Expose getStringLiteralType and getNumberLiteralType on the TypeChecker, plus remove /** @internal */ from several useful methods. (#52473)

Co-authored-by: Stephen Stchur <stchur@microsoft.com>
Co-authored-by: Andrew Branch <andrew@wheream.io>

Author: 3 people

src/compiler/checker.ts

@@ -1710,7 +1710,10 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         createIndexInfo,
         getAnyType: () => anyType,
         getStringType: () => stringType,
+        getStringLiteralType,
         getNumberType: () => numberType,
+        getNumberLiteralType,
+        getBigIntType: () => bigintType,
         createPromiseType,
         createArrayType,
         getElementTypeOfArrayType,

src/compiler/types.ts

@@ -5099,17 +5099,46 @@ export interface TypeChecker {
     getBaseConstraintOfType(type: Type): Type | undefined;
     getDefaultFromTypeParameter(type: Type): Type | undefined;
 
-    /** @internal */ getAnyType(): Type;
-    /** @internal */ getStringType(): Type;
-    /** @internal */ getNumberType(): Type;
-    /** @internal */ getBooleanType(): Type;
-    /** @internal */ getFalseType(fresh?: boolean): Type;
-    /** @internal */ getTrueType(fresh?: boolean): Type;
-    /** @internal */ getVoidType(): Type;
-    /** @internal */ getUndefinedType(): Type;
-    /** @internal */ getNullType(): Type;
-    /** @internal */ getESSymbolType(): Type;
-    /** @internal */ getNeverType(): Type;
+    /**
+     * Gets the intrinsic `any` type. There are multiple types that act as `any` used internally in the compiler,
+     * so the type returned by this function should not be used in equality checks to determine if another type
+     * is `any`. Instead, use `type.flags & TypeFlags.Any`.
+     */
+    getAnyType(): Type;
+    getStringType(): Type;
+    getStringLiteralType(value: string): StringLiteralType;
+    getNumberType(): Type;
+    getNumberLiteralType(value: number): NumberLiteralType;
+    getBigIntType(): Type;
+    getBooleanType(): Type;
+    /* eslint-disable @typescript-eslint/unified-signatures */
+    /** @internal */
+    getFalseType(fresh?: boolean): Type;
+    getFalseType(): Type;
+    /** @internal */
+    getTrueType(fresh?: boolean): Type;
+    getTrueType(): Type;
+    /* eslint-enable @typescript-eslint/unified-signatures */
+    getVoidType(): Type;
+    /**
+     * Gets the intrinsic `undefined` type. There are multiple types that act as `undefined` used internally in the compiler
+     * depending on compiler options, so the type returned by this function should not be used in equality checks to determine
+     * if another type is `undefined`. Instead, use `type.flags & TypeFlags.Undefined`.
+     */
+    getUndefinedType(): Type;
+    /**
+     * Gets the intrinsic `null` type. There are multiple types that act as `null` used internally in the compiler,
+     * so the type returned by this function should not be used in equality checks to determine if another type
+     * is `null`. Instead, use `type.flags & TypeFlags.Null`.
+     */
+    getNullType(): Type;
+    getESSymbolType(): Type;
+    /**
+     * Gets the intrinsic `never` type. There are multiple types that act as `never` used internally in the compiler,
+     * so the type returned by this function should not be used in equality checks to determine if another type
+     * is `never`. Instead, use `type.flags & TypeFlags.Never`.
+     */
+    getNeverType(): Type;
     /** @internal */ getOptionalType(): Type;
     /** @internal */ getUnionType(types: Type[], subtypeReduction?: UnionReduction): Type;
     /** @internal */ createArrayType(elementType: Type): Type;

