Support nested instruction accounts from IDL (#213)

Fix #210

.changeset/cool-rockets-smash.md

@@ -0,0 +1,5 @@
+---
+"@metaplex-foundation/kinobi": patch
+---
+
+Support nested instruction accounts from IDL

src/idl/IdlInstruction.ts

@@ -2,7 +2,7 @@ import type { IdlType } from './IdlType';
 
 export type IdlInstruction = {
   name: string;
-  accounts: IdlInstructionAccount[];
+  accounts: (IdlInstructionAccount | IdlInstructionNestedAccounts)[];
   args: IdlInstructionArg[];
   defaultOptionalAccounts?: boolean;
   legacyOptionalAccountsStrategy?: boolean;
@@ -21,6 +21,11 @@ export type IdlInstructionAccount = {
   desc?: string;
 };
 
+export type IdlInstructionNestedAccounts = {
+  name: string;
+  accounts: (IdlInstructionAccount | IdlInstructionNestedAccounts)[];
+};
+
 export type IdlInstructionArg = {
   name: string;
   type: IdlType;

src/nodes/InstructionAccountNode.ts

@@ -1,4 +1,4 @@
-import { IdlInstructionAccount } from '../idl';
+import { IdlInstructionAccount, IdlInstructionNestedAccounts } from '../idl';
 import { MainCaseString, PartialExcept, mainCase } from '../shared';
 import { InstructionInputValueNode } from './contextualValueNodes';
 
@@ -50,6 +50,16 @@ export function instructionAccountNode<
   };
 }
 
+export function instructionAccountNodesFromIdl(
+  idl: (IdlInstructionAccount | IdlInstructionNestedAccounts)[]
+): InstructionAccountNode[] {
+  return idl.flatMap((account) =>
+    'accounts' in account
+      ? instructionAccountNodesFromIdl(account.accounts)
+      : [instructionAccountNodeFromIdl(account)]
+  );
+}
+
 export function instructionAccountNodeFromIdl(
   idl: IdlInstructionAccount
 ): InstructionAccountNode {

src/nodes/InstructionNode.ts

@@ -2,7 +2,7 @@ import type { IdlInstruction } from '../idl';
 import { InvalidKinobiTreeError, MainCaseString, mainCase } from '../shared';
 import {
   InstructionAccountNode,
-  instructionAccountNodeFromIdl,
+  instructionAccountNodesFromIdl,
 } from './InstructionAccountNode';
 import {
   InstructionArgumentNode,
@@ -171,9 +171,7 @@ export function instructionNodeFromIdl(
     name,
     idlName,
     docs: idl.docs ?? [],
-    accounts: (idl.accounts ?? []).map((account) =>
-      instructionAccountNodeFromIdl(account)
-    ),
+    accounts: instructionAccountNodesFromIdl(idl.accounts ?? []),
     arguments: dataArguments,
     discriminators,
     optionalAccountStrategy: idl.legacyOptionalAccountsStrategy