[Variant] feat: Add optional serde_json dependency of parquet-variant

.github/workflows/parquet-variant.yml

@@ -46,8 +46,11 @@ jobs:
           submodules: true
       - name: Setup Rust toolchain
         uses: ./.github/actions/setup-builder
-      - name: Test
+
+      - name: Test parquet-variant
         run: cargo test -p parquet-variant
+      - name: Test parquet-variant with all features
+        run: cargo test -p parquet-variant --all-features
 
   # test compilation
   linux-features:

parquet-variant/Cargo.toml

@@ -35,10 +35,14 @@ rust-version = "1.83"
 [dependencies]
 arrow-schema = { workspace = true }
 chrono = { workspace = true }
-serde_json = "1.0"
+serde_json = { version = "1.0", optional = true }
 base64 = "0.22"
 indexmap = "2.10.0"
 
+[features]
+default = []
+
+serde_json = ["dep:serde_json"]
 
 [lib]
 name = "parquet_variant"

parquet-variant/src/lib.rs

@@ -33,10 +33,12 @@ mod decoder;
 mod variant;
 // TODO: dead code removal
 mod builder;
+#[cfg(feature = "serde_json")]
 mod to_json;
 #[allow(dead_code)]
 mod utils;
 
 pub use builder::*;
+#[cfg(feature = "serde_json")]
 pub use to_json::{variant_to_json, variant_to_json_string, variant_to_json_value};
 pub use variant::*;