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -6369,6 +6369,40 @@ declare namespace ts {
         getApparentType(type: Type): Type;
         getBaseConstraintOfType(type: Type): Type | undefined;
         getDefaultFromTypeParameter(type: Type): Type | undefined;
+        /**
+         * Gets the intrinsic `any` type. There are multiple types that act as `any` used internally in the compiler,
+         * so the type returned by this function should not be used in equality checks to determine if another type
+         * is `any`. Instead, use `type.flags & TypeFlags.Any`.
+         */
+        getAnyType(): Type;
+        getStringType(): Type;
+        getStringLiteralType(value: string): StringLiteralType;
+        getNumberType(): Type;
+        getNumberLiteralType(value: number): NumberLiteralType;
+        getBigIntType(): Type;
+        getBooleanType(): Type;
+        getFalseType(): Type;
+        getTrueType(): Type;
+        getVoidType(): Type;
+        /**
+         * Gets the intrinsic `undefined` type. There are multiple types that act as `undefined` used internally in the compiler
+         * depending on compiler options, so the type returned by this function should not be used in equality checks to determine
+         * if another type is `undefined`. Instead, use `type.flags & TypeFlags.Undefined`.
+         */
+        getUndefinedType(): Type;
+        /**
+         * Gets the intrinsic `null` type. There are multiple types that act as `null` used internally in the compiler,
+         * so the type returned by this function should not be used in equality checks to determine if another type
+         * is `null`. Instead, use `type.flags & TypeFlags.Null`.
+         */
+        getNullType(): Type;
+        getESSymbolType(): Type;
+        /**
+         * Gets the intrinsic `never` type. There are multiple types that act as `never` used internally in the compiler,
+         * so the type returned by this function should not be used in equality checks to determine if another type
+         * is `never`. Instead, use `type.flags & TypeFlags.Never`.
+         */
+        getNeverType(): Type;
         /**
          * True if this type is the `Array` or `ReadonlyArray` type from lib.d.ts.
          * This function will _not_ return true if passed a type which

tests/baselines/reference/api/typescript.d.ts

@@ -2426,6 +2426,40 @@ declare namespace ts {
         getApparentType(type: Type): Type;
         getBaseConstraintOfType(type: Type): Type | undefined;
         getDefaultFromTypeParameter(type: Type): Type | undefined;
+        /**
+         * Gets the intrinsic `any` type. There are multiple types that act as `any` used internally in the compiler,
+         * so the type returned by this function should not be used in equality checks to determine if another type
+         * is `any`. Instead, use `type.flags & TypeFlags.Any`.
+         */
+        getAnyType(): Type;
+        getStringType(): Type;
+        getStringLiteralType(value: string): StringLiteralType;
+        getNumberType(): Type;
+        getNumberLiteralType(value: number): NumberLiteralType;
+        getBigIntType(): Type;
+        getBooleanType(): Type;
+        getFalseType(): Type;
+        getTrueType(): Type;
+        getVoidType(): Type;
+        /**
+         * Gets the intrinsic `undefined` type. There are multiple types that act as `undefined` used internally in the compiler
+         * depending on compiler options, so the type returned by this function should not be used in equality checks to determine
+         * if another type is `undefined`. Instead, use `type.flags & TypeFlags.Undefined`.
+         */
+        getUndefinedType(): Type;
+        /**
+         * Gets the intrinsic `null` type. There are multiple types that act as `null` used internally in the compiler,
+         * so the type returned by this function should not be used in equality checks to determine if another type
+         * is `null`. Instead, use `type.flags & TypeFlags.Null`.
+         */
+        getNullType(): Type;
+        getESSymbolType(): Type;
+        /**
+         * Gets the intrinsic `never` type. There are multiple types that act as `never` used internally in the compiler,
+         * so the type returned by this function should not be used in equality checks to determine if another type
+         * is `never`. Instead, use `type.flags & TypeFlags.Never`.
+         */
+        getNeverType(): Type;
         /**
          * True if this type is the `Array` or `ReadonlyArray` type from lib.d.ts.
          * This function will _not_ return true if passed a type which