Scaffold explicit query placement and authored GraphQL documents

src/capability-language/query-scaffold.ts

@@ -0,0 +1,79 @@
+import fs from "node:fs/promises";
+import path from "node:path";
+import { parse } from "graphql";
+import type { ScaffoldRecipe } from "./scaffold-recipes.js";
+import type { StructuralRequest } from "./structural-plan.js";
+import { parseQx, walkSyntax } from "./source.js";
+
+/** Insert the authored query and its document together; placement never changes implicitly. */
+export async function scaffoldQuery(root: string, prefix: string, spec: ScaffoldRecipe): Promise<StructuralRequest> {
+  if (
+    !spec.name ||
+    !/^[A-Za-z_][A-Za-z0-9_]*$/.test(spec.name) ||
+    !spec.id ||
+    !spec.declaration ||
+    typeof spec.queryDocument !== "string"
+  )
+    throw new Error("Query scaffold requires name, id, declaration and queryDocument");
+  const source = `package Draft id "draft" revision "draft@1" { ${spec.declaration} }`;
+  const syntax = parseQx(source);
+  const pkg = syntax.root.children.find((node) => node.kind === "packageResourceDecl");
+  const queries = [...walkSyntax(syntax.root)].filter((node) => node.kind === "packageQuery");
+  const query = queries[0];
+  if (
+    syntax.diagnostics.length ||
+    syntax.root.children.length !== 1 ||
+    !pkg ||
+    queries.length !== 1 ||
+    !query ||
+    pkg.children.filter((node) => node.kind === "packageExport").length !== 1 ||
+    pkg.children.some((node) => !["identifier", "stringLiteral", "packageExport"].includes(node.kind))
+  )
+    throw new Error("Expected one QX query declaration");
+  const identifier = query.children.find((node) => node.kind === "identifier")!;
+  const literals = query.children
+    .filter((node) => node.kind === "stringLiteral")
+    .map((node) => JSON.parse(source.slice(node.start, node.end)) as string);
+  const [id, document, operation] = literals;
+  if (source.slice(identifier.start, identifier.end) !== spec.name || id !== spec.id)
+    throw new Error("Query declaration name/ID must match its registration");
+  if (!document || !/^queries\/(?:[A-Za-z0-9_-]+\/)*[A-Za-z0-9_-]+\.graphql$/.test(document))
+    throw new Error("Query document must be a contained queries/*.graphql path");
+  const graphql = parse(spec.queryDocument);
+  const operations = graphql.definitions.filter((definition) => definition.kind === "OperationDefinition");
+  if (operations.length !== 1 || operations[0]!.operation !== "query" || operations[0]!.name?.value !== operation)
+    throw new Error("GraphQL document must contain the declared named query operation");
+  const authored = await fs.readFile(path.join(root, prefix, "package.qx"), "utf8");
+  const existing = parseQx(authored);
+  const parent = existing.root.children.find((node) => node.kind === "packageResourceDecl");
+  if (existing.diagnostics.length || !parent) throw new Error("Fix package.qx before adding a query");
+  for (const node of parent.children.filter((node) => node.kind === "packageExport").flatMap((node) => node.children)) {
+    const name = node.children.find((child) => child.kind === "identifier");
+    const literal = node.children.find((child) => child.kind === "stringLiteral");
+    if (
+      (name && authored.slice(name.start, name.end) === spec.name) ||
+      (literal && JSON.parse(authored.slice(literal.start, literal.end)) === spec.id)
+    )
+      throw new Error("New query requires a unique name and ID");
+  }
+  const parentID = parent.children.find((node) => node.kind === "stringLiteral")!;
+  return {
+    kind: "package",
+    source: spec.source,
+    resourceRoot: spec.directory,
+    validation: "syntax",
+    files: [
+      {
+        file: prefix + "package.qx",
+        edits: [
+          {
+            operation: "append",
+            parent: { kind: "packageResourceDecl", id: JSON.parse(authored.slice(parentID.start, parentID.end)) },
+            source: spec.declaration,
+          },
+        ],
+      },
+      { file: prefix + document, create: spec.queryDocument },
+    ],
+  };
+}