MessagesForMacintosh/JS/node_modules/graphql/language/visitor.mjs

384 lines
11 KiB
JavaScript

import inspect from "../jsutils/inspect.mjs";
import { isNode } from "./ast.mjs";
/**
* A visitor is provided to visit, it contains the collection of
* relevant functions to be called during the visitor's traversal.
*/
export var QueryDocumentKeys = {
Name: [],
Document: ['definitions'],
OperationDefinition: ['name', 'variableDefinitions', 'directives', 'selectionSet'],
VariableDefinition: ['variable', 'type', 'defaultValue', 'directives'],
Variable: ['name'],
SelectionSet: ['selections'],
Field: ['alias', 'name', 'arguments', 'directives', 'selectionSet'],
Argument: ['name', 'value'],
FragmentSpread: ['name', 'directives'],
InlineFragment: ['typeCondition', 'directives', 'selectionSet'],
FragmentDefinition: ['name', // Note: fragment variable definitions are experimental and may be changed
// or removed in the future.
'variableDefinitions', 'typeCondition', 'directives', 'selectionSet'],
IntValue: [],
FloatValue: [],
StringValue: [],
BooleanValue: [],
NullValue: [],
EnumValue: [],
ListValue: ['values'],
ObjectValue: ['fields'],
ObjectField: ['name', 'value'],
Directive: ['name', 'arguments'],
NamedType: ['name'],
ListType: ['type'],
NonNullType: ['type'],
SchemaDefinition: ['description', 'directives', 'operationTypes'],
OperationTypeDefinition: ['type'],
ScalarTypeDefinition: ['description', 'name', 'directives'],
ObjectTypeDefinition: ['description', 'name', 'interfaces', 'directives', 'fields'],
FieldDefinition: ['description', 'name', 'arguments', 'type', 'directives'],
InputValueDefinition: ['description', 'name', 'type', 'defaultValue', 'directives'],
InterfaceTypeDefinition: ['description', 'name', 'interfaces', 'directives', 'fields'],
UnionTypeDefinition: ['description', 'name', 'directives', 'types'],
EnumTypeDefinition: ['description', 'name', 'directives', 'values'],
EnumValueDefinition: ['description', 'name', 'directives'],
InputObjectTypeDefinition: ['description', 'name', 'directives', 'fields'],
DirectiveDefinition: ['description', 'name', 'arguments', 'locations'],
SchemaExtension: ['directives', 'operationTypes'],
ScalarTypeExtension: ['name', 'directives'],
ObjectTypeExtension: ['name', 'interfaces', 'directives', 'fields'],
InterfaceTypeExtension: ['name', 'interfaces', 'directives', 'fields'],
UnionTypeExtension: ['name', 'directives', 'types'],
EnumTypeExtension: ['name', 'directives', 'values'],
InputObjectTypeExtension: ['name', 'directives', 'fields']
};
export var BREAK = Object.freeze({});
/**
* visit() will walk through an AST using a depth-first traversal, calling
* the visitor's enter function at each node in the traversal, and calling the
* leave function after visiting that node and all of its child nodes.
*
* By returning different values from the enter and leave functions, the
* behavior of the visitor can be altered, including skipping over a sub-tree of
* the AST (by returning false), editing the AST by returning a value or null
* to remove the value, or to stop the whole traversal by returning BREAK.
*
* When using visit() to edit an AST, the original AST will not be modified, and
* a new version of the AST with the changes applied will be returned from the
* visit function.
*
* const editedAST = visit(ast, {
* enter(node, key, parent, path, ancestors) {
* // @return
* // undefined: no action
* // false: skip visiting this node
* // visitor.BREAK: stop visiting altogether
* // null: delete this node
* // any value: replace this node with the returned value
* },
* leave(node, key, parent, path, ancestors) {
* // @return
* // undefined: no action
* // false: no action
* // visitor.BREAK: stop visiting altogether
* // null: delete this node
* // any value: replace this node with the returned value
* }
* });
*
* Alternatively to providing enter() and leave() functions, a visitor can
* instead provide functions named the same as the kinds of AST nodes, or
* enter/leave visitors at a named key, leading to four permutations of the
* visitor API:
*
* 1) Named visitors triggered when entering a node of a specific kind.
*
* visit(ast, {
* Kind(node) {
* // enter the "Kind" node
* }
* })
*
* 2) Named visitors that trigger upon entering and leaving a node of
* a specific kind.
*
* visit(ast, {
* Kind: {
* enter(node) {
* // enter the "Kind" node
* }
* leave(node) {
* // leave the "Kind" node
* }
* }
* })
*
* 3) Generic visitors that trigger upon entering and leaving any node.
*
* visit(ast, {
* enter(node) {
* // enter any node
* },
* leave(node) {
* // leave any node
* }
* })
*
* 4) Parallel visitors for entering and leaving nodes of a specific kind.
