From 59504e1cb49733d00e4d1613cfd712c5d29c7bfb Mon Sep 17 00:00:00 2001
From: Sathya Gunasekaran <gsathya.ceg@gmail.com>
Date: Wed, 6 Sep 2023 14:58:04 +0100
Subject: [PATCH] [hir] Traverse function to capture deps, not just body node

Technically there is a body node created for implicit return expression in a
arrow function, so the existing logic should've worked fine. But there seems to
be a Babel bug, so let's work around it by traversing the function.

Added a test case that captures a dep as a param -- this is currently
unsupported  and also something that would've been ignored before this PR. Added
a failing test to make sure we think about this case when we add support for
default params.
---
 .../src/HIR/BuildHIR.ts                       |  2 +-
 ...ction-with-param-as-captured-dep.expect.md | 29 +++++++++++++++++++
 ...ted-function-with-param-as-captured-dep.ts | 14 +++++++++
 ....md => lambda-return-expression.expect.md} | 19 +++++++++---
 ...ression.ts => lambda-return-expression.ts} |  0
 5 files changed, 59 insertions(+), 5 deletions(-)
 create mode 100644 compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.nested-function-with-param-as-captured-dep.expect.md
 create mode 100644 compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.nested-function-with-param-as-captured-dep.ts
 rename compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/{error.todo-lambda-return-expression.expect.md => lambda-return-expression.expect.md} (52%)
 rename compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/{error.todo-lambda-return-expression.ts => lambda-return-expression.ts} (100%)

diff --git a/compiler/packages/babel-plugin-react-forget/src/HIR/BuildHIR.ts b/compiler/packages/babel-plugin-react-forget/src/HIR/BuildHIR.ts
index 2edcf18e32..ed19e7ed76 100644
--- a/compiler/packages/babel-plugin-react-forget/src/HIR/BuildHIR.ts
+++ b/compiler/packages/babel-plugin-react-forget/src/HIR/BuildHIR.ts
@@ -3058,7 +3058,7 @@ function gatherCapturedDeps(
     }
   }
 
-  fn.get("body").traverse({
+  fn.traverse({
     Expression(path) {
       visit(path);
     },
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.nested-function-with-param-as-captured-dep.expect.md b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.nested-function-with-param-as-captured-dep.expect.md
new file mode 100644
index 0000000000..0390e8e9eb
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.nested-function-with-param-as-captured-dep.expect.md
@@ -0,0 +1,29 @@
+
+## Input
+
+```javascript
+function Foo() {
+  (function t() {
+    let x = {};
+    return function a(x = () => {}) {
+      return x;
+    };
+  })();
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Foo,
+  params: [],
+  isComponent: false,
+};
+
+```
+
+
+## Error
+
+```
+[ReactForget] Todo: (BuildHIR::node.lowerReorderableExpression) Expression type 'ArrowFunctionExpression' cannot be safely reordered (4:4)
+```
+          
+      
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.nested-function-with-param-as-captured-dep.ts b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.nested-function-with-param-as-captured-dep.ts
new file mode 100644
index 0000000000..c01ab3a084
--- /dev/null
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.nested-function-with-param-as-captured-dep.ts
@@ -0,0 +1,14 @@
+function Foo() {
+  (function t() {
+    let x = {};
+    return function a(x = () => {}) {
+      return x;
+    };
+  })();
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: Foo,
+  params: [],
+  isComponent: false,
+};
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.todo-lambda-return-expression.expect.md b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/lambda-return-expression.expect.md
similarity index 52%
rename from compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.todo-lambda-return-expression.expect.md
rename to compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/lambda-return-expression.expect.md
index 42607b8aef..443d69faed 100644
--- a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.todo-lambda-return-expression.expect.md
+++ b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/lambda-return-expression.expect.md
@@ -18,11 +18,22 @@ export const FIXTURE_ENTRYPOINT = {
 
 ```
 
+## Code
 
-## Error
+```javascript
+import { invoke } from "shared-runtime";
+
+function useFoo() {
+  const x = {};
+  const result = invoke(() => x);
+  console.log(result);
+}
+
+export const FIXTURE_ENTRYPOINT = {
+  fn: useFoo,
+  params: [],
+  isComponent: false,
+};
 
 ```
-[ReactForget] Invariant: Expected value for identifier `16` to be initialized. (5:5)
-```
-          
       
\ No newline at end of file
diff --git a/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.todo-lambda-return-expression.ts b/compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/lambda-return-expression.ts
similarity index 100%
rename from compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/error.todo-lambda-return-expression.ts
rename to compiler/packages/babel-plugin-react-forget/src/__tests__/fixtures/compiler/lambda-return-expression.ts