fix(deps): Remove unused dependencies, and check for them in CI (#6216)

* Remove unused dependencies

* Check for newly unused dependencies in CI

* Use the correct grep command

* Always show cargo machete output

* Ignore cargo machete exit status, use grep instead

* Use if instead of && and subshells

* Invert if logic

.github/workflows/continous-integration-os.patch.yml

@@ -60,3 +60,10 @@ jobs:
 
     steps:
       - run: 'echo "No build required"'
+
+  unused-deps:
+    name: Check for unused dependencies
+    runs-on: ubuntu-latest
+
+    steps:
+      - run: 'echo "No build required"'

.github/workflows/continous-integration-os.yml

@@ -279,3 +279,40 @@ jobs:
         with:
           command: check ${{ matrix.checks }}
           arguments: --workspace ${{ matrix.features }}
+
+  unused-deps:
+    name: Check for unused dependencies
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout git repository
+        uses: actions/[email protected]
+        with:
+          persist-credentials: false
+
+      - name: Install toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          profile: minimal
+          override: true
+
+      - name: Install cargo-machete
+        uses: baptiste0928/cargo-install@v1
+        with:
+          crate: cargo-machete
+
+      - name: Check unused dependencies
+        # Exclude macro and transitive dependencies by filtering them out of the output,
+        # then if there are any more unused dependencies, fail the job.
+        run: |
+          echo "-- full cargo machete output, including ignored dependencies --"
+          cargo machete --skip-target-dir || true
+          echo "-- unused dependencies are below this line, full output is above --"
+          if (cargo machete --skip-target-dir 2>/dev/null || true) | \
+          grep -v -e gumdrop -e humantime-serde -e tinyvec -e "found the following" -e Cargo.toml -e Done; then
+              echo "New unused dependencies were found, please remove them!"
+              exit 1
+          else
+              echo "No unused dependencies found."
+          fi

zebra-chain/Cargo.toml

@@ -33,13 +33,10 @@ bench = ["zebra-test"]
 [dependencies]
 
 # Cryptography
-aes = "0.7.5"
-bech32 = "0.9.1"
 bitvec = "1.0.1"
 bitflags = "1.3.2"
 blake2b_simd = "1.0.1"
 blake2s_simd = "1.0.1"
-bls12_381 = "0.7.0"
 bs58 = { version = "0.4.0", features = ["check"] }
 byteorder = "1.4.3"
 equihash = "0.2.0"
@@ -53,7 +50,6 @@ ripemd = "0.1.3"
 # Matches version used by hdwallet
 secp256k1 = { version = "0.21.3", features = ["serde"] }
 sha2 = { version = "0.9.9", features = ["compress"] }
-subtle = "2.4.1"
 uint = "0.9.5"
 x25519-dalek = { version = "2.0.0-pre.1", features = ["serde"] }
 

zebra-consensus/Cargo.toml

@@ -30,7 +30,6 @@ rand = { version = "0.8.5", package = "rand" }
 rayon = "1.6.1"
 
 chrono = { version = "0.4.23", default-features = false, features = ["clock", "std"] }
-dirs = "4.0.0"
 displaydoc = "0.2.3"
 lazy_static = "1.4.0"
 once_cell = "1.17.1"

zebra-rpc/Cargo.toml

@@ -25,7 +25,6 @@ getblocktemplate-rpcs = [
 # Test-only features
 proptest-impl = [
     "proptest",
-    "proptest-derive",
     "zebra-consensus/proptest-impl",
     "zebra-state/proptest-impl",
     "zebra-network/proptest-impl",
@@ -52,7 +51,6 @@ tokio = { version = "1.25.0", features = ["time", "rt-multi-thread", "macros", "
 tower = "0.4.13"
 
 tracing = "0.1.37"
-tracing-futures = "0.2.5"
 
 hex = { version = "0.4.3", features = ["serde"] }
 serde = { version = "1.0.152", features = ["serde_derive"] }
@@ -64,7 +62,6 @@ zcash_address = { version = "0.2.0", optional = true }
 
 # Test-only feature proptest-impl
 proptest = { version = "0.10.1", optional = true }
-proptest-derive = { version = "0.3.0", optional = true }
 
 zebra-chain = { path = "../zebra-chain" }
 zebra-consensus = { path = "../zebra-consensus" }
@@ -77,7 +74,6 @@ zebra-state = { path = "../zebra-state" }
 insta = { version = "1.28.0", features = ["redactions", "json", "ron"] }
 
 proptest = "0.10.1"
-proptest-derive = "0.3.0"
 
 thiserror = "1.0.38"
 tokio = { version = "1.25.0", features = ["full", "tracing", "test-util"] }

zebra-state/Cargo.toml

@@ -26,7 +26,6 @@ proptest-impl = [
 bincode = "1.3.3"
 chrono = { version = "0.4.23", default-features = false, features = ["clock", "std"] }
 dirs = "4.0.0"
-displaydoc = "0.2.3"
 futures = "0.3.26"
 hex = "0.4.3"
 indexmap = "1.9.2"

zebrad/Cargo.toml

@@ -101,7 +101,6 @@ zebra-state = { path = "../zebra-state" }
 abscissa_core = "0.5"
 gumdrop = { version = "0.7", features = ["default_expr"]}
 chrono = { version = "0.4.23", default-features = false, features = ["clock", "std"] }
-humantime = "2.1.0"
 humantime-serde = "1.1.1"
 indexmap = "1.9.2"
 lazy_static = "1.4.0"