substrate: add .at() method to generated classes (#324)

common/changes/@subsquid/scale-type-system/is-storage-exists_2024-07-25-20-24.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@subsquid/scale-type-system",
+      "comment": "export more utility types",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@subsquid/scale-type-system"
+}

common/changes/@subsquid/substrate-runtime/is-storage-exists_2024-07-25-20-24.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@subsquid/substrate-runtime",
+      "comment": "add `.hasStorage()` method",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@subsquid/substrate-runtime"
+}

common/changes/@subsquid/substrate-typegen/is-storage-exists_2024-07-25-20-24.json

@@ -0,0 +1,15 @@
+{
+  "changes": [
+    {
+      "packageName": "@subsquid/substrate-typegen",
+      "comment": "add `.at()` method on generated classes",
+      "type": "minor"
+    },
+    {
+      "packageName": "@subsquid/substrate-typegen",
+      "comment": "add `index.ts` to pallet modules",
+      "type": "minor"
+    },
+  ],
+  "packageName": "@subsquid/substrate-typegen"
+}

substrate/scale-type-system/src/dsl.ts

@@ -18,11 +18,11 @@ import {
     UnknownType
 } from './types/primitives'
 import {GetStructType, StructType} from './types/struct'
-import {TupleType} from './types/tuple'
+import {TupleType, GetTupleType} from './types/tuple'
 import {UnionType} from './types/union'
 
 
-export {GetType, ExternalEnum, ValueCase}
+export {GetType, ExternalEnum, ValueCase, GetEnumType, GetTupleType, GetStructType}
 
 
 const numberType = new NumberType()

substrate/scale-type-system/src/types/tuple.ts

@@ -5,9 +5,7 @@ import {BaseType, ScaleType, Type, TypeChecker} from '../type-checker'
 import {GetType} from '../type-util'
 
 
-export type GetTupleType<T> = {
-    [I in keyof T]: GetType<T[I]>
-}
+export type GetTupleType<T> = T extends readonly [infer A, ...infer R] ? [GetType<A>, ...GetTupleType<R>] : []
 
 
 export class TupleType<T extends readonly Type[]> extends BaseType<GetTupleType<T>> {

substrate/substrate-runtime/src/runtime/runtime.ts

@@ -424,6 +424,11 @@ export class Runtime {
         return this.checkType(def.type, ty)
     }
 
+    hasStorage(name: QualifiedName): boolean {
+        let qn = parseQualifiedName(name)
+        return !!this.description.storage[qn[0]]?.items[qn[1]]
+    }
+
     checkStorageType(
         name: QualifiedName,
         modifier: StorageItem['modifier'] | StorageItem['modifier'][],