/claim #679

Summary

Complete implementation of the Json data type for Issue #679. Introduces first-class JSON representation to zio-blocks with type-safe manipulation and deep Schema integration.

What This Adds

Core Json ADT

• Six standard types: Object, Array, String, Number, Boolean, Null
• Exhaustive pattern matching support
• Number stores values as strings to preserve full precision
• Convenience constructors for all Scala numeric types

Navigation and Selection

• JsonSelection for fluent traversal with error accumulation
• Path expressions via DynamicOptic, array indices, or object keys
• Terminal operations: one, first, toArray

Modification Operations

Transformation and Folding

• transformUp / transformDown for bottom-up and top-down traversal
• transformKeys for bulk field renaming
• foldUp / foldDown with OrFail variants
• filter / filterNot on path-value pairs

Merging

Five built-in strategies:

• Auto / Deep - Recursive object merge with array concatenation
• Shallow - Top-level replacement only
• Concat - Array-focused combination
• Replace - Simple overwrite
• Custom - User-defined merge function

Normalization and Diffing

• normalize - Sort keys, standardize numbers
• sortKeys - Recursive key ordering
• dropNulls / dropEmpty - Remove null values and empty containers
• diff - Produce RFC 6902 JsonPatch between two values

Patching

• patch / patchUnsafe - Apply JsonPatch operations
• Supports: add, remove, replace, move, copy, test
• Batch wrapper for composing multiple operations

Validation

• check / conforms for basic JsonSchema validation
• Covers primitives, arrays, objects with required fields, optionals, unions

Encoding and Decoding

Input formats: String, CharSequence, Array[Byte], Chunk, ByteBuffer, Reader Output formats: String, Array[Byte], Chunk, ByteBuffer, Writer Typed conversion: as[A] / asUnsafe[A] via JsonDecoder

Type Class Integration

• JsonEncoder[A] and JsonDecoder[A] type classes
• Explicit JsonBinaryCodec takes priority over schema derivation

String Interpolators

• p"path.to[0].field" - Path construction
• j"""{"key": "value"}""" - JSON literal parsing
• Implemented for both Scala 2 (blackbox macros) and Scala 3 (inline/quotes)

DynamicValue Interop

• toDynamicValue / fromDynamicValue with full round-trip fidelity
• toKV / fromKV for flat path-value representation
• Temporal values serialize to ISO format strings

Testing

• 1306 tests pass on JVM
• Compiles on JVM, JS, Native
• Compiles on Scala 2.13 and Scala 3.3
• Passes scalafmt validation

Scope Notes

JsonPatch and JsonSchema are working but minimal placeholders, consistent with the issue marking them out-of-scope. Patch functionality supports diff/patch round-trips. Schema validation covers common cases but is not a full JSON Schema implementation.

Demo Video

https://github.com/user-attachments/assets/5b1f59f3-dd41-4854-884c-a2c3939ddac3