fix(spec): read float JSON values like iceberg-java

crates/iceberg/src/spec/values/serde.rs

@@ -467,17 +467,7 @@ pub(crate) mod _serde {
                     _ => Err(invalid_err("float")),
                 },
                 RawLiteralEnum::Double(v) => match ty {
-                    Type::Primitive(PrimitiveType::Float) => {
-                        let v_32 = v as f32;
-                        if v_32.is_finite() {
-                            let v_64 = f64::from(v_32);
-                            if (v_64 - v).abs() > f32::EPSILON as f64 {
-                                // there is a precision loss
-                                return Err(invalid_err("double"));
-                            }
-                        }
-                        Ok(Some(Literal::float(v_32)))
-                    }
+                    Type::Primitive(PrimitiveType::Float) => Ok(Some(Literal::float(v as f32))),
                     Type::Primitive(PrimitiveType::Double) => Ok(Some(Literal::double(v))),
                     _ => Err(invalid_err("double")),
                 },

crates/iceberg/src/spec/values/tests.rs

@@ -187,6 +187,53 @@ fn json_double() {
     );
 }
 
+const FLOAT_VALUES: [f32; 6] = [
+    100.1,
+    123.456,
+    -123.456,
+    f32::MAX,
+    f32::MIN,
+    f32::from_bits(1),
+];
+
+#[test]
+fn raw_literal_json_number_to_float() {
+    for value in FLOAT_VALUES {
+        let raw: RawLiteral = serde_json::from_str(&format!("{value:e}")).unwrap();
+
+        assert_eq!(
+            raw.try_into(&Primitive(PrimitiveType::Float)).unwrap(),
+            Some(Literal::float(value))
+        );
+    }
+}
+
+#[test]
+fn raw_literal_avro_double_to_float() {
+    for value in FLOAT_VALUES {
+        for double in [f64::from(value), format!("{value:e}").parse().unwrap()] {
+            let raw: RawLiteral = apache_avro::from_value(&Value::Double(double)).unwrap();
+
+            assert_eq!(
+                raw.try_into(&Primitive(PrimitiveType::Float)).unwrap(),
+                Some(Literal::float(value))
+            );
+        }
+    }
+}
+
+#[test]
+fn raw_literal_double_without_exact_float_narrows_to_nearest() {
+    for (double, expected) in [(16777217.0_f64, 16777216.0_f32), (1.0000000001, 1.0)] {
+        let raw: RawLiteral = serde_json::from_str(&format!("{double:?}")).unwrap();
+
+        assert_eq!(
+            raw.try_into(&Primitive(PrimitiveType::Float)).unwrap(),
+            Some(Literal::float(expected))
+        );
+    }
+}
+
 #[test]
 fn json_date() {
     let record = r#""2017-11-16""#;