[@typescript/api] Add a few more checker APIs (#2972)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: andrewbranch

Herebyfile.mjs

@@ -313,6 +313,7 @@ const enumDefs = [
     { name: "SignatureFlags", goPrefix: "SignatureFlags", goFile: "internal/checker/types.go", outDir: "_packages/api/src/enums" },
     { name: "SignatureKind", goPrefix: "SignatureKind", goFile: "internal/checker/types.go", outDir: "_packages/api/src/enums" },
     { name: "ElementFlags", goPrefix: "ElementFlags", goFile: "internal/checker/types.go", outDir: "_packages/api/src/enums" },
+    { name: "TypePredicateKind", goPrefix: "TypePredicateKind", goFile: "internal/checker/types.go", outDir: "_packages/api/src/enums" },
     // @typescript/ast enums
     { name: "SyntaxKind", goPrefix: "Kind", goFile: "internal/ast/kind.go", outDir: "_packages/ast/src/enums" },
     { name: "NodeFlags", goPrefix: "NodeFlags", goFile: "internal/ast/nodeflags.go", outDir: "_packages/ast/src/enums" },

_packages/api/src/async/api.ts

@@ -5,6 +5,7 @@ import { SignatureFlags } from "#enums/signatureFlags";
 import { SignatureKind } from "#enums/signatureKind";
 import { SymbolFlags } from "#enums/symbolFlags";
 import { TypeFlags } from "#enums/typeFlags";
+import { TypePredicateKind } from "#enums/typePredicateKind";
 import type {
     Expression,
     Node,
@@ -39,11 +40,13 @@ import type {
     ConfigResponse,
     DocumentIdentifier,
     DocumentPosition,
+    IndexInfoResponse,
     InitializeResponse,
     LSPUpdateSnapshotParams,
     ProjectResponse,
     SignatureResponse,
     SymbolResponse,
+    TypePredicateResponse,
     TypeResponse,
     UpdateSnapshotParams,
     UpdateSnapshotResponse,
@@ -56,8 +59,12 @@ import {
     type ClientSpawnOptions,
 } from "./client.ts";
 import type {
+    AssertsIdentifierTypePredicate,
+    AssertsThisTypePredicate,
     ConditionalType,
+    IdentifierTypePredicate,
     IndexedAccessType,
+    IndexInfo,
     IndexType,
     InterfaceType,
     IntersectionType,
@@ -66,17 +73,20 @@ import type {
     StringMappingType,
     SubstitutionType,
     TemplateLiteralType,
+    ThisTypePredicate,
     TupleType,
     Type,
     TypeParameter,
+    TypePredicate,
+    TypePredicateBase,
     TypeReference,
     UnionOrIntersectionType,
     UnionType,
 } from "./types.ts";
 
-export { ElementFlags, ObjectFlags, SignatureFlags, SignatureKind, SymbolFlags, TypeFlags };
+export { ElementFlags, ObjectFlags, SignatureFlags, SignatureKind, SymbolFlags, TypeFlags, TypePredicateKind };
 export type { APIOptions, ClientSocketOptions, ClientSpawnOptions, DocumentIdentifier, DocumentPosition, LSPConnectionOptions };
-export type { ConditionalType, IndexedAccessType, IndexType, InterfaceType, IntersectionType, LiteralType, ObjectType, StringMappingType, SubstitutionType, TemplateLiteralType, TupleType, TypeParameter, TypeReference, UnionOrIntersectionType, UnionType };
+export type { AssertsIdentifierTypePredicate, AssertsThisTypePredicate, ConditionalType, IdentifierTypePredicate, IndexedAccessType, IndexInfo, IndexType, InterfaceType, IntersectionType, LiteralType, ObjectType, StringMappingType, SubstitutionType, TemplateLiteralType, ThisTypePredicate, TupleType, TypeParameter, TypePredicate, TypePredicateBase, TypeReference, UnionOrIntersectionType, UnionType };
 export { documentURIToFileName, fileNameToDocumentURI } from "../path.ts";
 
