Files
30-seconds-of-code/node_modules/graphql-compose/mjs/utils/projection.mjs
2019-08-20 15:52:05 +02:00

105 lines
3.1 KiB
JavaScript

/* eslint-disable no-param-reassign, no-lonely-if */
import { Kind, GraphQLObjectType, GraphQLList, GraphQLNonNull, GraphQLInterfaceType } from '../graphql';
import deepmerge from './deepmerge';
const {
FIELD,
FRAGMENT_SPREAD,
INLINE_FRAGMENT
} = Kind; // export type ProjectionType = { [fieldName: string]: $Shape<ProjectionNode> | true };
// export type ProjectionNode = { [fieldName: string]: $Shape<ProjectionNode> } | true;
export function getProjectionFromAST(info, fieldNode) {
if (!info) {
return {};
}
const queryProjection = getProjectionFromASTquery(info, fieldNode);
const queryExtProjection = extendByFieldProjection(info.returnType, queryProjection);
return queryExtProjection;
}
export function getProjectionFromASTquery(info, fieldNode) {
if (!info) {
return {};
}
let selections; // Array<FieldNode | InlineFragmentNode | FragmentSpreadNode>;
if (fieldNode) {
if (fieldNode.selectionSet) {
selections = fieldNode.selectionSet.selections;
}
} else if (Array.isArray(info.fieldNodes)) {
// get all selectionSets
selections = info.fieldNodes.reduce((result, source) => {
if (source.selectionSet) {
result.push(...source.selectionSet.selections);
}
return result;
}, []);
}
const projection = (selections || []).reduce((res, ast) => {
switch (ast.kind) {
case FIELD:
{
const {
value
} = ast.name;
if (res[value]) {
res[value] = deepmerge(res[value], getProjectionFromASTquery(info, ast) || true);
} else {
res[value] = getProjectionFromASTquery(info, ast) || true;
}
return res;
}
case INLINE_FRAGMENT:
return deepmerge(res, getProjectionFromASTquery(info, ast));
case FRAGMENT_SPREAD:
return deepmerge(res, getProjectionFromASTquery(info, info.fragments[ast.name.value]));
default:
throw new Error('Unsuported query selection');
}
}, {});
return projection;
}
export function getFlatProjectionFromAST(info, fieldNodes) {
const projection = getProjectionFromAST(info, fieldNodes) || {};
const flatProjection = {};
Object.keys(projection).forEach(key => {
flatProjection[key] = !!projection[key];
});
return flatProjection;
} // This method traverse fields and extends current projection
// by projection from fields
export function extendByFieldProjection(returnType, projection) {
let type = returnType;
while (type instanceof GraphQLList || type instanceof GraphQLNonNull) {
type = type.ofType;
}
if (!(type instanceof GraphQLObjectType || type instanceof GraphQLInterfaceType)) {
return projection;
}
let proj = projection;
Object.keys(proj).forEach(key => {
const field = type._fields[key];
if (!field) return;
if (field.projection) proj = deepmerge(proj, field.projection);
if (field.extensions && field.extensions.projection) {
proj = deepmerge(proj, field.extensions.projection);
}
proj[key] = extendByFieldProjection(field.type, proj[key]);
});
return proj;
}