Expect no longer crashes

compiler/builtins/bitcode/src/utils.zig

@@ -25,6 +25,9 @@ comptime {
         @export(testing_roc_realloc, .{ .name = "roc_realloc", .linkage = .Strong });
         @export(testing_roc_dealloc, .{ .name = "roc_dealloc", .linkage = .Strong });
         @export(testing_roc_panic, .{ .name = "roc_panic", .linkage = .Strong });
+        @export(testing_roc_expect_failed, .{ .name = "roc_expect_failed", .linkage = .Strong });
+    } else {
+        @export(expect_failed, .{ .name = "roc_expect_failed", .linkage = .Strong });
     }
 }
 
@@ -45,6 +48,16 @@ fn testing_roc_dealloc(c_ptr: *c_void, _: u32) callconv(.C) void {
     std.testing.allocator.destroy(ptr);
 }
 
+fn testing_roc_expect_failed() callconv(.C) void {
+    const stderr = std.io.getStdErr().writer();
+    stderr.print("Expect failed inside test\n", .{}) catch unreachable;
+}
+
+fn expect_failed() callconv(.C) void {
+    const stderr = std.io.getStdErr().writer();
+    stderr.print("Expect failed outside test\n", .{}) catch unreachable;
+}
+
 fn testing_roc_panic(c_ptr: *c_void, tag_id: u32) callconv(.C) void {
     _ = c_ptr;
     _ = tag_id;

compiler/builtins/src/bitcode.rs

@@ -82,3 +82,4 @@ pub const DEC_MUL_WITH_OVERFLOW: &str = "roc_builtins.dec.mul_with_overflow";
 pub const DEC_DIV: &str = "roc_builtins.dec.div";
 
 pub const UTILS_TEST_PANIC: &str = "roc_builtins.utils.test_panic";
+pub const EXPECT_FAILED: &str = "roc_expect_failed";

compiler/gen_llvm/src/llvm/build.rs

@@ -5175,8 +5175,9 @@ fn run_low_level<'a, 'ctx, 'env>(
 
             bd.position_at_end(throw_block);
 
-            throw_exception(env, "assert failed!");
+            call_void_bitcode_fn(env, &[], bitcode::EXPECT_FAILED);
 
+            bd.build_unconditional_branch(then_block);
             bd.position_at_end(then_block);
 
             cond

compiler/test_gen/src/gen_primitives.rs

@@ -2398,7 +2398,7 @@ fn call_invalid_layout() {
 }
 
 #[test]
-#[should_panic(expected = "assert failed!")]
+// #[should_panic(expected = "assert failed!")]
 fn expect_fail() {
     assert_evals_to!(
         indoc!(