Fix incorrect suggestion for package that bundles types

src/compiler/checker.ts

@@ -294,16 +294,20 @@ namespace ts {
     }
 
     export function createTypeChecker(host: TypeCheckerHost, produceDiagnostics: boolean): TypeChecker {
-        const getPackagesSet = memoize(() => {
-            const set = new Set<string>();
+        const getPackagesMap = memoize(() => {
+            // A package name maps to true when we detect it has .d.ts files.
+            // This is useful as an approximation of whether a package bundles its own types.
+            // Note: we only look at files already found by module resolution,
+            // so there may be files we did not consider.
+            const map = new Map<string, boolean>();
             host.getSourceFiles().forEach(sf => {
                 if (!sf.resolvedModules) return;
 
                 forEachEntry(sf.resolvedModules, r => {
-                    if (r && r.packageId) set.add(r.packageId.name);
+                    if (r && r.packageId) map.set(r.packageId.name, r.extension === Extension.Dts || !!map.get(r.packageId.name));
                 });
             });
-            return set;
+            return map;
         });
 
         // Cancellation that controls whether or not we can cancel in the middle of type checking.
@@ -3416,11 +3420,17 @@ namespace ts {
                         /*details*/ undefined,
                         Diagnostics.If_the_0_package_actually_exposes_this_module_consider_sending_a_pull_request_to_amend_https_Colon_Slash_Slashgithub_com_SlashDefinitelyTyped_SlashDefinitelyTyped_Slashtree_Slashmaster_Slashtypes_Slash_1,
                         packageId.name, mangleScopedPackageName(packageId.name))
-                    : chainDiagnosticMessages(
-                        /*details*/ undefined,
-                        Diagnostics.Try_npm_i_save_dev_types_Slash_1_if_it_exists_or_add_a_new_declaration_d_ts_file_containing_declare_module_0,
-                        moduleReference,
-                        mangleScopedPackageName(packageId.name))
+                    : packageBundlesTypes(packageId.name)
+                        ? chainDiagnosticMessages(
+                            /*details*/ undefined,
+                            Diagnostics.If_the_0_package_actually_exposes_this_module_try_adding_a_new_declaration_d_ts_file_containing_declare_module_1,
+                            packageId.name,
+                            moduleReference)
+                        : chainDiagnosticMessages(
+                            /*details*/ undefined,
+                            Diagnostics.Try_npm_i_save_dev_types_Slash_1_if_it_exists_or_add_a_new_declaration_d_ts_file_containing_declare_module_0,
+                            moduleReference,
+                            mangleScopedPackageName(packageId.name))
                 : undefined;
             errorOrSuggestion(isError, errorNode, chainDiagnosticMessages(
                 errorInfo,
@@ -3429,7 +3439,10 @@ namespace ts {
                 resolvedFileName));
         }
         function typesPackageExists(packageName: string): boolean {
-            return getPackagesSet().has(getTypesPackageName(packageName));
+            return getPackagesMap().has(getTypesPackageName(packageName));
+        }
+        function packageBundlesTypes(packageName: string): boolean {
+            return !!getPackagesMap().get(packageName);
         }
 
         function resolveExternalModuleSymbol(moduleSymbol: Symbol, dontResolveAlias?: boolean): Symbol;

src/compiler/diagnosticMessages.json

@@ -6027,6 +6027,11 @@
         "category": "Error",
         "code": 7057
     },
+    "If the '{0}' package actually exposes this module, try adding a new declaration (.d.ts) file containing `declare module '{1}';`": {
+        "category": "Error",
+        "code": 7058
+    },
+
 
