From 46b1b8fae46b08e0fe0217aea1fd98c1beb98905 Mon Sep 17 00:00:00 2001
From: Tadeo Hepperle <62739623+tadeohepperle@users.noreply.github.com>
Date: Wed, 17 Jan 2024 13:38:38 +0100
Subject: [PATCH] Introduce more solid `no_std` testing (#199)

* introduce more solid no-std tests

* clippy fix bc of new rust version

* include scale and bitvec in no std tests
---
 .github/workflows/rust.yml                    |  5 +-
 src/portable.rs                               |  2 +-
 test_suite/derive_tests_no_std/Cargo.toml     | 13 +++--
 test_suite/derive_tests_no_std/rust-toolchain |  1 +
 test_suite/derive_tests_no_std/src/main.rs    | 54 +++++++++++++++----
 5 files changed, 61 insertions(+), 14 deletions(-)
 create mode 100644 test_suite/derive_tests_no_std/rust-toolchain

diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 488b505e..409adcef 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -55,7 +55,10 @@ jobs:
       run: |
         cargo test --all --all-features
 
+    # We cannot do usual rust tests in `no_std`. Instead we perform tests in the main function.
+    # If any assert fails, we get an `Aborted (core dumped)` non-zero exit code.
+    # This should make the CI fail.
     - name: test no-std
       run: |
         cd ./test_suite/derive_tests_no_std
-        cargo build --no-default-features
+        cargo run --no-default-features
diff --git a/src/portable.rs b/src/portable.rs
index e9bc1da4..c19bb7ec 100644
--- a/src/portable.rs
+++ b/src/portable.rs
@@ -118,7 +118,7 @@ impl PortableRegistry {
             for param in ty.ty.type_params.iter_mut() {
                 let Some(ty) = &param.ty else { continue };
                 let new_id = retain_type(ty.id, types, new_types, retained_mappings);
-                param.ty = Some(new_id).map(Into::into);
+                param.ty = Some(Into::into(new_id));
             }
 
             // make sure any types inside this type are also retained and update the IDs:
diff --git a/test_suite/derive_tests_no_std/Cargo.toml b/test_suite/derive_tests_no_std/Cargo.toml
index 820c0efe..5f99b236 100644
--- a/test_suite/derive_tests_no_std/Cargo.toml
+++ b/test_suite/derive_tests_no_std/Cargo.toml
@@ -10,9 +10,16 @@ license = "Apache-2.0"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-scale-info = { path = "../..", default-features = false, features = ["derive"] }
-scale = { package = "parity-scale-codec", version = "2", features = ["full"] }
-
+scale-info = { path = "../..", default-features = false, features = ["derive", "bit-vec", "decode"] }
+scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive", "bit-vec"] }
+bitvec = { version = "1", default-features = false, features = ["alloc"] }
 libc = { version = "0.2", default-features = false }
+libc_alloc = { version = "1.0.6" }
+
+[profile.dev]
+panic = "abort"
+
+[profile.release]
+panic = "abort"
 
 [workspace]
diff --git a/test_suite/derive_tests_no_std/rust-toolchain b/test_suite/derive_tests_no_std/rust-toolchain
new file mode 100644
index 00000000..07ade694
--- /dev/null
+++ b/test_suite/derive_tests_no_std/rust-toolchain
@@ -0,0 +1 @@
+nightly
\ No newline at end of file
diff --git a/test_suite/derive_tests_no_std/src/main.rs b/test_suite/derive_tests_no_std/src/main.rs
index e8a8fa0e..b1bfff08 100644
--- a/test_suite/derive_tests_no_std/src/main.rs
+++ b/test_suite/derive_tests_no_std/src/main.rs
@@ -12,27 +12,66 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
-
+#![allow(internal_features)]
+#![feature(lang_items, start)]
+#![feature(alloc_error_handler)]
 #![no_std]
 
+#[start]
+fn start(_argc: isize, _argv: *const *const u8) -> isize {
+    test();
+    0
+}
+
+#[lang = "eh_personality"]
+#[no_mangle]
+pub extern "C" fn rust_eh_personality() {}
+
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    unsafe {
+        libc::abort();
+    }
+}
+
+use libc_alloc::LibcAlloc;
+
+#[global_allocator]
+static ALLOCATOR: LibcAlloc = LibcAlloc;
+
+//////////////////////////////////////////////////////////////////////////////
+
+// Note: Use the types in some way to make sure they are not pruned as dead code.
+// If an assert fails we will get `Aborted (core dumped)`.
+fn test() {
+    assert_eq!(UnitStruct::type_info().type_params.len(), 0);
+    assert_eq!(TupleStruct::type_info().type_params.len(), 0);
+    assert_eq!(Struct::<TupleStruct>::type_info().type_params.len(), 1);
+    assert_eq!(CLike::type_info().type_params.len(), 0);
+    assert_eq!(E::<CLike>::type_info().type_params.len(), 1);
+}
+
+use bitvec::{order::Lsb0, vec::BitVec};
+use scale::{Decode, Encode};
 use scale_info::TypeInfo;
 
 #[allow(unused)]
-#[derive(TypeInfo)]
+#[derive(TypeInfo, Decode, Encode)]
 struct UnitStruct;
 
 #[allow(unused)]
-#[derive(TypeInfo)]
+#[derive(TypeInfo, Decode, Encode)]
 struct TupleStruct(u128, bool);
 
 #[allow(unused)]
-#[derive(TypeInfo)]
+#[derive(TypeInfo, Decode, Encode)]
 struct Struct<T> {
     t: T,
+    bitvec: BitVec<u16, Lsb0>,
 }
 
 #[allow(unused)]
-#[derive(TypeInfo)]
+#[derive(TypeInfo, Decode, Encode)]
 enum CLike {
     A,
     B,
@@ -40,12 +79,9 @@ enum CLike {
 }
 
 #[allow(unused)]
-#[derive(TypeInfo)]
+#[derive(TypeInfo, Decode, Encode)]
 enum E<T> {
     A(T),
     B { b: T },
     C,
 }
-
-fn main() {
-}