@apollo/gateway
Version:
106 lines • 3.44 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.isObjectOfType = exports.applyRewrites = void 0;
const federation_internals_1 = require("@apollo/federation-internals");
const graphql_1 = require("graphql");
const FRAGMENT_PREFIX = '... on ';
function applyRewrites(schema, rewrites, value) {
if (!rewrites) {
return;
}
for (const rewrite of rewrites) {
applyRewrite(schema, rewrite, value);
}
}
exports.applyRewrites = applyRewrites;
function applyRewrite(schema, rewrite, value) {
const splitted = splitPathLastElement(rewrite.path);
if (!splitted) {
return;
}
const [parent, last] = splitted;
const { kind, value: fieldName } = parsePathElement(last);
(0, federation_internals_1.assert)(kind === 'fieldName', () => `Unexpected fragment as last element of ${rewrite.path}`);
applyAtPath(schema, parent, value, rewriteAtPathFunction(rewrite, fieldName));
}
function rewriteAtPathFunction(rewrite, fieldAtPath) {
switch (rewrite.kind) {
case 'ValueSetter':
return (obj) => {
obj[fieldAtPath] = rewrite.setValueTo;
};
case 'KeyRenamer':
return (obj) => {
const objAtPath = obj[fieldAtPath];
if (objAtPath) {
obj[rewrite.renameKeyTo] = obj[fieldAtPath];
obj[fieldAtPath] = undefined;
}
};
}
}
function splitPathLastElement(path) {
if (path.length === 0) {
return undefined;
}
const lastIdx = path.length - 1;
return [path.slice(0, lastIdx), path[lastIdx]];
}
function applyAtPath(schema, path, value, fct) {
if (Array.isArray(value)) {
for (const arrayValue of value) {
applyAtPath(schema, path, arrayValue, fct);
}
return;
}
if (typeof value !== 'object' || value === null) {
return;
}
if (path.length === 0) {
fct(value);
return;
}
const [first, ...rest] = path;
const { kind, value: eltValue } = parsePathElement(first);
switch (kind) {
case 'fieldName':
applyAtPath(schema, rest, value[eltValue], fct);
break;
case 'typeName':
if (isObjectOfType(schema, value, eltValue, true)) {
applyAtPath(schema, rest, value, fct);
}
break;
}
}
function parsePathElement(elt) {
if (elt.startsWith(FRAGMENT_PREFIX)) {
return { kind: 'typeName', value: elt.slice(FRAGMENT_PREFIX.length) };
}
else {
return { kind: 'fieldName', value: elt };
}
}
function isObjectOfType(schema, obj, typeCondition, defaultOnUnknownObjectType = false) {
const objTypename = obj['__typename'];
if (!objTypename) {
return defaultOnUnknownObjectType;
}
if (typeCondition === objTypename) {
return true;
}
const type = schema.getType(objTypename);
if (!type) {
return false;
}
const conditionalType = schema.getType(typeCondition);
if (!conditionalType) {
return false;
}
if ((0, graphql_1.isAbstractType)(conditionalType)) {
return ((0, graphql_1.isObjectType)(type) || (0, graphql_1.isInterfaceType)(type)) && schema.isSubType(conditionalType, type);
}
return false;
}
exports.isObjectOfType = isObjectOfType;
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