*
* visit(ast, {
* enter: {
* Kind(node) {
* // enter the "Kind" node
* }
* },
* leave: {
* Kind(node) {
* // leave the "Kind" node
* }
* }
* })
*/
export function visit(root, visitor) {
var visitorKeys = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : QueryDocumentKeys;
/* eslint-disable no-undef-init */
var stack = undefined;
var inArray = Array.isArray(root);
var keys = [root];
var index = -1;
var edits = [];
var node = undefined;
var key = undefined;
var parent = undefined;
var path = [];
var ancestors = [];
var newRoot = root;
/* eslint-enable no-undef-init */
do {
index++;
var isLeaving = index === keys.length;
var isEdited = isLeaving && edits.length !== 0;
if (isLeaving) {
key = ancestors.length === 0 ? undefined : path[path.length - 1];
node = parent;
parent = ancestors.pop();
if (isEdited) {
if (inArray) {
node = node.slice();
} else {
var clone = {};
for (var _i2 = 0, _Object$keys2 = Object.keys(node); _i2 < _Object$keys2.length; _i2++) {
var k = _Object$keys2[_i2];
clone[k] = node[k];
}
node = clone;
}
var editOffset = 0;
for (var ii = 0; ii < edits.length; ii++) {
var editKey = edits[ii][0];
var editValue = edits[ii][1];
if (inArray) {
editKey -= editOffset;
}
if (inArray && editValue === null) {
node.splice(editKey, 1);
editOffset++;
} else {
node[editKey] = editValue;
}
}
}
index = stack.index;
keys = stack.keys;
edits = stack.edits;
inArray = stack.inArray;
stack = stack.prev;
} else {
key = parent ? inArray ? index : keys[index] : undefined;
node = parent ? parent[key] : newRoot;
if (node === null || node === undefined) {
continue;
}
if (parent) {
path.push(key);
}
}
var result = void 0;
if (!Array.isArray(node)) {
if (!isNode(node)) {
throw new Error("Invalid AST Node: ".concat(inspect(node), "."));
}
var visitFn = getVisitFn(visitor, node.kind, isLeaving);
if (visitFn) {
result = visitFn.call(visitor, node, key, parent, path, ancestors);
if (result === BREAK) {
break;
}
if (result === false) {
if (!isLeaving) {
path.pop();
continue;
}
} else if (result !== undefined) {
edits.push([key, result]);
if (!isLeaving) {
if (isNode(result)) {
node = result;
} else {
path.pop();
continue;
}
}
}
}
}
if (result === undefined && isEdited) {
edits.push([key, node]);
}
if (isLeaving) {
path.pop();
} else {
var _visitorKeys$node$kin;
stack = {
inArray: inArray,
index: index,
keys: keys,
edits: edits,
prev: stack
};
inArray = Array.isArray(node);
keys = inArray ? node : (_visitorKeys$node$kin = visitorKeys[node.kind]) !== null && _visitorKeys$node$kin !== void 0 ? _visitorKeys$node$kin : [];
index = -1;
edits = [];
if (parent) {
ancestors.push(parent);
}
parent = node;
}
} while (stack !== undefined);
if (edits.length !== 0) {
newRoot = edits[edits.length - 1][1];
}
return newRoot;
}
/**
* Creates a new visitor instance which delegates to many visitors to run in
* parallel. Each visitor will be visited for each node before moving on.
*
* If a prior visitor edits a node, no following visitors will see that node.
*/
export function visitInParallel(visitors) {
var skipping = new Array(visitors.length);
return {
enter: function enter(node) {
for (var i = 0; i < visitors.length; i++) {
if (skipping[i] == null) {
var fn = getVisitFn(visitors[i], node.kind,
/* isLeaving */
false);
if (fn) {
var result = fn.apply(visitors[i], arguments);
if (result === false) {
skipping[i] = node;
} else if (result === BREAK) {
skipping[i] = BREAK;
} else if (result !== undefined) {
return result;
}
}
}
}
},
leave: function leave(node) {
for (var i = 0; i < visitors.length; i++) {
if (skipping[i] == null) {
var fn = getVisitFn(visitors[i], node.kind,
/* isLeaving */
true);
if (fn) {
var result = fn.apply(visitors[i], arguments);
if (result === BREAK) {
skipping[i] = BREAK;
} else if (result !== undefined && result !== false) {
return result;
}
}
} else if (skipping[i] === node) {
skipping[i] = null;
}
}
}
};
}
/**
* 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, kind, isLeaving) {
var kindVisitor = visitor[kind];
if (kindVisitor) {
if (!isLeaving && typeof kindVisitor === 'function') {
// { Kind() {} }
return kindVisitor;
}
var kindSpecificVisitor = isLeaving ? kindVisitor.leave : kindVisitor.enter;
if (typeof kindSpecificVisitor === 'function') {
// { Kind: { enter() {}, leave() {} } }
return kindSpecificVisitor;
}
} else {
var specificVisitor = isLeaving ? visitor.leave : visitor.enter;
if (specificVisitor) {
if (typeof specificVisitor === 'function') {
// { enter() {}, leave() {} }
return specificVisitor;
}
var specificKindVisitor = specificVisitor[kind];
if (typeof specificKindVisitor === 'function') {
// { enter: { Kind() {} }, leave: { Kind() {} } }
return specificKindVisitor;
}
}
}
}