Improve @template lookup and resilience

src/compiler/checker.ts

@@ -9185,7 +9185,6 @@ namespace ts {
                     return undefined;
                 }
                 switch (node.kind) {
-                    case SyntaxKind.VariableStatement:
                     case SyntaxKind.ClassDeclaration:
                     case SyntaxKind.ClassExpression:
                     case SyntaxKind.InterfaceDeclaration:
@@ -9205,28 +9204,32 @@ namespace ts {
                     case SyntaxKind.JSDocEnumTag:
                     case SyntaxKind.JSDocCallbackTag:
                     case SyntaxKind.MappedType:
-                    case SyntaxKind.ConditionalType:
+                    case SyntaxKind.ConditionalType: {
                         const outerTypeParameters = getOuterTypeParameters(node, includeThisTypes);
                         if (node.kind === SyntaxKind.MappedType) {
                             return append(outerTypeParameters, getDeclaredTypeOfTypeParameter(getSymbolOfNode((<MappedTypeNode>node).typeParameter)));
                         }
                         else if (node.kind === SyntaxKind.ConditionalType) {
                             return concatenate(outerTypeParameters, getInferTypeParameters(<ConditionalTypeNode>node));
                         }
-                        else if (node.kind === SyntaxKind.VariableStatement && !isInJSFile(node)) {
-                            break;
-                        }
                         const outerAndOwnTypeParameters = appendTypeParameters(outerTypeParameters, getEffectiveTypeParameterDeclarations(<DeclarationWithTypeParameters>node));
                         const thisType = includeThisTypes &&
                             (node.kind === SyntaxKind.ClassDeclaration || node.kind === SyntaxKind.ClassExpression || node.kind === SyntaxKind.InterfaceDeclaration || isJSConstructor(node)) &&
                             getDeclaredTypeOfClassOrInterface(getSymbolOfNode(node as ClassLikeDeclaration | InterfaceDeclaration)).thisType;
                         return thisType ? append(outerAndOwnTypeParameters, thisType) : outerAndOwnTypeParameters;
+                    }
                     case SyntaxKind.JSDocParameterTag:
                         const paramSymbol = getParameterSymbolFromJSDoc(node as JSDocParameterTag);
                         if (paramSymbol) {
                             node = paramSymbol.valueDeclaration;
                         }
                         break;
+                    case SyntaxKind.JSDocComment: {
+                        const outerTypeParameters = getOuterTypeParameters(node, includeThisTypes);
+                        return (node as JSDoc).tags
+                            ? appendTypeParameters(outerTypeParameters, flatMap((node as JSDoc).tags, t => isJSDocTemplateTag(t) ? t.typeParameters : undefined))
+                            : outerTypeParameters;
+                    }
                 }
             }
         }

