feat: Support for TypeScript 4.2

Resolves TypeStrong#1517

Author: Gerrit0

examples/basic/src/classes.ts

@@ -321,3 +321,6 @@ export class GenericClass<T extends BaseClass> {
  * This a non generic class derived from a [[GenericClass|generic class]].
  */
 export class NonGenericClass extends GenericClass<SubClassB> {}
+
+// TS 4.2
+export type AbstractMe = abstract new () => NonGenericClass

package-lock.json

@@ -30,10 +30,10 @@
     "progress": "^2.0.3",
     "shelljs": "^0.8.4",
     "shiki": "^0.9.2",
-    "typedoc-default-themes": "^0.12.7"
+    "typedoc-default-themes": "^0.12.8"
   },
   "peerDependencies": {
-    "typescript": "3.9.x || 4.0.x || 4.1.x"
+    "typescript": "3.9.x || 4.0.x || 4.1.x || 4.2.x"
   },
   "devDependencies": {
     "@types/fs-extra": "^9.0.7",
@@ -53,7 +53,7 @@
     "mockery": "^2.1.0",
     "nyc": "^15.1.0",
     "prettier": "^2.2.1",
-    "typescript": "^4.1.5"
+    "typescript": "^4.2.2"
   },
   "files": [
     "bin",

package.json

@@ -16,15 +16,18 @@ export { UrlMapping } from "./lib/output/models/UrlMapping";
 export {
     BindOption,
     Options,
-    OptionsReader,
     ParameterHint,
     ParameterType,
-    TypeDocOptions,
-    TypeDocOptionMap,
-    KeyToDeclaration,
     TSConfigReader,
     TypeDocReader,
     ArgumentsReader,
+} from "./lib/utils/options";
+
+export type {
+    OptionsReader,
+    TypeDocOptions,
+    TypeDocOptionMap,
+    KeyToDeclaration,
     DeclarationOption,
     DeclarationOptionBase,
     StringDeclarationOption,

src/index.ts

@@ -22,6 +22,7 @@ import {
     UnknownType,
     MappedType,
     SignatureReflection,
+    ReflectionFlag,
 } from "../models";
 import { OptionalType } from "../models/types/optional";
 import { RestType } from "../models/types/rest";
@@ -103,7 +104,7 @@ const seenTypeSymbols = new Set<ts.Symbol>();
 export function convertType(
     context: Context,
     typeOrNode: ts.Type | ts.TypeNode | undefined
-) {
+): Type {
     if (!typeOrNode) {
         return new IntrinsicType("any");
     }
@@ -117,6 +118,11 @@ export function convertType(
         return requestBugReport(context, typeOrNode);
     }
 
+    // TS 4.2 added this to enable better tracking of type aliases.
+    if (typeOrNode.isUnion() && typeOrNode.origin) {
+        return convertType(context, typeOrNode.origin);
+    }
+
     // IgnoreErrors is important, without it, we can't assert that we will get a node.
     const node = context.checker.typeToTypeNode(
         typeOrNode,
@@ -213,6 +219,16 @@ const constructorConverter: TypeConverter<ts.ConstructorTypeNode, ts.Type> = {
             ReflectionKind.ConstructorSignature,
             reflection
         );
+        // This is unfortunate... but seems the obvious place to put this with the current
+        // architecture. Ideally, this would be a property on a "ConstructorType"... but that
+        // needs to wait until TypeDoc 0.22 when making other breaking changes.
+        if (
+            node.modifiers?.some(
+                (m) => m.kind === ts.SyntaxKind.AbstractKeyword
+            )
+        ) {
+            signature.setFlag(ReflectionFlag.Abstract);
+        }
         context.registerReflection(signature, void 0);
         const signatureCtx = rc.withScope(signature);
 

src/lib/converter/types.ts

@@ -2,13 +2,13 @@ export {
     Reflection,
     ReflectionKind,
     ReflectionFlag,
-    TypeParameterContainer,
-    Decorator,
     TraverseProperty,
     ReflectionFlags,
 } from "./abstract";
+export type { TypeParameterContainer, Decorator } from "./abstract";
 export { ContainerReflection } from "./container";
-export { DeclarationReflection, DeclarationHierarchy } from "./declaration";
+export { DeclarationReflection } from "./declaration";
+export type { DeclarationHierarchy } from "./declaration";
 export { ParameterReflection } from "./parameter";
 export { ProjectReflection } from "./project";
 export { ReferenceReflection } from "./reference";

src/lib/models/reflections/index.ts

@@ -1,2 +1,3 @@
 export { SourceDirectory } from "./directory";
-export { SourceFile, SourceReference } from "./file";
+export { SourceFile } from "./file";
+export type { SourceReference } from "./file";

src/lib/models/sources/index.ts

@@ -22,9 +22,15 @@ declare module "typescript" {
         ): ts.TypePredicate | undefined;
     }
 
+    // https://github.com/microsoft/TypeScript/blob/e213b2af3430bdc9cf5fbc76a8634d832e7aaaaa/src/compiler/types.ts#L5298-L5299
+    export interface UnionType {
+        /* @internal */
+        origin?: ts.Type; // Denormalized union, intersection, or index type in which union originates
+    }
+
     // https://github.com/microsoft/TypeScript/blob/v4.1.5/src/compiler/types.ts#L4707-L4732
     /* @internal */
-    export const enum CheckFlags {
+    export enum CheckFlags {
         Instantiated = 1 << 0, // Instantiated symbol
         SyntheticProperty = 1 << 1, // Property in union or intersection type
         SyntheticMethod = 1 << 2, // Method in union or intersection type

src/lib/ts-internal.ts

@@ -1,11 +1,12 @@
-export { Options, OptionsReader, BindOption } from "./options";
+export { Options, BindOption } from "./options";
+export type { OptionsReader } from "./options";
 export { ArgumentsReader, TypeDocReader, TSConfigReader } from "./readers";
-export {
+export { ParameterType, ParameterHint } from "./declaration";
+
+export type {
     TypeDocOptions,
     TypeDocOptionMap,
     KeyToDeclaration,
-    ParameterType,
-    ParameterHint,
     DeclarationOption,
     DeclarationOptionBase,
     StringDeclarationOption,

src/lib/utils/options/index.ts

@@ -130,3 +130,10 @@ export namespace GH1509 {
     export interface PartialFoo extends Partial<Foo> {}
     export interface ReadonlyFoo extends Readonly<Partial<Foo>> {}
 }
+
+export abstract class Abstract {
+    abstract needsImpl(): number
+}
+
+// TS 4.2
+export type AbstractMe = abstract new () => Abstract