@envelop/core
Version:
This is the core package for Envelop. You can find a complete documentation here: https://github.com/graphql-hive/envelop
77 lines (76 loc) • 2.85 kB
JavaScript
export function withState(pluginFactory) {
const states = {};
function getProp(scope, key) {
return {
get() {
if (!states[scope])
states[scope] = new WeakMap();
let value = states[scope].get(key);
if (!value)
states[scope].set(key, (value = {}));
return value;
},
enumerable: true,
};
}
function getState(payload) {
if (!payload) {
return undefined;
}
let { executionRequest, context, request } = payload;
const state = {};
const defineState = (scope, key) => Object.defineProperty(state, scope, getProp(scope, key));
if (executionRequest) {
defineState('forSubgraphExecution', executionRequest);
// ExecutionRequest can happen outside of any Graphql Operation for Gateway internal usage like Introspection queries.
// We check for `params` to be present, which means it's actually a GraphQL context.
if (executionRequest.context?.params)
context = executionRequest.context;
}
if (context) {
defineState('forOperation', context);
if (context.request)
request = context.request;
}
if (request) {
defineState('forRequest', request);
}
return state;
}
function addStateGetters(src) {
const result = {};
for (const [hookName, hook] of Object.entries(src)) {
if (typeof hook !== 'function') {
result[hookName] = hook;
}
else {
result[hookName] = {
[hook.name](payload, ...args) {
if (payload && (payload.request || payload.context || payload.executionRequest)) {
return hook({
...payload,
get state() {
return getState(payload);
},
}, ...args);
}
else {
return hook(payload, ...args);
}
},
}[hook.name];
}
}
return result;
}
const { instrumentation, ...hooks } = pluginFactory(getState);
const pluginWithState = addStateGetters(hooks);
if (instrumentation) {
pluginWithState.instrumentation = addStateGetters(instrumentation);
}
return pluginWithState;
}
export function getMostSpecificState(state = {}) {
const { forOperation, forRequest, forSubgraphExecution } = state;
return forSubgraphExecution ?? forOperation ?? forRequest;
}