Implement query execution, scoped RPC enrichment, live collections, and scaffold integration

src/queries.ts

@@ -0,0 +1,82 @@
+import { decodeQxValue, type QxValueType } from "./bindings.js";
+import type { QueryResponse } from "./camino/api_pb.js";
+import type { QxObjectRef } from "./references.js";
+
+export type QxQueryPartial<T> = T extends QxObjectRef
+  ? T
+  : T extends readonly (infer Item)[]
+    ? QxQueryPartial<Item>[]
+    : T extends object
+      ? { [Key in keyof T]?: QxQueryPartial<T[Key]> }
+      : T;
+export type QxQuerySnapshot<T> = {
+  runId: string;
+  sequence: bigint;
+  dataVersion: string;
+  bindingDigest: string;
+  consistency: string;
+  fields: { path: readonly (string | number)[]; status: "pending" | "error"; error?: string }[];
+} & ({ status: "ready"; data: T } | { status: "partial"; data: QxQueryPartial<T> });
+declare const queryTypes: unique symbol;
+/** Generated shape evidence, not permission to run a query. */
+export interface QxQueryDescriptor<Variables, Result, Root extends string = string> {
+  readonly id: string;
+  readonly definitionDigest: string;
+  readonly rootInterfaceRevisionId: Root;
+  readonly variables: QxValueType;
+  readonly output: QxValueType;
+  readonly watch: boolean;
+  readonly [queryTypes]?: (variables: Variables, result: Result) => [Variables, Result];
+}
+
+export function decodeQuerySnapshot<T>(
+  response: QueryResponse,
+  output: QxValueType,
+  runId: string,
+  sequence: bigint,
+): QxQuerySnapshot<T> {
+  if (response.preparationToken || response.residualWindows.length)
+    throw new Error("QUERY_RESULT_UNFINISHED: private preparation is not a query result");
+  const fields = [
+    ...response.pending.map((field) => ({ path: field.path, status: "pending" as const })),
+    ...response.errors.map((field) => ({ path: field.path, status: "error" as const, error: field.error })),
+  ].map((field) => ({
+    ...field,
+    path: field.path.map((part) => {
+      if (part.part.case !== "field" && part.part.case !== "index") throw new Error("QUERY_PATCH_INVALID");
+      return part.part.value;
+    }),
+  }));
+  // Pending/error values are absent, not successful nulls of a scalar type.
+  const shape = structuredClone(output);
+  for (const field of fields) {
+    let cursor = shape;
+    for (const [index, part] of field.path.entries()) {
+      while (cursor.kind === "optional") cursor = cursor.value;
+      const last = index === field.path.length - 1;
+      if (typeof part === "string" && cursor.kind === "record" && cursor.fields[part]) {
+        if (last) cursor.fields[part] = { kind: "optional", value: cursor.fields[part]! };
+        else cursor = cursor.fields[part]!;
+      } else if (typeof part === "number" && cursor.kind === "list") cursor = cursor.value;
+      else throw new Error("QUERY_PATCH_INVALID");
+    }
+  }
+  const data = decodeQxValue(shape, response.value, {}) as Record<string, unknown>;
+  for (const field of fields) {
+    let cursor: unknown = data;
+    for (const [index, part] of field.path.entries()) {
+      if (!cursor || typeof cursor !== "object") throw new Error("QUERY_PATCH_INVALID");
+      if (index === field.path.length - 1) delete (cursor as Record<string | number, unknown>)[part];
+      else cursor = (cursor as Record<string | number, unknown>)[part];
+    }
+  }
+  return {
+    runId,
+    sequence,
+    dataVersion: response.dataVersion,
+    bindingDigest: response.bindingDigest,
+    consistency: response.consistency,
+    fields,
+    ...(fields.length ? { status: "partial", data } : { status: "ready", data }),
+  } as QxQuerySnapshot<T>;
+}