 /** Type alias for the snapshot-scoped object registry */
@@ -601,6 +611,97 @@ export class Checker {
             flags,
         });
     }
+
+    async isContextSensitive(node: Node): Promise<boolean> {
+        return this.client.apiRequest<boolean>("isContextSensitive", {
+            snapshot: this.snapshotId,
+            project: this.projectId,
+            location: getNodeId(node),
+        });
+    }
+
+    async getReturnTypeOfSignature(signature: Signature): Promise<Type | undefined> {
+        const data = await this.client.apiRequest<TypeResponse | null>("getReturnTypeOfSignature", {
+            snapshot: this.snapshotId,
+            project: this.projectId,
+            signature: signature.id,
+        });
+        return data ? this.objectRegistry.getOrCreateType(data) : undefined;
+    }
+
+    async getRestTypeOfSignature(signature: Signature): Promise<Type | undefined> {
+        const data = await this.client.apiRequest<TypeResponse | null>("getRestTypeOfSignature", {
+            snapshot: this.snapshotId,
+            project: this.projectId,
+            signature: signature.id,
+        });
+        return data ? this.objectRegistry.getOrCreateType(data) : undefined;
+    }
+
+    async getTypePredicateOfSignature(signature: Signature): Promise<TypePredicate | undefined> {
+        const data = await this.client.apiRequest<TypePredicateResponse | null>("getTypePredicateOfSignature", {
+            snapshot: this.snapshotId,
+            project: this.projectId,
+            signature: signature.id,
+        });
+        if (!data) return undefined;
+        return {
+            kind: data.kind,
+            parameterIndex: data.parameterIndex,
+            parameterName: data.parameterName,
+            type: data.type ? this.objectRegistry.getOrCreateType(data.type) : undefined,
+        } as TypePredicate;
+    }
+
+    async getBaseTypes(type: Type): Promise<readonly Type[]> {
+        const data = await this.client.apiRequest<TypeResponse[] | null>("getBaseTypes", {
+            snapshot: this.snapshotId,
+            project: this.projectId,
+            type: type.id,
+        });
+        return data ? data.map(d => this.objectRegistry.getOrCreateType(d)) : [];
+    }
+
+    async getPropertiesOfType(type: Type): Promise<readonly Symbol[]> {
+        const data = await this.client.apiRequest<SymbolResponse[] | null>("getPropertiesOfType", {
+            snapshot: this.snapshotId,
+            project: this.projectId,
+            type: type.id,
+        });
+        return data ? data.map(d => this.objectRegistry.getOrCreateSymbol(d)) : [];
+    }
+
+    async getIndexInfosOfType(type: Type): Promise<readonly IndexInfo[]> {
+        const data = await this.client.apiRequest<IndexInfoResponse[] | null>("getIndexInfosOfType", {
+            snapshot: this.snapshotId,
+            project: this.projectId,
+            type: type.id,
+        });
+        if (!data) return [];
+        return data.map(d => ({
+            keyType: this.objectRegistry.getOrCreateType(d.keyType),
+            valueType: this.objectRegistry.getOrCreateType(d.valueType),
+            isReadonly: d.isReadonly ?? false,
+        }));
+    }
+
+    async getConstraintOfTypeParameter(type: Type): Promise<Type | undefined> {
+        const data = await this.client.apiRequest<TypeResponse | null>("getConstraintOfTypeParameter", {
+            snapshot: this.snapshotId,
+            project: this.projectId,
+            type: type.id,
+        });
+        return data ? this.objectRegistry.getOrCreateType(data) : undefined;
+    }
+
+    async getTypeArguments(type: Type): Promise<readonly Type[]> {
+        const data = await this.client.apiRequest<TypeResponse[] | null>("getTypeArguments", {
+            snapshot: this.snapshotId,
+            project: this.projectId,
+            type: type.id,
+        });
+        return data ? data.map(d => this.objectRegistry.getOrCreateType(d)) : [];
+    }
 }
 
 export class Emitter {

_packages/api/src/async/types.ts

@@ -1,6 +1,7 @@
 import type { ElementFlags } from "#enums/elementFlags";
 import type { ObjectFlags } from "#enums/objectFlags";
 import type { TypeFlags } from "#enums/typeFlags";
+import type { TypePredicateKind } from "#enums/typePredicateKind";
 import type { Symbol } from "./api.ts";
 
