From 3c130d1317f588fb9a67f473f0e15fba931f4e99 Mon Sep 17 00:00:00 2001
From: Alexander T <alexander.tarasyuk@outlook.com>
Date: Fri, 27 Mar 2020 23:33:01 +0200
Subject: [PATCH] feat(37092): improve error message about missing default
 export (#37212)

---
 src/compiler/checker.ts                       | 37 +++++++++++++------
 src/compiler/diagnosticMessages.json          |  4 ++
 .../reference/exportStar-amd.errors.txt       |  1 +
 .../baselines/reference/exportStar.errors.txt |  1 +
 4 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index e0672300f1cd4..e0d8d8ec5b8d6 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -2388,18 +2388,7 @@ namespace ts {
                         ));
                     }
                     else {
-                        if (moduleSymbol.exports && moduleSymbol.exports.has(node.symbol.escapedName)) {
-                            error(
-                                node.name,
-                                Diagnostics.Module_0_has_no_default_export_Did_you_mean_to_use_import_1_from_0_instead,
-                                symbolToString(moduleSymbol),
-                                symbolToString(node.symbol),
-                            );
-                        }
-                        else {
-                            error(node.name, Diagnostics.Module_0_has_no_default_export, symbolToString(moduleSymbol));
-                        }
-
+                        reportNonDefaultExport(moduleSymbol, node);
                     }
                 }
                 else if (hasSyntheticDefault) {
@@ -2413,6 +2402,30 @@ namespace ts {
             }
         }
 
+        function reportNonDefaultExport(moduleSymbol: Symbol, node: ImportClause) {
+            if (moduleSymbol.exports?.has(node.symbol.escapedName)) {
+                error(
+                    node.name,
+                    Diagnostics.Module_0_has_no_default_export_Did_you_mean_to_use_import_1_from_0_instead,
+                    symbolToString(moduleSymbol),
+                    symbolToString(node.symbol),
+                );
+            }
+            else {
+                const diagnostic = error(node.name, Diagnostics.Module_0_has_no_default_export, symbolToString(moduleSymbol));
+                const exportStar = moduleSymbol.exports?.get(InternalSymbolName.ExportStar);
+                if (exportStar) {
+                    const defaultExport = find(exportStar.declarations, decl => !!(
+                        isExportDeclaration(decl) && decl.moduleSpecifier &&
+                            resolveExternalModuleName(decl, decl.moduleSpecifier)?.exports?.has(InternalSymbolName.Default)
+                    ));
+                    if (defaultExport) {
+                        addRelatedInfo(diagnostic, createDiagnosticForNode(defaultExport, Diagnostics.export_Asterisk_does_not_re_export_a_default));
+                    }
+                }
+            }
+        }
+
         function getTargetOfNamespaceImport(node: NamespaceImport, dontResolveAlias: boolean): Symbol | undefined {
             const moduleSpecifier = node.parent.parent.moduleSpecifier;
             const immediate = resolveExternalModuleName(node, moduleSpecifier);
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 195fc43dbb12d..c591e030fe46d 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -611,6 +611,10 @@
         "category": "Error",
         "code": 1194
     },
+    "'export *' does not re-export a default.": {
+        "category": "Error",
+        "code": 1195
+    },
     "Catch clause variable cannot have a type annotation.": {
         "category": "Error",
         "code": 1196
diff --git a/tests/baselines/reference/exportStar-amd.errors.txt b/tests/baselines/reference/exportStar-amd.errors.txt
index a667c90224e93..86a365b6a3bcc 100644
--- a/tests/baselines/reference/exportStar-amd.errors.txt
+++ b/tests/baselines/reference/exportStar-amd.errors.txt
@@ -30,6 +30,7 @@ tests/cases/conformance/es6/modules/t4.ts(3,1): error TS2308: Module "./t1" has
     import hello, { x, y, z, foo } from "./t4";
            ~~~~~
 !!! error TS1192: Module '"tests/cases/conformance/es6/modules/t4"' has no default export.
+!!! related TS1195 tests/cases/conformance/es6/modules/t4.ts:2:1: 'export *' does not re-export a default.
     hello;
     x;
     y;
diff --git a/tests/baselines/reference/exportStar.errors.txt b/tests/baselines/reference/exportStar.errors.txt
index a667c90224e93..86a365b6a3bcc 100644
--- a/tests/baselines/reference/exportStar.errors.txt
+++ b/tests/baselines/reference/exportStar.errors.txt
@@ -30,6 +30,7 @@ tests/cases/conformance/es6/modules/t4.ts(3,1): error TS2308: Module "./t1" has
     import hello, { x, y, z, foo } from "./t4";
            ~~~~~
 !!! error TS1192: Module '"tests/cases/conformance/es6/modules/t4"' has no default export.
+!!! related TS1195 tests/cases/conformance/es6/modules/t4.ts:2:1: 'export *' does not re-export a default.
     hello;
     x;
     y;