visit: remove template arguments for possible nodes

src/index.d.ts

@@ -227,8 +227,7 @@ export {
   DirectiveLocationEnum,
   // Visitor utilities
   ASTVisitor,
-  Visitor,
-  VisitFn,
+  ASTVisitFn,
   // AST nodes
   ASTNode,
   ASTKindToNode,

src/index.js

@@ -214,8 +214,7 @@ export type {
   DirectiveLocationEnum,
   // Visitor utilities
   ASTVisitor,
-  Visitor,
-  VisitFn,
+  ASTVisitFn,
   // AST nodes
   ASTNode,
   ASTKindToNode,

src/language/index.d.ts

@@ -14,8 +14,7 @@ export {
   getVisitFn,
   BREAK,
   ASTVisitor,
-  Visitor,
-  VisitFn,
+  ASTVisitFn,
 } from './visitor';
 
 export {

src/language/index.js

@@ -19,7 +19,7 @@ export type { ParseOptions } from './parser';
 export { print } from './printer';
 
 export { visit, visitInParallel, getVisitFn, BREAK } from './visitor';
-export type { ASTVisitor, Visitor, VisitFn } from './visitor';
+export type { ASTVisitor, ASTVisitFn } from './visitor';
 
 export { Location, Token } from './ast';
 export type {

src/language/visitor.d.ts

@@ -6,45 +6,43 @@ import { ASTNode, ASTKindToNode } from './ast';
  * A visitor is provided to visit, it contains the collection of
  * relevant functions to be called during the visitor's traversal.
  */
-export type ASTVisitor = Visitor<ASTKindToNode>;
-export type Visitor<KindToNode, Nodes = KindToNode[keyof KindToNode]> =
-  | EnterLeaveVisitor<KindToNode, Nodes>
-  | ShapeMapVisitor<KindToNode, Nodes>;
+export type ASTVisitor = EnterLeaveVisitor | ShapeMapVisitor;
 
 interface EnterLeave<T> {
   readonly enter?: T;
   readonly leave?: T;
 }
 
-type EnterLeaveVisitor<KindToNode, Nodes> = EnterLeave<
-  VisitFn<Nodes> | { [K in keyof KindToNode]?: VisitFn<Nodes, KindToNode[K]> }
+type EnterLeaveVisitor = EnterLeave<
+  | ASTVisitFn<ASTNode>
+  | { [K in keyof ASTKindToNode]?: ASTVisitFn<ASTKindToNode[K]> }
 >;
 
-type ShapeMapVisitor<KindToNode, Nodes> = {
-  [K in keyof KindToNode]?:
-    | VisitFn<Nodes, KindToNode[K]>
-    | EnterLeave<VisitFn<Nodes, KindToNode[K]>>;
+type ShapeMapVisitor = {
+  [K in keyof ASTKindToNode]?:
+    | ASTVisitFn<ASTKindToNode[K]>
+    | EnterLeave<ASTVisitFn<ASTKindToNode[K]>>;
 };
 
 /**
  * A visitor is comprised of visit functions, which are called on each node
  * during the visitor's traversal.
  */
-export type VisitFn<TAnyNode, TVisitedNode = TAnyNode> = (
+export type ASTVisitFn<TVisitedNode extends ASTNode> = (
   /** The current node being visiting. */
   node: TVisitedNode,
   /** The index or key to this node from the parent node or Array. */
   key: string | number | undefined,
   /** The parent immediately above this node, which may be an Array. */
-  parent: TAnyNode | ReadonlyArray<TAnyNode> | undefined,
+  parent: ASTNode | ReadonlyArray<ASTNode> | undefined,
   /** The key path to get to this node from the root node. */
   path: ReadonlyArray<string | number>,
   /**
    * All nodes and Arrays visited before reaching parent of this node.
    * These correspond to array indices in `path`.
    * Note: ancestors includes arrays which contain the parent of visited node.
    */
-  ancestors: ReadonlyArray<TAnyNode | ReadonlyArray<TAnyNode>>,
+  ancestors: ReadonlyArray<ASTNode | ReadonlyArray<ASTNode>>,
 ) => any;
 
 export const BREAK: any;
@@ -135,7 +133,7 @@ export const BREAK: any;
  *       }
  *     })
  */
-export function visit(root: ASTNode, visitor: Visitor<ASTKindToNode>): any;
+export function visit(root: ASTNode, visitor: ASTVisitor): any;
 
 /**
  * Creates a new visitor instance which delegates to many visitors to run in
@@ -144,15 +142,15 @@ export function visit(root: ASTNode, visitor: Visitor<ASTKindToNode>): any;
  * If a prior visitor edits a node, no following visitors will see that node.
  */
 export function visitInParallel(
-  visitors: ReadonlyArray<Visitor<ASTKindToNode>>,
-): Visitor<ASTKindToNode>;
+  visitors: ReadonlyArray<ASTVisitor>,
+): ASTVisitor;
 
