 // @Filename: types.js

testdata/baselines/reference/conformance/typedefModuleExportsIndirect1.js

@@ -0,0 +1,64 @@
+//// [tests/cases/conformance/salsa/typedefModuleExportsIndirect1.ts] ////
+
+//// [typedefModuleExportsIndirect1.js]
+/** @typedef {{ a: 1, m: 1 }} C */
+const dummy = 0;
+module.exports = dummy;
+//// [use.js]
+/** @typedef {import('./typedefModuleExportsIndirect1').C} C */
+/** @type {C} */
+var c
+
+
+//// [typedefModuleExportsIndirect1.js]
+"use strict";
+/** @typedef {{ a: 1, m: 1 }} C */
+const dummy = 0;
+module.exports = dummy;
+//// [use.js]
+"use strict";
+/** @typedef {import('./typedefModuleExportsIndirect1').C} C */
+/** @type {C} */
+var c;
+
+
+//// [typedefModuleExportsIndirect1.d.ts]
+export type C = {
+    a: 1;
+    m: 1;
+};
+export = dummy;
+//// [use.d.ts]
+type C = import('./typedefModuleExportsIndirect1').C;
+/** @typedef {import('./typedefModuleExportsIndirect1').C} C */
+/** @type {C} */
+declare var c: C;
+
+
+//// [DtsFileErrors]
+
+
+dist/typedefModuleExportsIndirect1.d.ts(5,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
+dist/typedefModuleExportsIndirect1.d.ts(5,10): error TS2304: Cannot find name 'dummy'.
+dist/use.d.ts(1,52): error TS2694: Namespace 'unknown' has no exported member 'C'.
+
+
+==== dist/typedefModuleExportsIndirect1.d.ts (2 errors) ====
+    export type C = {
+        a: 1;
+        m: 1;
+    };
+    export = dummy;
+    ~~~~~~~~~~~~~~~
+!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
+             ~~~~~
+!!! error TS2304: Cannot find name 'dummy'.
+    
+==== dist/use.d.ts (1 errors) ====
+    type C = import('./typedefModuleExportsIndirect1').C;
+                                                       ~
+!!! error TS2694: Namespace 'unknown' has no exported member 'C'.
+    /** @typedef {import('./typedefModuleExportsIndirect1').C} C */
+    /** @type {C} */
+    declare var c: C;
+    

testdata/baselines/reference/conformance/typedefModuleExportsIndirect1.symbols

@@ -0,0 +1,19 @@
+//// [tests/cases/conformance/salsa/typedefModuleExportsIndirect1.ts] ////
+
+=== typedefModuleExportsIndirect1.js ===
+/** @typedef {{ a: 1, m: 1 }} C */
+const dummy = 0;
+>dummy : Symbol(dummy, Decl(typedefModuleExportsIndirect1.js, 1, 5))
+
+module.exports = dummy;
+>module.exports : Symbol(dummy, Decl(typedefModuleExportsIndirect1.js, 1, 5))
+>module : Symbol("typedefModuleExportsIndirect1", Decl(typedefModuleExportsIndirect1.js, 0, 0))
+>exports : Symbol(dummy, Decl(typedefModuleExportsIndirect1.js, 1, 5))
+>dummy : Symbol(dummy, Decl(typedefModuleExportsIndirect1.js, 1, 5))
+
+=== use.js ===
+/** @typedef {import('./typedefModuleExportsIndirect1').C} C */
+/** @type {C} */
+var c
+>c : Symbol(c, Decl(use.js, 2, 3))
+

testdata/baselines/reference/conformance/typedefModuleExportsIndirect1.types

@@ -0,0 +1,21 @@
+//// [tests/cases/conformance/salsa/typedefModuleExportsIndirect1.ts] ////
+
+=== typedefModuleExportsIndirect1.js ===
+/** @typedef {{ a: 1, m: 1 }} C */
+const dummy = 0;
+>dummy : 0
+>0 : 0
+
+module.exports = dummy;
+>module.exports = dummy : 0
+>module.exports : 0
+>module : { readonly dummy: 0; }
+>exports : 0
+>dummy : 0
+
+=== use.js ===
+/** @typedef {import('./typedefModuleExportsIndirect1').C} C */
+/** @type {C} */
+var c
+>c : import("typedefModuleExportsIndirect1").C
+

