四好公路
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"use strict";
module.exports = $Ref;
const Pointer = require("./pointer");
const { InvalidPointerError, isHandledError, normalizeError } = require("./util/errors");
const { safePointerToPath, stripHash, getHash } = require("./util/url");
/**
* This class represents a single JSON reference and its resolved value.
*
* @class
*/
function $Ref () {
/**
* The file path or URL of the referenced file.
* This path is relative to the path of the main JSON schema file.
*
* This path does NOT contain document fragments (JSON pointers). It always references an ENTIRE file.
* Use methods such as {@link $Ref#get}, {@link $Ref#resolve}, and {@link $Ref#exists} to get
* specific JSON pointers within the file.
*
* @type {string}
*/
this.path = undefined;
/**
* The resolved value of the JSON reference.
* Can be any JSON type, not just objects. Unknown file types are represented as Buffers (byte arrays).
*
* @type {?*}
*/
this.value = undefined;
/**
* The {@link $Refs} object that contains this {@link $Ref} object.
*
* @type {$Refs}
*/
this.$refs = undefined;
/**
* Indicates the type of {@link $Ref#path} (e.g. "file", "http", etc.)
*
* @type {?string}
*/
this.pathType = undefined;
/**
* List of all errors. Undefined if no errors.
*
* @type {Array<JSONParserError | ResolverError | ParserError | MissingPointerError>}
*/
this.errors = undefined;
}
/**
* Pushes an error to errors array.
*
* @param {Array<JSONParserError | JSONParserErrorGroup>} err - The error to be pushed
* @returns {void}
*/
$Ref.prototype.addError = function (err) {
if (this.errors === undefined) {
this.errors = [];
}
const existingErrors = this.errors.map(({ footprint }) => footprint);
// the path has been almost certainly set at this point,
// but just in case something went wrong, normalizeError injects path if necessary
// moreover, certain errors might point at the same spot, so filter them out to reduce noise
if (Array.isArray(err.errors)) {
this.errors.push(...err.errors
.map(normalizeError)
.filter(({ footprint }) => !existingErrors.includes(footprint)),
);
}
else if (!existingErrors.includes(err.footprint)) {
this.errors.push(normalizeError(err));
}
};
/**
* Determines whether the given JSON reference exists within this {@link $Ref#value}.
*
* @param {string} path - The full path being resolved, optionally with a JSON pointer in the hash
* @param {$RefParserOptions} options
* @returns {boolean}
*/
$Ref.prototype.exists = function (path, options) {
try {
this.resolve(path, options);
return true;
}
catch (e) {
return false;
}
};
/**
* Resolves the given JSON reference within this {@link $Ref#value} and returns the resolved value.
*
* @param {string} path - The full path being resolved, optionally with a JSON pointer in the hash
* @param {$RefParserOptions} options
* @returns {*} - Returns the resolved value
*/
$Ref.prototype.get = function (path, options) {
return this.resolve(path, options).value;
};
/**
* Resolves the given JSON reference within this {@link $Ref#value}.
*
* @param {string} path - The full path being resolved, optionally with a JSON pointer in the hash
* @param {$RefParserOptions} options
* @param {string} friendlyPath - The original user-specified path (used for error messages)
* @param {string} pathFromRoot - The path of `obj` from the schema root
* @returns {Pointer | null}
*/
$Ref.prototype.resolve = function (path, options, friendlyPath, pathFromRoot) {
let pointer = new Pointer(this, path, friendlyPath);
try {
return pointer.resolve(this.value, options, pathFromRoot);
}
catch (err) {
if (!options || !options.continueOnError || !isHandledError(err)) {
throw err;
}
if (err.path === null) {
err.path = safePointerToPath(getHash(pathFromRoot));
}
if (err instanceof InvalidPointerError) {
// this is a special case - InvalidPointerError is thrown when dereferencing external file,
// but the issue is caused by the source file that referenced the file that undergoes dereferencing
err.source = stripHash(pathFromRoot);
}
this.addError(err);
return null;
}
};
/**
* Sets the value of a nested property within this {@link $Ref#value}.
