Replace default off-chain engine with experimental one, remove old one

.gitlab-ci.yml

@@ -257,12 +257,6 @@ test:
     - cargo test --verbose --all-features --no-fail-fast --workspace
     - cargo test --verbose --all-features --no-fail-fast --workspace --doc
 
-      # Just needed as long as we have the `ink-experimental-engine` feature.
-      # We do not invoke `--all-features` here -- this would imply the feature
-      # `ink-experimental-engine`. So in order to still run the tests without the
-      # experimental engine feature we need this command.
-    - cargo test --verbose --features std --no-fail-fast --workspace
-
 docs:
   stage:                           workspace
   <<:                              *docker-env
@@ -318,11 +312,6 @@ codecov:
     # RUSTFLAGS are the cause target cache can't be used here
     - cargo build --verbose --all-features --workspace
     - cargo test --verbose --all-features --no-fail-fast --workspace
-    # Just needed as long as we have the `ink-experimental-engine` feature.
-    # We must additionally run the coverage without `--all-features` here -- this
-    # would imply the feature `ink-experimental-engine`. So in order to still run
-    # the tests without the experimental engine feature we need this command.
-    - cargo test --verbose --features std --no-fail-fast --workspace
     # coverage with branches
     - grcov . --binary-path ./target/debug/ --source-dir . --output-type lcov --llvm --branch
         --ignore-not-existing --ignore "/*" --ignore "tests/*" --output-path lcov-w-branch.info
@@ -352,22 +341,6 @@ examples-test:
         cargo test --verbose --manifest-path examples/delegator/${contract}/Cargo.toml;
       done
 
-examples-test-experimental-engine:
-  stage:                           examples
-  <<:                              *docker-env
-  <<:                              *test-refs
-  needs:
-    - job:                         clippy-std
-      artifacts:                   false
-  script:
-    # We test only the examples for which the tests have already been migrated to
-    # use the experimental engine.
-    - cargo test --no-default-features --features std, ink-experimental-engine --verbose --manifest-path examples/erc20/Cargo.toml
-    - cargo test --no-default-features --features std, ink-experimental-engine --verbose --manifest-path examples/erc1155/Cargo.toml
-    - cargo test --no-default-features --features std, ink-experimental-engine --verbose --manifest-path examples/contract-terminate/Cargo.toml
-    - cargo test --no-default-features --features std, ink-experimental-engine --verbose --manifest-path examples/contract-transfer/Cargo.toml
-
-
 examples-contract-build:
   stage:                           examples
   <<:                              *docker-env

crates/engine/Cargo.toml

@@ -9,7 +9,7 @@ readme = "README.md"
 repository = "https://github.com/paritytech/ink"
 documentation = "https://docs.rs/ink_engine/"
 homepage = "https://www.parity.io/"
-description = "[ink!] Experimental off-chain environment for testing."
+description = "[ink!] Off-chain environment for testing."
 keywords = ["wasm", "parity", "webassembly", "blockchain", "edsl"]
 categories = ["no-std", "embedded"]
 include = ["Cargo.toml", "src/**/*.rs", "README.md", "LICENSE"]

crates/env/Cargo.toml

@@ -56,6 +56,7 @@ std = [
     "ink_allocator/std",
     "ink_prelude/std",
     "ink_primitives/std",
+    "ink_engine/std",
     "scale/std",
     "scale-info/std",
     "secp256k1",
@@ -69,5 +70,4 @@ std = [
 ]
 # Enable contract debug messages via `debug_print!` and `debug_println!`.
 ink-debug = []
-ink-experimental-engine = ["ink_engine"]
 wee-alloc = ["ink_allocator/wee-alloc"]

crates/env/src/backend.rs

@@ -46,7 +46,7 @@ impl ReturnFlags {
     }
 
     /// Returns the underlying `u32` representation.
-    #[cfg(not(feature = "ink-experimental-engine"))]
+    #[cfg(not(feature = "std"))]
     pub(crate) fn into_u32(self) -> u32 {
         self.value
     }