| import { Kind } from '../language/kinds.mjs'; |
| import { visit } from '../language/visitor.mjs'; |
| /** |
| * separateOperations accepts a single AST document which may contain many |
| * operations and fragments and returns a collection of AST documents each of |
| * which contains a single operation as well the fragment definitions it |
| * refers to. |
| */ |
| |
| export function separateOperations(documentAST) { |
| const operations = []; |
| const depGraph = Object.create(null); // Populate metadata and build a dependency graph. |
| |
| for (const definitionNode of documentAST.definitions) { |
| switch (definitionNode.kind) { |
| case Kind.OPERATION_DEFINITION: |
| operations.push(definitionNode); |
| break; |
| |
| case Kind.FRAGMENT_DEFINITION: |
| depGraph[definitionNode.name.value] = collectDependencies( |
| definitionNode.selectionSet, |
| ); |
| break; |
| |
| default: // ignore non-executable definitions |
| } |
| } // For each operation, produce a new synthesized AST which includes only what |
| // is necessary for completing that operation. |
| |
| const separatedDocumentASTs = Object.create(null); |
| |
| for (const operation of operations) { |
| const dependencies = new Set(); |
| |
| for (const fragmentName of collectDependencies(operation.selectionSet)) { |
| collectTransitiveDependencies(dependencies, depGraph, fragmentName); |
| } // Provides the empty string for anonymous operations. |
| |
| const operationName = operation.name ? operation.name.value : ''; // The list of definition nodes to be included for this operation, sorted |
| // to retain the same order as the original document. |
| |
| separatedDocumentASTs[operationName] = { |
| kind: Kind.DOCUMENT, |
| definitions: documentAST.definitions.filter( |
| (node) => |
| node === operation || |
| (node.kind === Kind.FRAGMENT_DEFINITION && |
| dependencies.has(node.name.value)), |
| ), |
| }; |
| } |
| |
| return separatedDocumentASTs; |
| } |
| |
| // From a dependency graph, collects a list of transitive dependencies by |
| // recursing through a dependency graph. |
| function collectTransitiveDependencies(collected, depGraph, fromName) { |
| if (!collected.has(fromName)) { |
| collected.add(fromName); |
| const immediateDeps = depGraph[fromName]; |
| |
| if (immediateDeps !== undefined) { |
| for (const toName of immediateDeps) { |
| collectTransitiveDependencies(collected, depGraph, toName); |
| } |
| } |
| } |
| } |
| |
| function collectDependencies(selectionSet) { |
| const dependencies = []; |
| visit(selectionSet, { |
| FragmentSpread(node) { |
| dependencies.push(node.name.value); |
| }, |
| }); |
| return dependencies; |
| } |