testdata/baselines/reference/conformance/typedefModuleExportsIndirect2.js

@@ -0,0 +1,64 @@
+//// [tests/cases/conformance/salsa/typedefModuleExportsIndirect2.ts] ////
+
+//// [typedefModuleExportsIndirect2.js]
+/** @typedef {{ a: 1, m: 1 }} C */
+const f = function() {};
+module.exports = f;
+//// [use.js]
+/** @typedef {import('./typedefModuleExportsIndirect2').C} C */
+/** @type {C} */
+var c
+
+
+//// [typedefModuleExportsIndirect2.js]
+"use strict";
+/** @typedef {{ a: 1, m: 1 }} C */
+const f = function () { };
+module.exports = f;
+//// [use.js]
+"use strict";
+/** @typedef {import('./typedefModuleExportsIndirect2').C} C */
+/** @type {C} */
+var c;
+
+
+//// [typedefModuleExportsIndirect2.d.ts]
+export type C = {
+    a: 1;
+    m: 1;
+};
+export = f;
+//// [use.d.ts]
+type C = import('./typedefModuleExportsIndirect2').C;
+/** @typedef {import('./typedefModuleExportsIndirect2').C} C */
+/** @type {C} */
+declare var c: C;
+
+
+//// [DtsFileErrors]
+
+
+dist/typedefModuleExportsIndirect2.d.ts(5,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
+dist/typedefModuleExportsIndirect2.d.ts(5,10): error TS2304: Cannot find name 'f'.
+dist/use.d.ts(1,52): error TS2694: Namespace 'unknown' has no exported member 'C'.
+
+
+==== dist/typedefModuleExportsIndirect2.d.ts (2 errors) ====
+    export type C = {
+        a: 1;
+        m: 1;
+    };
+    export = f;
+    ~~~~~~~~~~~
+!!! error TS2309: An export assignment cannot be used in a module with other exported elements.
+             ~
+!!! error TS2304: Cannot find name 'f'.
+    
+==== dist/use.d.ts (1 errors) ====
+    type C = import('./typedefModuleExportsIndirect2').C;
+                                                       ~
+!!! error TS2694: Namespace 'unknown' has no exported member 'C'.
+    /** @typedef {import('./typedefModuleExportsIndirect2').C} C */
+    /** @type {C} */
+    declare var c: C;
+    

testdata/baselines/reference/conformance/typedefModuleExportsIndirect2.symbols

@@ -0,0 +1,19 @@
+//// [tests/cases/conformance/salsa/typedefModuleExportsIndirect2.ts] ////
+
+=== typedefModuleExportsIndirect2.js ===
+/** @typedef {{ a: 1, m: 1 }} C */
+const f = function() {};
+>f : Symbol(f, Decl(typedefModuleExportsIndirect2.js, 1, 5))
+
+module.exports = f;
+>module.exports : Symbol(f, Decl(typedefModuleExportsIndirect2.js, 1, 5))
+>module : Symbol("typedefModuleExportsIndirect2", Decl(typedefModuleExportsIndirect2.js, 0, 0))
+>exports : Symbol(f, Decl(typedefModuleExportsIndirect2.js, 1, 5))
+>f : Symbol(f, Decl(typedefModuleExportsIndirect2.js, 1, 5))
+
+=== use.js ===
+/** @typedef {import('./typedefModuleExportsIndirect2').C} C */
+/** @type {C} */
+var c
+>c : Symbol(c, Decl(use.js, 2, 3))
+

testdata/baselines/reference/conformance/typedefModuleExportsIndirect2.types

@@ -0,0 +1,21 @@
+//// [tests/cases/conformance/salsa/typedefModuleExportsIndirect2.ts] ////
+
+=== typedefModuleExportsIndirect2.js ===
+/** @typedef {{ a: 1, m: 1 }} C */
+const f = function() {};
+>f : () => void
+>function() {} : () => void
+
+module.exports = f;
+>module.exports = f : () => void
+>module.exports : () => void
+>module : { readonly f: () => void; }
+>exports : () => void
+>f : () => void
+
+=== use.js ===
+/** @typedef {import('./typedefModuleExportsIndirect2').C} C */
+/** @type {C} */
+var c
+>c : import("typedefModuleExportsIndirect2").C
+