tests/baselines/reference/jsdocOuterTypeParameters1.errors.txt

@@ -0,0 +1,30 @@
+error TS5055: Cannot write file 'tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js' because it would overwrite input file.
+  Adding a tsconfig.json file will help organize projects that contain both TypeScript and JavaScript files. Learn more at https://aka.ms/tsconfig.
+tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js(1,14): error TS2304: Cannot find name 'T'.
+tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js(4,17): error TS2304: Cannot find name 'T'.
+tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js(4,19): error TS1069: Unexpected token. A type parameter name was expected without curly braces.
+tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js(7,35): error TS2339: Property 'foo' does not exist on type 'Bar'.
+
+
+!!! error TS5055: Cannot write file 'tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js' because it would overwrite input file.
+!!! error TS5055:   Adding a tsconfig.json file will help organize projects that contain both TypeScript and JavaScript files. Learn more at https://aka.ms/tsconfig.
+==== tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js (4 errors) ====
+    /** @return {T} */
+                 ~
+!!! error TS2304: Cannot find name 'T'.
+    const dedupingMixin = function(mixin) {};
+
+     /** @template {T} */
+                    ~
+!!! error TS2304: Cannot find name 'T'.
+                      ~
+!!! error TS1069: Unexpected token. A type parameter name was expected without curly braces.
+    const PropertyAccessors = dedupingMixin(() => {
+      class Bar {
+        static bar() { this.prototype.foo(); }
+                                      ~~~
+!!! error TS2339: Property 'foo' does not exist on type 'Bar'.
+      }
+    });
+
+

tests/baselines/reference/jsdocOuterTypeParameters1.symbols

@@ -0,0 +1,23 @@
+=== tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js ===
+/** @return {T} */
+const dedupingMixin = function(mixin) {};
+>dedupingMixin : Symbol(dedupingMixin, Decl(jsdocOuterTypeParameters1.js, 1, 5))
+>mixin : Symbol(mixin, Decl(jsdocOuterTypeParameters1.js, 1, 31))
+
+ /** @template {T} */
+const PropertyAccessors = dedupingMixin(() => {
+>PropertyAccessors : Symbol(PropertyAccessors, Decl(jsdocOuterTypeParameters1.js, 4, 5))
+>dedupingMixin : Symbol(dedupingMixin, Decl(jsdocOuterTypeParameters1.js, 1, 5))
+
+  class Bar {
+>Bar : Symbol(Bar, Decl(jsdocOuterTypeParameters1.js, 4, 47))
+
+    static bar() { this.prototype.foo(); }
+>bar : Symbol(Bar.bar, Decl(jsdocOuterTypeParameters1.js, 5, 13))
+>this.prototype : Symbol(Bar.prototype)
+>this : Symbol(Bar, Decl(jsdocOuterTypeParameters1.js, 4, 47))
+>prototype : Symbol(Bar.prototype)
+  }
+});
+
+

tests/baselines/reference/jsdocOuterTypeParameters1.types

@@ -0,0 +1,29 @@
+=== tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js ===
+/** @return {T} */
+const dedupingMixin = function(mixin) {};
+>dedupingMixin : (mixin: any) => any
+>function(mixin) {} : (mixin: any) => any
+>mixin : any
+
+ /** @template {T} */
+const PropertyAccessors = dedupingMixin(() => {
+>PropertyAccessors : any
+>dedupingMixin(() => {  class Bar {    static bar() { this.prototype.foo(); }  }}) : any
+>dedupingMixin : (mixin: any) => any
+>() => {  class Bar {    static bar() { this.prototype.foo(); }  }} : () => void
+
+  class Bar {
+>Bar : Bar
+
+    static bar() { this.prototype.foo(); }
+>bar : () => void
+>this.prototype.foo() : any
+>this.prototype.foo : any
+>this.prototype : Bar
+>this : typeof Bar
+>prototype : Bar
+>foo : any
+  }
+});
+
+

tests/baselines/reference/jsdocOuterTypeParameters2.errors.txt

@@ -0,0 +1,24 @@
+error TS5055: Cannot write file 'tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js' because it would overwrite input file.
+  Adding a tsconfig.json file will help organize projects that contain both TypeScript and JavaScript files. Learn more at https://aka.ms/tsconfig.
+tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js(1,14): error TS2355: A function whose declared type is neither 'void' nor 'any' must return a value.
+tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js(7,35): error TS2339: Property 'foo' does not exist on type 'Bar'.
+
+
+!!! error TS5055: Cannot write file 'tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js' because it would overwrite input file.
+!!! error TS5055:   Adding a tsconfig.json file will help organize projects that contain both TypeScript and JavaScript files. Learn more at https://aka.ms/tsconfig.
+==== tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js (2 errors) ====
+    /** @return {T} */
+                 ~
+!!! error TS2355: A function whose declared type is neither 'void' nor 'any' must return a value.
+    const dedupingMixin = function(mixin) {};
+
+     /** @template T */
+    const PropertyAccessors = dedupingMixin(() => {
+      class Bar {
+        static bar() { this.prototype.foo(); }
+                                      ~~~
+!!! error TS2339: Property 'foo' does not exist on type 'Bar'.
+      }
+    });
+
+

tests/baselines/reference/jsdocOuterTypeParameters2.symbols

@@ -0,0 +1,23 @@
+=== tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js ===
+/** @return {T} */
+const dedupingMixin = function(mixin) {};
+>dedupingMixin : Symbol(dedupingMixin, Decl(jsdocOuterTypeParameters1.js, 1, 5))
+>mixin : Symbol(mixin, Decl(jsdocOuterTypeParameters1.js, 1, 31))
+
+ /** @template T */
+const PropertyAccessors = dedupingMixin(() => {
+>PropertyAccessors : Symbol(PropertyAccessors, Decl(jsdocOuterTypeParameters1.js, 4, 5))
+>dedupingMixin : Symbol(dedupingMixin, Decl(jsdocOuterTypeParameters1.js, 1, 5))
+
+  class Bar {
+>Bar : Symbol(Bar, Decl(jsdocOuterTypeParameters1.js, 4, 47))
+
+    static bar() { this.prototype.foo(); }
+>bar : Symbol(Bar.bar, Decl(jsdocOuterTypeParameters1.js, 5, 13))
+>this.prototype : Symbol(Bar.prototype)
+>this : Symbol(Bar, Decl(jsdocOuterTypeParameters1.js, 4, 47))
+>prototype : Symbol(Bar.prototype)
+  }
+});
+
+

tests/baselines/reference/jsdocOuterTypeParameters2.types

@@ -0,0 +1,29 @@
+=== tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.js ===
+/** @return {T} */
+const dedupingMixin = function(mixin) {};
+>dedupingMixin : (mixin: any) => T
+>function(mixin) {} : (mixin: any) => T
+>mixin : any
+
+ /** @template T */
+const PropertyAccessors = dedupingMixin(() => {
+>PropertyAccessors : T
+>dedupingMixin(() => {  class Bar {    static bar() { this.prototype.foo(); }  }}) : T
+>dedupingMixin : (mixin: any) => T
+>() => {  class Bar {    static bar() { this.prototype.foo(); }  }} : () => void
+
+  class Bar {
+>Bar : Bar
+
+    static bar() { this.prototype.foo(); }
+>bar : () => void
+>this.prototype.foo() : any
+>this.prototype.foo : any
+>this.prototype : Bar
+>this : typeof Bar
+>prototype : Bar
+>foo : any
+  }
+});
+
+