* If the property, or any of its parents don't exist, they will be created.
*
* @param {string} path - The full path of the property to set, optionally with a JSON pointer in the hash
* @param {*} value - The value to assign
*/
$Ref.prototype.set = function (path, value) {
let pointer = new Pointer(this, path);
this.value = pointer.set(this.value, value);
};
/**
* Determines whether the given value is a JSON reference.
*
* @param {*} value - The value to inspect
* @returns {boolean}
*/
$Ref.is$Ref = function (value) {
return value && typeof value === "object" && typeof value.$ref === "string" && value.$ref.length > 0;
};
/**
* Determines whether the given value is an external JSON reference.
*
* @param {*} value - The value to inspect
* @returns {boolean}
*/
$Ref.isExternal$Ref = function (value) {
return $Ref.is$Ref(value) && value.$ref[0] !== "#";
};
/**
* Determines whether the given value is a JSON reference, and whether it is allowed by the options.
* For example, if it references an external file, then options.resolve.external must be true.
*
* @param {*} value - The value to inspect
* @param {$RefParserOptions} options
* @returns {boolean}
*/
$Ref.isAllowed$Ref = function (value, options) {
if ($Ref.is$Ref(value)) {
if (value.$ref.substr(0, 2) === "#/" || value.$ref === "#") {
// It's a JSON Pointer reference, which is always allowed
return true;
}
else if (value.$ref[0] !== "#" && (!options || options.resolve.external)) {
// It's an external reference, which is allowed by the options
return true;
}
}
};
/**
* Determines whether the given value is a JSON reference that "extends" its resolved value.
* That is, it has extra properties (in addition to "$ref"), so rather than simply pointing to
* an existing value, this $ref actually creates a NEW value that is a shallow copy of the resolved
* value, plus the extra properties.
*
* @example:
* {
* person: {
* properties: {
* firstName: { type: string }
* lastName: { type: string }
* }
* }
* employee: {
* properties: {
* $ref: #/person/properties
* salary: { type: number }
* }
* }
* }
*
* In this example, "employee" is an extended $ref, since it extends "person" with an additional
* property (salary). The result is a NEW value that looks like this:
*
* {
* properties: {
* firstName: { type: string }
* lastName: { type: string }
* salary: { type: number }
* }
* }
*
* @param {*} value - The value to inspect
* @returns {boolean}
*/
$Ref.isExtended$Ref = function (value) {
return $Ref.is$Ref(value) && Object.keys(value).length > 1;
};
/**
* Returns the resolved value of a JSON Reference.
* If necessary, the resolved value is merged with the JSON Reference to create a new object
*
* @example:
* {
* person: {
* properties: {
* firstName: { type: string }
* lastName: { type: string }
* }
* }
* employee: {
* properties: {
* $ref: #/person/properties
* salary: { type: number }
* }
* }
* }
*
* When "person" and "employee" are merged, you end up with the following object:
*
* {
* properties: {
* firstName: { type: string }
* lastName: { type: string }
* salary: { type: number }
* }
* }
*
* @param {object} $ref - The JSON reference object (the one with the "$ref" property)
* @param {*} resolvedValue - The resolved value, which can be any type
* @returns {*} - Returns the dereferenced value
*/
$Ref.dereference = function ($ref, resolvedValue) {
if (resolvedValue && typeof resolvedValue === "object" && $Ref.isExtended$Ref($ref)) {
let merged = {};
for (let key of Object.keys($ref)) {
if (key !== "$ref") {
merged[key] = $ref[key];
}
}
for (let key of Object.keys(resolvedValue)) {
if (!(key in merged)) {
merged[key] = resolvedValue[key];
}
}
return merged;
}
else {
// Completely replace the original reference with the resolved value
return resolvedValue;
}
};