Add a related span for suggested declaration locations in error messages.

Author: DanielRosenwasser

src/compiler/checker.ts

@@ -710,7 +710,7 @@ namespace ts {
             }
         }
 
-        function addRelatedInfo(diagnostic: Diagnostic, ...relatedInformation: DiagnosticRelatedInformation[]) {
+        function addRelatedInfo(diagnostic: Diagnostic, ...relatedInformation: [DiagnosticRelatedInformation, ...DiagnosticRelatedInformation[]]) {
             if (!diagnostic.relatedInformation) {
                 diagnostic.relatedInformation = [];
             }
@@ -1434,11 +1434,18 @@ namespace ts {
                         !checkAndReportErrorForUsingTypeAsNamespace(errorLocation, name, meaning) &&
                         !checkAndReportErrorForUsingTypeAsValue(errorLocation, name, meaning) &&
                         !checkAndReportErrorForUsingNamespaceModuleAsValue(errorLocation, name, meaning)) {
-                        let suggestion: string | undefined;
+                        let suggestion: Symbol | undefined;
                         if (suggestedNameNotFoundMessage && suggestionCount < maximumSuggestionCount) {
-                            suggestion = getSuggestionForNonexistentSymbol(originalLocation, name, meaning);
+                            suggestion = getSuggestedSymbolForNonexistentSymbol(originalLocation, name, meaning);
                             if (suggestion) {
-                                error(errorLocation, suggestedNameNotFoundMessage, diagnosticName(nameArg!), suggestion);
+                                const suggestionName = symbolToString(suggestion);
+                                const diagnostic = error(errorLocation, suggestedNameNotFoundMessage, diagnosticName(nameArg!), suggestionName);
+                                if (suggestion.valueDeclaration) {
+                                    addRelatedInfo(
+                                        diagnostic,
+                                        createDiagnosticForNode(suggestion.valueDeclaration, Diagnostics._0_is_declared_here, suggestionName)
+                                    );
+                                }
                             }
                         }
                         if (!suggestion) {
@@ -1674,7 +1681,7 @@ namespace ts {
 
                 if (diagnosticMessage) {
                     addRelatedInfo(diagnosticMessage,
-                        createDiagnosticForNode(declaration, Diagnostics._0_was_declared_here, declarationName)
+                        createDiagnosticForNode(declaration, Diagnostics._0_is_declared_here, declarationName)
                     );
                 }
             }
@@ -1866,9 +1873,15 @@ namespace ts {
                     if (!symbol) {
                         const moduleName = getFullyQualifiedName(moduleSymbol);
                         const declarationName = declarationNameToString(name);
-                        const suggestion = getSuggestionForNonexistentModule(name, targetSymbol);
+                        const suggestion = getSuggestedSymbolForNonexistentModule(name, targetSymbol);
                         if (suggestion !== undefined) {
-                            error(name, Diagnostics.Module_0_has_no_exported_member_1_Did_you_mean_2, moduleName, declarationName, suggestion);
+                            const suggestionName = symbolToString(suggestion);
+                            const diagnostic = error(name, Diagnostics.Module_0_has_no_exported_member_1_Did_you_mean_2, moduleName, declarationName, suggestionName);
+                            if (suggestion.valueDeclaration) {
+                                addRelatedInfo(diagnostic,
+                                    createDiagnosticForNode(suggestion.valueDeclaration, Diagnostics._0_is_declared_here, suggestionName)
+                                );
+                            }
                         }
                         else {
                             error(name, Diagnostics.Module_0_has_no_exported_member_1, moduleName, declarationName);
@@ -17661,7 +17674,7 @@ namespace ts {
 
             if (diagnosticMessage) {
                 addRelatedInfo(diagnosticMessage,
-                    createDiagnosticForNode(valueDeclaration, Diagnostics._0_was_declared_here, declarationName)
+                    createDiagnosticForNode(valueDeclaration, Diagnostics._0_is_declared_here, declarationName)
                 );
             }
         }
@@ -17711,6 +17724,7 @@ namespace ts {
 
