Refactor JSON deserialization to assist code generation (#474)

* Add type cast functions to Number

* Add custom errors and token convenience functions to JSON deserialization

* CR feedback

* Move `base64` from smithy-http into smithy-types

* Add more expect functions to the JSON deserializer

Author: jdisanti

codegen/src/main/kotlin/software/amazon/smithy/rust/codegen/smithy/RuntimeTypes.kt

@@ -123,15 +123,15 @@ data class RuntimeType(val name: String?, val dependency: RustDependency?, val n
         fun Base64Encode(runtimeConfig: RuntimeConfig): RuntimeType =
             RuntimeType(
                 "encode",
-                CargoDependency.SmithyHttp(runtimeConfig),
-                "${runtimeConfig.cratePrefix}_http::base64"
+                CargoDependency.SmithyTypes(runtimeConfig),
+                "${runtimeConfig.cratePrefix}_types::base64"
             )
 
         fun Base64Decode(runtimeConfig: RuntimeConfig): RuntimeType =
             RuntimeType(
                 "decode",
-                CargoDependency.SmithyHttp(runtimeConfig),
-                "${runtimeConfig.cratePrefix}_http::base64"
+                CargoDependency.SmithyTypes(runtimeConfig),
+                "${runtimeConfig.cratePrefix}_types::base64"
             )
 
         fun TimestampFormat(runtimeConfig: RuntimeConfig, format: TimestampFormatTrait.Format): RuntimeType {

rust-runtime/inlineable/src/blob_serde.rs

@@ -5,8 +5,7 @@
 
 use serde::de::{Error, Unexpected};
 use serde::{Deserialize, Deserializer, Serialize, Serializer};
-use smithy_http::base64;
-use smithy_types::Blob;
+use smithy_types::{base64, Blob};
 
 pub struct BlobSer<'a>(pub &'a Blob);
 

rust-runtime/smithy-http/Cargo.toml

@@ -30,7 +30,6 @@ tokio-util = { version = "0.6", optional = true}
 
 [dev-dependencies]
 proptest = "1"
-base64 = "0.13.0"
 tokio = {version = "1.6", features = ["macros", "rt", "fs", "io-util"]}
 tokio-stream = "0.1.5"
 tempfile = "3.2.0"

rust-runtime/smithy-http/src/lib.rs

@@ -5,7 +5,6 @@
 
 #![cfg_attr(docsrs, feature(doc_cfg))]
 
-pub mod base64;
 pub mod body;
 pub mod byte_stream;
 pub mod endpoint;