fix: flatten nested arrays in parseAbiParameters (#232)

* fix: flatten nested arrays in parseAbiParameters * fix: handle empty array and add type tests * chore: add changeset * chore: update changeset
wevm · Mar 15, 2024 · 22a5f3a · 22a5f3a
1 parent f7d5d15
commit 22a5f3a
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diff --git a/.changeset/cool-buttons-rush.md b/.changeset/cool-buttons-rush.md
@@ -0,0 +1,5 @@
+---
+"abitype": patch
+---
+
+Fixed type detection when using an array in `ParseAbiParameters`
diff --git a/packages/abitype/src/human-readable/parseAbiParameters.test-d.ts b/packages/abitype/src/human-readable/parseAbiParameters.test-d.ts
@@ -109,4 +109,52 @@ test('parseAbiParameters', () => {
   expectTypeOf(parseAbiParameters(param)).toEqualTypeOf<
     readonly AbiParameter[]
   >()
+
+  expectTypeOf(parseAbiParameters(['(uint256 a),(uint256 b)'])).toEqualTypeOf<
+    readonly [
+      {
+        readonly type: 'tuple'
+        readonly components: readonly [
+          {
+            readonly type: 'uint256'
+            readonly name: 'a'
+          },
+        ]
+      },
+      {
+        readonly type: 'tuple'
+        readonly components: readonly [
+          {
+            readonly type: 'uint256'
+            readonly name: 'b'
+          },
+        ]
+      },
+    ]
+  >()
+
+  expectTypeOf(
+    parseAbiParameters(['(uint256 a)', '(uint256 b)']),
+  ).toEqualTypeOf<
+    readonly [
+      {
+        readonly type: 'tuple'
+        readonly components: readonly [
+          {
+            readonly type: 'uint256'
+            readonly name: 'a'
+          },
+        ]
+      },
+      {
+        readonly type: 'tuple'
+        readonly components: readonly [
+          {
+            readonly type: 'uint256'
+            readonly name: 'b'
+          },
+        ]
+      },
+    ]
+  >()
 })
diff --git a/packages/abitype/src/human-readable/parseAbiParameters.ts b/packages/abitype/src/human-readable/parseAbiParameters.ts
@@ -51,15 +51,37 @@ export type ParseAbiParameters<
                   >
               : never
           } extends infer Mapped extends readonly unknown[]
-          ? Filter<Mapped, never>[0] extends infer Result
-            ? Result extends undefined
+          ? Filter<Mapped, never> extends readonly [...infer Content]
+            ? Content['length'] extends 0
               ? never
-              : Result
+              : DeepFlatten<Content>
             : never
           : never
         : never
       : never)
 
+/**
+ * Flatten all members of {@link T}
+ *
+ * @param T - List of items to flatten
+ * @param Acc - The accumulator used while recursing
+ * @returns The flattened array
+ *
+ * @example
+ * type Result = DeepFlatten<[['a', 'b'], [['c']]]>
+ * //   ^? type Result = ['a', 'b', 'c']
+ */
+type DeepFlatten<
+  T extends readonly unknown[],
+  Acc extends readonly unknown[] = readonly [],
+> = T extends readonly [infer Head, ...infer Tail]
+  ? Tail extends undefined
+    ? never
+    : Head extends readonly unknown[]
+    ? DeepFlatten<Tail, readonly [...Acc, ...DeepFlatten<Head>]>
+    : DeepFlatten<Tail, readonly [...Acc, Head]>
+  : Acc
+
 /**
  * Parses human-readable ABI parameters into {@link AbiParameter}s
  *