         function reportNonexistentProperty(propNode: Identifier, containingType: Type) {
             let errorInfo: DiagnosticMessageChain | undefined;
+            let relatedInfo: Diagnostic | undefined;
             if (containingType.flags & TypeFlags.Union && !(containingType.flags & TypeFlags.Primitive)) {
                 for (const subtype of (containingType as UnionType).types) {
                     if (!getPropertyOfType(subtype, propNode.escapedText)) {
@@ -17724,30 +17738,34 @@ namespace ts {
                 errorInfo = chainDiagnosticMessages(errorInfo, Diagnostics.Property_0_does_not_exist_on_type_1_Did_you_forget_to_use_await, declarationNameToString(propNode), typeToString(containingType));
             }
             else {
-                const suggestion = getSuggestionForNonexistentProperty(propNode, containingType);
+                const suggestion = getSuggestedSymbolForNonexistentProperty(propNode, containingType);
                 if (suggestion !== undefined) {
-                    errorInfo = chainDiagnosticMessages(errorInfo, Diagnostics.Property_0_does_not_exist_on_type_1_Did_you_mean_2, declarationNameToString(propNode), typeToString(containingType), suggestion);
+                    const suggestedName = symbolName(suggestion);
+                    errorInfo = chainDiagnosticMessages(errorInfo, Diagnostics.Property_0_does_not_exist_on_type_1_Did_you_mean_2, declarationNameToString(propNode), typeToString(containingType), suggestedName);
+                    relatedInfo = suggestion.valueDeclaration && createDiagnosticForNode(suggestion.valueDeclaration, Diagnostics._0_is_declared_here, suggestedName);
                 }
                 else {
-                    const suggestion = getSuggestionForNonexistentProperty(propNode, containingType);
-                    if (suggestion !== undefined) {
-                        errorInfo = chainDiagnosticMessages(errorInfo, Diagnostics.Property_0_does_not_exist_on_type_1_Did_you_mean_2, declarationNameToString(propNode), typeToString(containingType), suggestion);
-                    }
-                    else {
-                        errorInfo = chainDiagnosticMessages(errorInfo, Diagnostics.Property_0_does_not_exist_on_type_1, declarationNameToString(propNode), typeToString(containingType));
-                    }
+                    errorInfo = chainDiagnosticMessages(errorInfo, Diagnostics.Property_0_does_not_exist_on_type_1, declarationNameToString(propNode), typeToString(containingType));
                 }
             }
 
-            diagnostics.add(createDiagnosticForNodeFromMessageChain(propNode, errorInfo));
+            const resultDiagnostic = createDiagnosticForNodeFromMessageChain(propNode, errorInfo);
+            if (relatedInfo) {
+                addRelatedInfo(resultDiagnostic, relatedInfo);
+            }
+            diagnostics.add(resultDiagnostic);
+        }
+
+        function getSuggestedSymbolForNonexistentProperty(name: Identifier | string, containingType: Type): Symbol | undefined {
+            return getSpellingSuggestionForName(isString(name) ? name : idText(name), getPropertiesOfType(containingType), SymbolFlags.Value);
         }
 
         function getSuggestionForNonexistentProperty(name: Identifier | string, containingType: Type): string | undefined {
-            const suggestion = getSpellingSuggestionForName(isString(name) ? name : idText(name), getPropertiesOfType(containingType), SymbolFlags.Value);
+            const suggestion = getSuggestedSymbolForNonexistentProperty(name, containingType);
             return suggestion && symbolName(suggestion);
         }
 
-        function getSuggestionForNonexistentSymbol(location: Node | undefined, outerName: __String, meaning: SymbolFlags): string | undefined {
+        function getSuggestedSymbolForNonexistentSymbol(location: Node | undefined, outerName: __String, meaning: SymbolFlags): Symbol | undefined {
             Debug.assert(outerName !== undefined, "outername should always be defined");
             const result = resolveNameHelper(location, outerName, meaning, /*nameNotFoundMessage*/ undefined, outerName, /*isUse*/ false, /*excludeGlobals*/ false, (symbols, name, meaning) => {
                 Debug.assertEqual(outerName, name, "name should equal outerName");
@@ -17757,11 +17775,20 @@ namespace ts {
                 // However, resolveNameHelper will continue and call this callback again, so we'll eventually get a correct suggestion.
                 return symbol || getSpellingSuggestionForName(unescapeLeadingUnderscores(name), arrayFrom(symbols.values()), meaning);
             });
-            return result && symbolName(result);
+            return result;
+        }
+
+        function getSuggestionForNonexistentSymbol(location: Node | undefined, outerName: __String, meaning: SymbolFlags): string | undefined {
+            const symbolResult = getSuggestedSymbolForNonexistentSymbol(location, outerName, meaning);
+            return symbolResult && symbolName(symbolResult)
+        }
+
+        function getSuggestedSymbolForNonexistentModule(name: Identifier, targetModule: Symbol): Symbol | undefined {
+            return targetModule.exports && getSpellingSuggestionForName(idText(name), getExportsOfModuleAsArray(targetModule), SymbolFlags.ModuleMember);
         }
 
         function getSuggestionForNonexistentModule(name: Identifier, targetModule: Symbol): string | undefined {
-            const suggestion = targetModule.exports && getSpellingSuggestionForName(idText(name), getExportsOfModuleAsArray(targetModule), SymbolFlags.ModuleMember);
+            const suggestion = getSuggestedSymbolForNonexistentModule(name, targetModule);
             return suggestion && symbolName(suggestion);
         }
 

src/compiler/diagnosticMessages.json

@@ -2401,7 +2401,7 @@
         "category": "Error",
         "code": 2727
     },
-    "'{0}' was declared here.": {
+    "'{0}' is declared here.": {
         "category": "Error",
         "code": 2728
     },