 /**
  * Given a visitor instance, if it is leaving or not, and a node kind, return
  * the function the visitor runtime should call.
  */
 export function getVisitFn(
-  visitor: Visitor<any>,
+  visitor: ASTVisitor,
   kind: string,
   isLeaving: boolean,
-): Maybe<VisitFn<any>>;
+): Maybe<ASTVisitFn<ASTNode>>;

src/language/visitor.js

@@ -7,15 +7,14 @@ import { isNode } from './ast';
  * A visitor is provided to visit, it contains the collection of
  * relevant functions to be called during the visitor's traversal.
  */
-export type ASTVisitor = Visitor<ASTKindToNode>;
-export type Visitor<KindToNode, Nodes = $Values<KindToNode>> =
+export type ASTVisitor =
   | EnterLeave<
-      | VisitFn<Nodes>
-      | ShapeMap<KindToNode, <Node>(Node) => VisitFn<Nodes, Node>>,
+      | ASTVisitFn<ASTNode>
+      | ShapeMap<ASTKindToNode, <Node>(Node) => ASTVisitFn<Node>>,
     >
   | ShapeMap<
-      KindToNode,
-      <Node>(Node) => VisitFn<Nodes, Node> | EnterLeave<VisitFn<Nodes, Node>>,
+      ASTKindToNode,
+      <Node>(Node) => ASTVisitFn<Node> | EnterLeave<ASTVisitFn<Node>>,
     >;
 type EnterLeave<T> = {| +enter?: T, +leave?: T |};
 type ShapeMap<O, F> = $Shape<$ObjMap<O, F>>;
@@ -24,19 +23,19 @@ type ShapeMap<O, F> = $Shape<$ObjMap<O, F>>;
  * A visitor is comprised of visit functions, which are called on each node
  * during the visitor's traversal.
  */
-export type VisitFn<TAnyNode, TVisitedNode: TAnyNode = TAnyNode> = (
+export type ASTVisitFn<TVisitedNode: ASTNode> = (
   // The current node being visiting.
   node: TVisitedNode,
   // The index or key to this node from the parent node or Array.
   key: string | number | void,
   // The parent immediately above this node, which may be an Array.
-  parent: TAnyNode | $ReadOnlyArray<TAnyNode> | void,
+  parent: ASTNode | $ReadOnlyArray<ASTNode> | void,
   // The key path to get to this node from the root node.
   path: $ReadOnlyArray<string | number>,
   // All nodes and Arrays visited before reaching parent of this node.
   // These correspond to array indices in `path`.
   // Note: ancestors includes arrays which contain the parent of visited node.
-  ancestors: $ReadOnlyArray<TAnyNode | $ReadOnlyArray<TAnyNode>>,
+  ancestors: $ReadOnlyArray<ASTNode | $ReadOnlyArray<ASTNode>>,
 ) => any;
 
 const QueryDocumentKeys = {
@@ -213,7 +212,7 @@ export const BREAK: { ... } = Object.freeze({});
  *       }
  *     })
  */
-export function visit(root: ASTNode, visitor: Visitor<ASTKindToNode>): any {
+export function visit(root: ASTNode, visitor: ASTVisitor): any {
   /* eslint-disable no-undef-init */
   let stack: any = undefined;
   let inArray = Array.isArray(root);
@@ -284,6 +283,7 @@ export function visit(root: ASTNode, visitor: Visitor<ASTKindToNode>): any {
       }
       const visitFn = getVisitFn(visitor, node.kind, isLeaving);
       if (visitFn) {
+        // $FlowFixMe[incompatible-call]
         result = visitFn.call(visitor, node, key, parent, path, ancestors);
 
         if (result === BREAK) {
@@ -342,8 +342,8 @@ export function visit(root: ASTNode, visitor: Visitor<ASTKindToNode>): any {
  * If a prior visitor edits a node, no following visitors will see that node.
  */
 export function visitInParallel(
-  visitors: $ReadOnlyArray<Visitor<ASTKindToNode>>,
-): Visitor<ASTKindToNode> {
+  visitors: $ReadOnlyArray<ASTVisitor>,
+): ASTVisitor {
   const skipping = new Array(visitors.length);
 
   return {
@@ -389,10 +389,10 @@ export function visitInParallel(
  * the function the visitor runtime should call.
  */
 export function getVisitFn(
-  visitor: Visitor<any>,
+  visitor: ASTVisitor,
   kind: string,
   isLeaving: boolean,
-): ?VisitFn<any> {
+): ?ASTVisitFn<ASTNode> {
   const kindVisitor = visitor[kind];
   if (kindVisitor) {
     if (!isLeaving && typeof kindVisitor === 'function') {
@@ -407,6 +407,7 @@ export function getVisitFn(
       return kindSpecificVisitor;
     }
   } else {
+    // $FlowFixMe[prop-missing]
     const specificVisitor = isLeaving ? visitor.leave : visitor.enter;
     if (specificVisitor) {
       if (typeof specificVisitor === 'function') {

src/utilities/TypeInfo.d.ts

@@ -1,6 +1,6 @@
 import { Maybe } from '../jsutils/Maybe';
 
-import { Visitor } from '../language/visitor';
+import { ASTVisitor } from '../language/visitor';
 import { ASTNode, ASTKindToNode, FieldNode } from '../language/ast';
 import { GraphQLSchema } from '../type/schema';
 import { GraphQLDirective } from '../type/directives';

src/utilities/TypeInfo.js

@@ -1,5 +1,5 @@
-import type { Visitor } from '../language/visitor';
-import type { ASTNode, ASTKindToNode, FieldNode } from '../language/ast';
+import type { ASTVisitor } from '../language/visitor';
+import type { ASTNode, FieldNode } from '../language/ast';
 import { Kind } from '../language/kinds';
 import { isNode } from '../language/ast';
 import { getVisitFn } from '../language/visitor';
@@ -324,8 +324,8 @@ function getFieldDef(
  */
 export function visitWithTypeInfo(
   typeInfo: TypeInfo,
-  visitor: Visitor<ASTKindToNode>,
-): Visitor<ASTKindToNode> {
+  visitor: ASTVisitor,
+): ASTVisitor {
   return {
     enter(node) {
       typeInfo.enter(node);