 /**
@@ -122,3 +123,54 @@ export interface StringMappingType extends Type {
     /** Get the mapped type */
     getTarget(): Promise<Type>;
 }
+
+/** Base for all type predicates */
+export interface TypePredicateBase {
+    readonly kind: TypePredicateKind;
+    readonly type: Type | undefined;
+}
+
+/** `this is T` */
+export interface ThisTypePredicate extends TypePredicateBase {
+    readonly kind: TypePredicateKind.This;
+    readonly parameterName: undefined;
+    readonly parameterIndex: undefined;
+    readonly type: Type;
+}
+
+/** `x is T` */
+export interface IdentifierTypePredicate extends TypePredicateBase {
+    readonly kind: TypePredicateKind.Identifier;
+    readonly parameterName: string;
+    readonly parameterIndex: number;
+    readonly type: Type;
+}
+
+/** `asserts this is T` */
+export interface AssertsThisTypePredicate extends TypePredicateBase {
+    readonly kind: TypePredicateKind.AssertsThis;
+    readonly parameterName: undefined;
+    readonly parameterIndex: undefined;
+    readonly type: Type | undefined;
+}
+
+/** `asserts x is T` */
+export interface AssertsIdentifierTypePredicate extends TypePredicateBase {
+    readonly kind: TypePredicateKind.AssertsIdentifier;
+    readonly parameterName: string;
+    readonly parameterIndex: number;
+    readonly type: Type | undefined;
+}
+
+/** A type predicate — e.g. `x is T` or `asserts x is T` */
+export type TypePredicate = ThisTypePredicate | IdentifierTypePredicate | AssertsThisTypePredicate | AssertsIdentifierTypePredicate;
+
+/** An index signature — e.g. `[key: string]: T` */
+export interface IndexInfo {
+    /** The index key type (e.g. string or number) */
+    readonly keyType: Type;
+    /** The index value type */
+    readonly valueType: Type;
+    /** Whether the index signature is readonly */
+    readonly isReadonly: boolean;
+}

_packages/api/src/enums/typePredicateKind.enum.ts

@@ -0,0 +1,14 @@
+//
+// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+// !!! THIS FILE IS AUTO-GENERATED — DO NOT EDIT !!!
+// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+//
+// Source: internal/checker/types.go
+// Regenerate: npx hereby generate:enums
+//
+export enum TypePredicateKind {
+    This = 0,
+    Identifier = 1,
+    AssertsThis = 2,
+    AssertsIdentifier = 3,
+}

_packages/api/src/enums/typePredicateKind.ts

@@ -0,0 +1,15 @@
+//
+// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+// !!! THIS FILE IS AUTO-GENERATED — DO NOT EDIT !!!
+// !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+//
+// Source: internal/checker/types.go
+// Regenerate: npx hereby generate:enums
+//
+export var TypePredicateKind: any;
+(function (TypePredicateKind) {
+    TypePredicateKind[TypePredicateKind["This"] = 0] = "This";
+    TypePredicateKind[TypePredicateKind["Identifier"] = 1] = "Identifier";
+    TypePredicateKind[TypePredicateKind["AssertsThis"] = 2] = "AssertsThis";
+    TypePredicateKind[TypePredicateKind["AssertsIdentifier"] = 3] = "AssertsIdentifier";
+})(TypePredicateKind || (TypePredicateKind = {}));

_packages/api/src/proto.ts

@@ -166,3 +166,16 @@ export interface SignatureResponse {
     thisParameter?: string;
     target?: string;
 }
+
+export interface TypePredicateResponse {
+    kind: number;
+    parameterIndex: number;
+    parameterName?: string;
+    type?: TypeResponse;
+}
+
+export interface IndexInfoResponse {
+    keyType: TypeResponse;
+    valueType: TypeResponse;
+    isReadonly?: boolean;
+}