Update Earthfile

Author: theHamsta

Cargo.lock

@@ -1,7 +1,13 @@
+VERSION 0.6
 FROM rustlang/rust:nightly-buster-slim
 WORKDIR /rustexample
 
+all:
+    BUILD +build
+    BUILD +check
+
 install-chef:
+   ENV CARGO_UNSTABLE_SPARSE_REGISTRY=true
    RUN cargo install --debug cargo-chef
 
 prepare-cache:
@@ -14,17 +20,25 @@ prepare-cache:
 build-cache:
     FROM +install-chef
     COPY +prepare-cache/recipe.json ./
+    RUN cargo chef cook --release
     RUN cargo chef cook
     SAVE ARTIFACT target
     SAVE ARTIFACT $CARGO_HOME cargo_home
 
 build:
     COPY --dir src Cargo.lock Cargo.toml .
     COPY +build-cache/cargo_home $CARGO_HOME
+    ENV CARGO_UNSTABLE_SPARSE_REGISTRY=true
     RUN cargo build --release
 	RUN strip target/release/highlight-assertions 
     SAVE ARTIFACT target/release/highlight-assertions AS LOCAL earthly-artifacts/highlight-assertions
 
+check:
+    COPY --dir src Cargo.lock Cargo.toml .
+    COPY +build-cache/cargo_home $CARGO_HOME
+    ENV CARGO_UNSTABLE_SPARSE_REGISTRY=true
+    RUN cargo fmt --check
+    RUN cargo clippy
 #docker:
     #FROM debian:buster-slim
     #COPY +build/example-rust example-rust