[FIX] fix doc tests and refactor code in variant_to_json

Author: carpecodeum

parquet-variant/examples/variant_to_json.rs

@@ -44,9 +44,6 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
     let escaped_json = variant_to_json_string(&special_string)?;
     println!("   Original: Line 1\\nLine 2\\tTabbed\\r\\nWith \"quotes\" and \\\\backslashes");
     println!("   JSON:     {}", escaped_json);
-
-    // Example 3: Unicode support
-    println!("\n🌍 3. Unicode Support:");
 
     let unicode_variants = vec![
         Variant::String("Hello 世界 🌍"),

parquet-variant/src/encoder/json.rs

@@ -39,11 +39,16 @@ use crate::variant::{Variant, VariantArray, VariantObject};
 ///
 /// ```rust
 /// use parquet_variant::{Variant, variant_to_json};
+/// use arrow_schema::ArrowError;
 /// 
-/// let variant = Variant::Int8(42);
-/// let mut buffer = Vec::new();
-/// variant_to_json(&mut buffer, &variant)?;
-/// assert_eq!(String::from_utf8(buffer)?, "42");
+/// fn example() -> Result<(), ArrowError> {
+///     let variant = Variant::Int8(42);
+///     let mut buffer = Vec::new();
+///     variant_to_json(&mut buffer, &variant)?;
+///     assert_eq!(String::from_utf8(buffer).unwrap(), "42");
+///     Ok(())
+/// }
+/// example().unwrap();
 /// ```
 pub fn variant_to_json<W: Write>(
     json_buffer: &mut W,
@@ -144,10 +149,15 @@ fn convert_array_to_json<W: Write>(
 ///
 /// ```rust
 /// use parquet_variant::{Variant, variant_to_json_string};
+/// use arrow_schema::ArrowError;
 /// 
-/// let variant = Variant::String("hello");
-/// let json = variant_to_json_string(&variant)?;
-/// assert_eq!(json, "\"hello\"");
+/// fn example() -> Result<(), ArrowError> {
+///     let variant = Variant::String("hello");
+///     let json = variant_to_json_string(&variant)?;
+///     assert_eq!(json, "\"hello\"");
+///     Ok(())
+/// }
+/// example().unwrap();
 /// ```
 pub fn variant_to_json_string(variant: &Variant) -> Result<String, ArrowError> {
     let mut buffer = Vec::new();
@@ -172,10 +182,15 @@ pub fn variant_to_json_string(variant: &Variant) -> Result<String, ArrowError> {
 /// ```rust
 /// use parquet_variant::{Variant, variant_to_json_value};
 /// use serde_json::Value;
+/// use arrow_schema::ArrowError;
 /// 
-/// let variant = Variant::Int8(42);
-/// let json_value = variant_to_json_value(&variant)?;
-/// assert_eq!(json_value, Value::Number(42.into()));
+/// fn example() -> Result<(), ArrowError> {
+///     let variant = Variant::Int8(42);
+///     let json_value = variant_to_json_value(&variant)?;
+///     assert_eq!(json_value, Value::Number(42.into()));
+///     Ok(())
+/// }
+/// example().unwrap();
 /// ```
 pub fn variant_to_json_value(variant: &Variant) -> Result<Value, ArrowError> {
     match variant {