From d1c21e3fcd22a1bacdb5272af21d84ba4c6d47ad Mon Sep 17 00:00:00 2001
From: Ayaz Hafiz <ayaz@rwx.com>
Date: Wed, 17 Aug 2022 17:02:45 -0500
Subject: [PATCH] Add polymorphic expression reproduction cases from #1745

These work now that we have ways to compile polymorphic expressions.

Closes #1745
---
 crates/compiler/test_gen/src/gen_list.rs      | 20 +++++++++++++++++
 .../compiler/test_gen/src/gen_primitives.rs   | 21 ++++++++++++++++++
 crates/compiler/test_gen/src/gen_tags.rs      | 22 +++++++++++++++++++
 3 files changed, 63 insertions(+)

diff --git a/crates/compiler/test_gen/src/gen_list.rs b/crates/compiler/test_gen/src/gen_list.rs
index 057750b461..c3540e619d 100644
--- a/crates/compiler/test_gen/src/gen_list.rs
+++ b/crates/compiler/test_gen/src/gen_list.rs
@@ -3369,3 +3369,23 @@ fn issue_3530_uninitialized_capacity_in_list_literal() {
         |(_, _, cap)| cap
     );
 }
+
+#[test]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
+fn list_let_generalization() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            empty : List a
+            empty = []
+
+            xs : List Str
+            xs = List.append empty "foo"
+
+            List.len xs
+            "#
+        ),
+        1,
+        usize
+    );
+}
diff --git a/crates/compiler/test_gen/src/gen_primitives.rs b/crates/compiler/test_gen/src/gen_primitives.rs
index 8ed0dbc8bb..d986c46c19 100644
--- a/crates/compiler/test_gen/src/gen_primitives.rs
+++ b/crates/compiler/test_gen/src/gen_primitives.rs
@@ -4019,3 +4019,24 @@ fn mutually_recursive_captures() {
         RocStr
     );
 }
+
+#[test]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
+fn int_let_generalization() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            manyAux : {} -> I32 
+            manyAux = \_ ->
+                output = \_ -> 42
+
+                output {}
+
+            when manyAux {} is
+                _ -> "done"
+            "#
+        ),
+        RocStr::from("done"),
+        RocStr
+    );
+}
diff --git a/crates/compiler/test_gen/src/gen_tags.rs b/crates/compiler/test_gen/src/gen_tags.rs
index 2cad1617f8..6eccdd3bd1 100644
--- a/crates/compiler/test_gen/src/gen_tags.rs
+++ b/crates/compiler/test_gen/src/gen_tags.rs
@@ -1933,3 +1933,25 @@ fn issue_2165_recursive_tag_destructure() {
         RocStr
     )
 }
+
+#[test]
+#[cfg(any(feature = "gen-llvm", feature = "gen-wasm"))]
+fn tag_union_let_generalization() {
+    assert_evals_to!(
+        indoc!(
+            r#"
+            manyAux : {} -> [ Loop, Done ]
+            manyAux = \_ ->
+                output = Done
+
+                output
+
+            when manyAux {} is
+                Loop -> "loop"
+                Done -> "done"
+            "#
+        ),
+        RocStr::from("done"),
+        RocStr
+    );
+}