add structIterator generator

Author: kuhe

.changeset/two-berries-repeat.md

@@ -0,0 +1,5 @@
+---
+"@smithy/smithy-client": minor
+---
+
+add schema property to Command class

packages/core/src/submodules/cbor/CborCodec.ts

@@ -51,14 +51,18 @@ export class CborShapeSerializer implements ShapeSerializer {
       const ns = NormalizedSchema.of(schemaRef);
       const sparse = !!ns.getMergedTraits().sparse;
 
-      if (Array.isArray(_)) {
+      if (ns.isListSchema() && Array.isArray(_)) {
         if (!sparse) {
           return _.filter((item) => item != null);
         }
       } else if (_ && typeof _ === "object") {
-        if (!sparse || ns.isStructSchema()) {
+        const members = ns.getMemberSchemas();
+        const isStruct = ns.isStructSchema();
+        if (!sparse || isStruct) {
           for (const [k, v] of Object.entries(_)) {
-            if (v == null) {
+            const filteredOutByNonSparse = !sparse && v == null;
+            const filteredOutByUnrecognizedMember = isStruct && !(k in members);
+            if (filteredOutByNonSparse || filteredOutByUnrecognizedMember) {
               delete _[k];
             }
           }
@@ -157,12 +161,8 @@ export class CborShapeDeserializer implements ShapeDeserializer {
           }
         }
       } else if (ns.isStructSchema()) {
-        for (const key of Object.keys(value)) {
-          const targetSchema = ns.getMemberSchema(key);
-          if (targetSchema === undefined) {
-            continue;
-          }
-          newObject[key] = this.readValue(targetSchema, value[key]);
+        for (const [key, memberSchema] of ns.structIterator()) {
+          newObject[key] = this.readValue(memberSchema, value[key]);
         }
       }
       return newObject;

packages/core/src/submodules/protocols/HttpProtocol.ts

@@ -110,7 +110,7 @@ export abstract class HttpProtocol implements ClientProtocol<IHttpRequest, IHttp
     if (operationNs.getMergedTraits().endpoint) {
       let hostPrefix = operationNs.getMergedTraits().endpoint?.[0];
       if (typeof hostPrefix === "string") {
-        const hostLabelInputs = Object.entries(inputNs.getMemberSchemas()).filter(
+        const hostLabelInputs = [...inputNs.structIterator()].filter(
           ([, member]) => member.getMergedTraits().hostLabel
         );
         for (const [name] of hostLabelInputs) {
@@ -154,7 +154,7 @@ export abstract class HttpProtocol implements ClientProtocol<IHttpRequest, IHttp
     const ns = NormalizedSchema.of(schema);
     const nonHttpBindingMembers = [] as string[];
 
-    for (const [memberName, memberSchema] of Object.entries(ns.getMemberSchemas())) {
+    for (const [memberName, memberSchema] of ns.structIterator()) {
       const memberTraits = memberSchema.getMemberTraits();
 
       if (memberTraits.httpPayload) {

packages/core/src/submodules/schema/schemas/NormalizedSchema.spec.ts

@@ -173,6 +173,20 @@ describe(NormalizedSchema.name, () => {
     });
   });
 
+  describe("iteration", () => {
+    it("iterates over member schemas", () => {
+      const iteration = Array.from(ns.structIterator());
+      const entries = Object.entries(ns.getMemberSchemas());
+      for (let i = 0; i < iteration.length; i++) {
+        const [name, schema] = iteration[i];
+        const [entryName, entrySchema] = entries[i];
+        expect(name).toBe(entryName);
+        expect(schema.getMemberName()).toEqual(entrySchema.getMemberName());
+        expect(schema.getMergedTraits()).toEqual(entrySchema.getMergedTraits());
+      }
+    });
+  });
+
   describe("traits", () => {
     const member: MemberSchema = [sim("ack", "SimpleString", 0, { idempotencyToken: 1 }), 0b0000_0001];
     const ns = NormalizedSchema.of(member, "member_name");

packages/core/src/submodules/schema/schemas/NormalizedSchema.ts

@@ -371,6 +371,11 @@ export class NormalizedSchema implements INormalizedSchema {
   }
 
