Add test of never type in arrays

test/src/e2e_vm_tests/test_programs/should_fail/unify_never/Forc.lock

@@ -0,0 +1,13 @@
+[[package]]
+name = "core"
+source = "path+from-root-DFCFC85C94C0C9BD"
+
+[[package]]
+name = "std"
+source = "path+from-root-DFCFC85C94C0C9BD"
+dependencies = ["core"]
+
+[[package]]
+name = "unify_never"
+source = "member"
+dependencies = ["std"]

test/src/e2e_vm_tests/test_programs/should_fail/unify_never/Forc.toml

@@ -0,0 +1,8 @@
+[project]
+authors = ["Fuel Labs <contact@fuel.sh>"]
+license = "Apache-2.0"
+name = "unify_never"
+entry = "main.sw"
+
+[dependencies]
+std = { path = "../../../reduced_std_libs/sway-lib-std-assert" }

test/src/e2e_vm_tests/test_programs/should_fail/unify_never/src/main.sw

@@ -0,0 +1,22 @@
+script;
+
+// Test of unification of the Never type
+
+impl [u32;0] {
+    fn foo(self){
+        log("32");
+    }
+}
+
+impl [!;0] {
+    fn foo(self){
+        log("never");
+    }
+}
+
+fn main() {
+    let z:[u32;0] = [];
+
+    // Should fail because z gets the type of its type ascription
+    let y: [!;0] = z;
+}

test/src/e2e_vm_tests/test_programs/should_fail/unify_never/test.toml

@@ -0,0 +1,9 @@
+category = "fail"
+
+#check: $()error
+#check: $()Mismatched types
+#nextln: $()expected: [!; 0]
+#nextln: $()found:    [u32; 0].
+#nextln: $()help: Variable declaration's type annotation does not match up with the assigned expression's type
+
+#check: $()Aborting due to 1 error

test/src/e2e_vm_tests/test_programs/should_pass/language/unify_never/src/main.sw

@@ -13,7 +13,22 @@ fn test_2(){
 }
 
 
-fn main() {
+impl [u32;0] {
+    fn foo(self) -> u64 {
+        32
+    }
+}
+
+impl [!;0] {
+    fn foo(self) -> u64{
+        64
+    }
+}
+
+fn main() -> u64 {
     test_1();
     test_2();
+
+    let x:[u32;0] = [];
+    x.foo() // should return 32
 }

test/src/e2e_vm_tests/test_programs/should_pass/language/unify_never/test.toml

@@ -1,2 +1,5 @@
-category = "compile"
+category = "run"
 expected_warnings = 1
+expected_result = { action = "return", value = 32 }
+expected_result_new_encoding = { action = "return_data", value = "0000000000000020" }
+validate_abi = false