feat(core/transform): adds filter

packages/core/src/transform/filter.ts

@@ -0,0 +1,72 @@
+import {
+  QueryService,
+  MutationService,
+  SubscriptionService,
+  AbstractElement,
+  ElementInfo,
+  AbstractCollectionTree
+} from '~/types';
+import { replace } from '~/transform/replace';
+import {
+  isElementTree,
+  isTreeCollection,
+  isElementType,
+  isTypeResponse
+} from '~/inspect';
+
+export type FilterTransformFn<
+  Q extends QueryService = QueryService,
+  M extends MutationService = MutationService,
+  S extends SubscriptionService = SubscriptionService
+> = (element: AbstractElement<Q, M, S>, info: ElementInfo) => boolean;
+
+/**
+ * Performs a traversal, returning a new collection where `Element`s are deleted when `cb` returns false. Inline types cannot be filtered.
+ */
+export function filter<
+  Q extends QueryService,
+  M extends MutationService,
+  S extends SubscriptionService
+>(
+  collection: AbstractCollectionTree<Q, M, S>,
+  cb: FilterTransformFn<Q, M, S>
+): AbstractCollectionTree<Q, M, S> {
+  return replace(collection, (element, info, next) => {
+    if (isElementTree(element)) {
+      if (isTreeCollection(element)) {
+        element = { ...element, types: { ...element.types } };
+        for (const [key, value] of Object.entries(element.types)) {
+          const path = info.path.concat(['types', key]);
+          const route = info.route.concat([key]);
+          if (!cb(value, { path, route })) {
+            delete element.types[key];
+          }
+        }
+      }
+      element = { ...element, services: { ...element.services } };
+      for (const [key, value] of Object.entries(element.services)) {
+        const path = info.path.concat(['services', key]);
+        const route = info.route.concat([key]);
+        if (!cb(value, { path, route })) {
+          delete element.services[key];
+        }
+      }
+    } else if (
+      isElementType(element) &&
+      isTypeResponse(element) &&
+      element.children
+    ) {
+      const children = { ...element.children };
+      for (const [key, value] of Object.entries(children)) {
+        const path = info.path.concat(['children', key]);
+        const route = info.route.concat([key]);
+        if (!cb(value, { path, route })) {
+          delete children[key];
+        }
+      }
+      element = { ...element, children };
+    }
+
+    return next(element);
+  });
+}

packages/core/src/transform/index.ts

@@ -1,3 +1,4 @@
-export * from './replace';
 export * from './normalize';
+export * from './replace';
+export * from './filter';
 export * from './to';