   /**
+   * This can be used for checking the members as a hashmap.
+   * Prefer the structIterator method for iteration.
+   *
+   * This does NOT return list and map members, it is only for structures.
+   *
    * @returns a map of member names to member schemas (normalized).
    */
   public getMemberSchemas(): Record<string, NormalizedSchema> {
@@ -389,6 +394,22 @@ export class NormalizedSchema implements INormalizedSchema {
     return {};
   }
 
+  /**
+   * Allows iteration over members of a structure schema.
+   * Each yield is a pair of the member name and member schema.
+   *
+   * This avoids the overhead of calling Object.entries(ns.getMemberSchemas()).
+   */
+  public *structIterator(): Generator<[string, NormalizedSchema], undefined, undefined> {
+    if (!this.isStructSchema()) {
+      throw new Error("@smithy/core/schema - cannot acquire structIterator on non-struct schema.");
+    }
+    const struct = this.getSchema() as StructureSchema;
+    for (let i = 0; i < struct.memberNames.length; ++i) {
+      yield [struct.memberNames[i], NormalizedSchema.memberFrom([struct.memberList[i], 0], struct.memberNames[i])];
+    }
+  }
+
   /**
    * @returns a last-resort human-readable name for the schema if it has no other identifiers.
    */

packages/core/src/submodules/serde/copyDocumentWithTransform.ts

@@ -45,7 +45,7 @@ export const copyDocumentWithTransform = (
           newObject[key] = copyDocumentWithTransform(source[key], ns.getValueSchema(), transform);
         }
       } else if (ns.isStructSchema()) {
-        for (const [key, memberSchema] of Object.entries(ns.getMemberSchemas())) {
+        for (const [key, memberSchema] of ns.structIterator()) {
           newObject[key] = copyDocumentWithTransform(source[key], memberSchema, transform);
         }
       } else if (ns.isDocumentSchema()) {

packages/smithy-client/src/command.ts

@@ -11,6 +11,8 @@ import type {
   Logger,
   MetadataBearer,
   MiddlewareStack as IMiddlewareStack,
+  Mutable,
+  OperationSchema,
   OptionalParameter,
   Pluggable,
   RequestHandler,
@@ -31,6 +33,7 @@ export abstract class Command<
 {
   public abstract input: Input;
   public readonly middlewareStack: IMiddlewareStack<Input, Output> = constructStack<Input, Output>();
+  public readonly schema?: OperationSchema;
 
   /**
    * Factory for Command ClassBuilder.
@@ -131,6 +134,8 @@ class ClassBuilder<
   private _outputFilterSensitiveLog = (_: any) => _;
   private _serializer: (input: I, context: SerdeContext | any) => Promise<IHttpRequest> = null as any;
   private _deserializer: (output: IHttpResponse, context: SerdeContext | any) => Promise<O> = null as any;
+  private _operationSchema?: OperationSchema;
+
   /**
    * Optional init callback.
    */
@@ -212,6 +217,16 @@ class ClassBuilder<
     this._deserializer = deserializer;
     return this;
   }
+
+  /**
+   * Sets input/output schema for the operation.
+   */
+  public sc(operation: OperationSchema): ClassBuilder<I, O, C, SI, SO> {
+    this._operationSchema = operation;
+    this._smithyContext.operationSchema = operation;
+    return this;
+  }
+
   /**
    * @returns a Command class with the classBuilder properties.
    */
@@ -241,6 +256,7 @@ class ClassBuilder<
         super();
         this.input = input ?? ({} as unknown as I);
         closure._init(this);
+        (this as Mutable<typeof this>).schema = closure._operationSchema;
       }
 
       /**