tests/baselines/reference/jsdocOuterTypeParameters3.errors.txt

@@ -0,0 +1,25 @@
+error TS5055: Cannot write file 'tests/cases/conformance/jsdoc/jsdocOuterTypeParameters3.js' because it would overwrite input file.
+  Adding a tsconfig.json file will help organize projects that contain both TypeScript and JavaScript files. Learn more at https://aka.ms/tsconfig.
+tests/cases/conformance/jsdoc/jsdocOuterTypeParameters3.js(1,16): error TS2304: Cannot find name 'T'.
+tests/cases/conformance/jsdoc/jsdocOuterTypeParameters3.js(1,18): error TS1069: Unexpected token. A type parameter name was expected without curly braces.
+tests/cases/conformance/jsdoc/jsdocOuterTypeParameters3.js(5,43): error TS2339: Property 'foo' does not exist on type 'Bar'.
+
+
+!!! error TS5055: Cannot write file 'tests/cases/conformance/jsdoc/jsdocOuterTypeParameters3.js' because it would overwrite input file.
+!!! error TS5055:   Adding a tsconfig.json file will help organize projects that contain both TypeScript and JavaScript files. Learn more at https://aka.ms/tsconfig.
+==== tests/cases/conformance/jsdoc/jsdocOuterTypeParameters3.js (3 errors) ====
+    /** @template {T} */
+                   ~
+!!! error TS2304: Cannot find name 'T'.
+                     ~
+!!! error TS1069: Unexpected token. A type parameter name was expected without curly braces.
+    class Baz {
+        m() {
+            class Bar {
+                static bar() { this.prototype.foo(); }
+                                              ~~~
+!!! error TS2339: Property 'foo' does not exist on type 'Bar'.
+            }
+        }
+    }
+

tests/baselines/reference/jsdocOuterTypeParameters3.symbols

@@ -0,0 +1,20 @@
+=== tests/cases/conformance/jsdoc/jsdocOuterTypeParameters3.js ===
+/** @template {T} */
+class Baz {
+>Baz : Symbol(Baz, Decl(jsdocOuterTypeParameters3.js, 0, 0))
+
+    m() {
+>m : Symbol(Baz.m, Decl(jsdocOuterTypeParameters3.js, 1, 11))
+
+        class Bar {
+>Bar : Symbol(Bar, Decl(jsdocOuterTypeParameters3.js, 2, 9))
+
+            static bar() { this.prototype.foo(); }
+>bar : Symbol(Bar.bar, Decl(jsdocOuterTypeParameters3.js, 3, 19))
+>this.prototype : Symbol(Bar.prototype)
+>this : Symbol(Bar, Decl(jsdocOuterTypeParameters3.js, 2, 9))
+>prototype : Symbol(Bar.prototype)
+        }
+    }
+}
+

tests/baselines/reference/jsdocOuterTypeParameters3.types

@@ -0,0 +1,23 @@
+=== tests/cases/conformance/jsdoc/jsdocOuterTypeParameters3.js ===
+/** @template {T} */
+class Baz {
+>Baz : Baz
+
+    m() {
+>m : () => void
+
+        class Bar {
+>Bar : Bar
+
+            static bar() { this.prototype.foo(); }
+>bar : () => void
+>this.prototype.foo() : any
+>this.prototype.foo : any
+>this.prototype : Bar
+>this : typeof Bar
+>prototype : Bar
+>foo : any
+        }
+    }
+}
+

tests/cases/conformance/jsdoc/jsdocOuterTypeParameters1.ts

@@ -0,0 +1,12 @@
+// @checkjs: true
+// @filename: jsdocOuterTypeParameters1.js
+/** @return {T} */
+const dedupingMixin = function(mixin) {};
+
+ /** @template {T} */
+const PropertyAccessors = dedupingMixin(() => {
+  class Bar {
+    static bar() { this.prototype.foo(); }
+  }
+});
+

tests/cases/conformance/jsdoc/jsdocOuterTypeParameters2.ts

@@ -0,0 +1,12 @@
+// @checkjs: true
+// @filename: jsdocOuterTypeParameters1.js
+/** @return {T} */
+const dedupingMixin = function(mixin) {};
+
+ /** @template T */
+const PropertyAccessors = dedupingMixin(() => {
+  class Bar {
+    static bar() { this.prototype.foo(); }
+  }
+});
+

tests/cases/conformance/jsdoc/jsdocOuterTypeParameters3.ts

@@ -0,0 +1,11 @@
+// @checkjs: true
+// @filename: jsdocOuterTypeParameters3.js
+
+/** @template {T} */
+class Baz {
+    m() {
+        class Bar {
+            static bar() { this.prototype.foo(); }
+        }
+    }
+}