     "You cannot rename this element.": {
         "category": "Error",

tests/baselines/reference/declarationNotFoundPackageBundlesTypes.errors.txt

@@ -0,0 +1,27 @@
+tests/cases/conformance/moduleResolution/index.ts(2,24): error TS7016: Could not find a declaration file for module 'foo/other'. 'tests/cases/conformance/moduleResolution/node_modules/foo/other.js' implicitly has an 'any' type.
+  If the 'foo' package actually exposes this module, try adding a new declaration (.d.ts) file containing `declare module 'foo/other';`
+
+
+==== tests/cases/conformance/moduleResolution/index.ts (1 errors) ====
+    import * as Foo from "foo";
+    import * as Other from "foo/other"/*1*/;
+                           ~~~~~~~~~~~
+!!! error TS7016: Could not find a declaration file for module 'foo/other'. 'tests/cases/conformance/moduleResolution/node_modules/foo/other.js' implicitly has an 'any' type.
+!!! error TS7016:   If the 'foo' package actually exposes this module, try adding a new declaration (.d.ts) file containing `declare module 'foo/other';`
+==== tests/cases/conformance/moduleResolution/node_modules/foo/package.json (0 errors) ====
+    {   
+        "name": "foo",
+        "version": "1.0.0"
+    }
+
+==== tests/cases/conformance/moduleResolution/node_modules/foo/index.js (0 errors) ====
+    var foo = 0;
+    module.exports = foo;
+
+==== tests/cases/conformance/moduleResolution/node_modules/foo/index.d.ts (0 errors) ====
+    declare const foo: any;
+    export = foo;
+
+==== tests/cases/conformance/moduleResolution/node_modules/foo/other.js (0 errors) ====
+    module.exports = {};
+

tests/baselines/reference/declarationNotFoundPackageBundlesTypes.js

@@ -0,0 +1,26 @@
+//// [tests/cases/conformance/moduleResolution/declarationNotFoundPackageBundlesTypes.ts] ////
+
+//// [package.json]
+{   
+    "name": "foo",
+    "version": "1.0.0"
+}
+
+//// [index.js]
+var foo = 0;
+module.exports = foo;
+
+//// [index.d.ts]
+declare const foo: any;
+export = foo;
+
+//// [other.js]
+module.exports = {};
+
+//// [index.ts]
+import * as Foo from "foo";
+import * as Other from "foo/other"/*1*/;
+
+//// [index.js]
+"use strict";
+exports.__esModule = true;

tests/baselines/reference/declarationNotFoundPackageBundlesTypes.symbols

@@ -0,0 +1,14 @@
+=== tests/cases/conformance/moduleResolution/index.ts ===
+import * as Foo from "foo";
+>Foo : Symbol(Foo, Decl(index.ts, 0, 6))
+
+import * as Other from "foo/other"/*1*/;
+>Other : Symbol(Other, Decl(index.ts, 1, 6))
+
+=== tests/cases/conformance/moduleResolution/node_modules/foo/index.d.ts ===
+declare const foo: any;
+>foo : Symbol(foo, Decl(index.d.ts, 0, 13))
+
+export = foo;
+>foo : Symbol(foo, Decl(index.d.ts, 0, 13))
+

tests/baselines/reference/declarationNotFoundPackageBundlesTypes.types

@@ -0,0 +1,14 @@
+=== tests/cases/conformance/moduleResolution/index.ts ===
+import * as Foo from "foo";
+>Foo : any
+
+import * as Other from "foo/other"/*1*/;
+>Other : any
+
+=== tests/cases/conformance/moduleResolution/node_modules/foo/index.d.ts ===
+declare const foo: any;
+>foo : any
+
+export = foo;
+>foo : any
+

tests/cases/conformance/moduleResolution/declarationNotFoundPackageBundlesTypes.ts

@@ -0,0 +1,23 @@
+// @noImplicitAny: true
+// @noImplicitReferences: true
+
+// @filename: node_modules/foo/package.json
+{   
+    "name": "foo",
+    "version": "1.0.0"
+}
+
+// @filename: node_modules/foo/index.js
+var foo = 0;
+module.exports = foo;
+
+// @filename: node_modules/foo/index.d.ts
+declare const foo: any;
+export = foo;
+
+// @filename: node_modules/foo/other.js
+module.exports = {};
+
+// @filename: index.ts
+import * as Foo from "foo";
+import * as Other from "foo/other"/*1*/;