From 5bc2c807c39cb38fc9ae8acaa69fb96fd3d2b393 Mon Sep 17 00:00:00 2001
From: Joe Savona <joesavona@fb.com>
Date: Wed, 15 Mar 2023 15:33:14 -0700
Subject: [PATCH] Support array pattern params

---
 compiler/forget/src/HIR/BuildHIR.ts           |  2 +-
 .../compiler/array-pattern-params.expect.md   | 54 +++++++++++++++++++
 .../fixtures/compiler/array-pattern-params.js |  5 ++
 .../compiler/error.todo-kitchensink.expect.md | 16 ------
 4 files changed, 60 insertions(+), 17 deletions(-)
 create mode 100644 compiler/forget/src/__tests__/fixtures/compiler/array-pattern-params.expect.md
 create mode 100644 compiler/forget/src/__tests__/fixtures/compiler/array-pattern-params.js

diff --git a/compiler/forget/src/HIR/BuildHIR.ts b/compiler/forget/src/HIR/BuildHIR.ts
index d77b7db19a..d1b2ffbc21 100644
--- a/compiler/forget/src/HIR/BuildHIR.ts
+++ b/compiler/forget/src/HIR/BuildHIR.ts
@@ -102,7 +102,7 @@ export function lower(
         loc: param.node.loc ?? GeneratedSource,
       };
       params.push(place);
-    } else if (param.isObjectPattern()) {
+    } else if (param.isObjectPattern() || param.isArrayPattern()) {
       const place: Place = {
         kind: "Identifier",
         identifier: builder.makeTemporary(),
diff --git a/compiler/forget/src/__tests__/fixtures/compiler/array-pattern-params.expect.md b/compiler/forget/src/__tests__/fixtures/compiler/array-pattern-params.expect.md
new file mode 100644
index 0000000000..e9e0b009e0
--- /dev/null
+++ b/compiler/forget/src/__tests__/fixtures/compiler/array-pattern-params.expect.md
@@ -0,0 +1,54 @@
+
+## Input
+
+```javascript
+function component([a, b]) {
+  let y = { a };
+  let z = { b };
+  return [y, z];
+}
+
+```
+
+## Code
+
+```javascript
+function component(t16) {
+  const $ = React.unstable_useMemoCache(7);
+  const [a, b] = t16;
+  const c_0 = $[0] !== a;
+  let t0;
+  if (c_0) {
+    t0 = { a };
+    $[0] = a;
+    $[1] = t0;
+  } else {
+    t0 = $[1];
+  }
+  const y = t0;
+  const c_2 = $[2] !== b;
+  let t1;
+  if (c_2) {
+    t1 = { b };
+    $[2] = b;
+    $[3] = t1;
+  } else {
+    t1 = $[3];
+  }
+  const z = t1;
+  const c_4 = $[4] !== y;
+  const c_5 = $[5] !== z;
+  let t2;
+  if (c_4 || c_5) {
+    t2 = [y, z];
+    $[4] = y;
+    $[5] = z;
+    $[6] = t2;
+  } else {
+    t2 = $[6];
+  }
+  return t2;
+}
+
+```
+      
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/compiler/array-pattern-params.js b/compiler/forget/src/__tests__/fixtures/compiler/array-pattern-params.js
new file mode 100644
index 0000000000..5444d98405
--- /dev/null
+++ b/compiler/forget/src/__tests__/fixtures/compiler/array-pattern-params.js
@@ -0,0 +1,5 @@
+function component([a, b]) {
+  let y = { a };
+  let z = { b };
+  return [y, z];
+}
diff --git a/compiler/forget/src/__tests__/fixtures/compiler/error.todo-kitchensink.expect.md b/compiler/forget/src/__tests__/fixtures/compiler/error.todo-kitchensink.expect.md
index 33b4d0eeb0..6f29931579 100644
--- a/compiler/forget/src/__tests__/fixtures/compiler/error.todo-kitchensink.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/compiler/error.todo-kitchensink.expect.md
@@ -83,13 +83,6 @@ let moduleLocal = false;
 ## Error
 
 ```
-[ReactForget] TodoError: (BuildHIR::lower) Handle ArrayPattern params
-> 1 | function foo([a, b], { c, d, e = "e" }, f = "f", ...args) {
-    |              ^^^^^^
-  2 |   let i = 0;
-  3 |   var x = [];
-  4 |
-
 [ReactForget] TodoError: (BuildHIR::lowerAssignment) Handle AssignmentPattern assignments
 > 1 | function foo([a, b], { c, d, e = "e" }, f = "f", ...args) {
     |                              ^^^^^^^
@@ -192,15 +185,6 @@ let moduleLocal = false;
   22 |   const j = function bar([quz, qux], ...args) {};
   23 |
 
-[ReactForget] TodoError: (BuildHIR::lower) Handle ArrayPattern params
-  20 |   <DesignSystem.Button />;
-  21 |
-> 22 |   const j = function bar([quz, qux], ...args) {};
-     |                          ^^^^^^^^^^
-  23 |
-  24 |   for (; i < 3; i += 1) {
-  25 |     x.push(i);
-
 [ReactForget] TodoError: (BuildHIR::lower) Handle RestElement params
   20 |   <DesignSystem.Button />;
   21 |