Add collect-stream-body

packages/smithy-client/package.json

@@ -25,6 +25,7 @@
   "dependencies": {
     "@smithy/middleware-stack": "workspace:^",
     "@smithy/types": "workspace:^",
+    "@smithy/util-stream": "workspace:^",
     "tslib": "^2.5.0"
   },
   "engines": {

packages/smithy-client/src/collect-stream-body.spec.ts

@@ -0,0 +1,49 @@
+import { Uint8ArrayBlobAdapter } from "@smithy/util-stream";
+
+import { collectBody } from "./collect-stream-body";
+
+describe(collectBody.name, () => {
+  it("passes through Uint8Array", async () => {
+    const body = new Uint8Array();
+    const arr = await collectBody(body, {
+      async streamCollector(stream: any) {
+        return new Uint8Array(stream);
+      },
+    });
+
+    expect(arr).toBe(body);
+  });
+
+  it("uses the contextual streamCollector", async () => {
+    const body = "x";
+    const arr = await collectBody(body, {
+      async streamCollector(stream: any) {
+        return Uint8ArrayBlobAdapter.fromString(stream);
+      },
+    });
+
+    expect(arr.transformToString()).toEqual("x");
+  });
+
+  it("uses the contextual streamCollector for empty string", async () => {
+    const body = "";
+    const arr = await collectBody(body, {
+      async streamCollector(stream: any) {
+        return Uint8ArrayBlobAdapter.fromString(stream);
+      },
+    });
+
+    expect(arr.transformToString()).toEqual("");
+  });
+
+  it("defaults to an empty Uint8Array", async () => {
+    const body = null;
+    const arr = await collectBody(body, {
+      async streamCollector(stream: any) {
+        return Uint8ArrayBlobAdapter.fromString(stream);
+      },
+    });
+
+    expect(arr.transformToString()).toEqual("");
+  });
+});

packages/smithy-client/src/collect-stream-body.ts

@@ -0,0 +1,26 @@
+import { SerdeContext } from "@smithy/types";
+import { Uint8ArrayBlobAdapter } from "@smithy/util-stream";
+
+/**
+ * @internal
+ *
+ * Collect low-level response body stream to Uint8Array.
+ */
+export const collectBody = async (
+  streamBody: any = new Uint8Array(),
+  context: {
+    streamCollector: SerdeContext["streamCollector"];
+  }
+): Promise<Uint8ArrayBlobAdapter> => {
+  if (streamBody instanceof Uint8Array) {
+    return Uint8ArrayBlobAdapter.mutate(streamBody);
+  }
+
+  if (!streamBody) {
+    return Uint8ArrayBlobAdapter.mutate(new Uint8Array());
+  }
+
+  const fromContext = context.streamCollector(streamBody);
+
+  return Uint8ArrayBlobAdapter.mutate(await fromContext);
+};

packages/smithy-client/src/index.ts

@@ -1,5 +1,6 @@
 export * from "./NoOpLogger";
 export * from "./client";
+export * from "./collect-stream-body";
 export * from "./command";
 export * from "./constants";
 export * from "./create-aggregated-client";

yarn.lock

@@ -2263,6 +2263,7 @@ __metadata:
   dependencies:
     "@smithy/middleware-stack": "workspace:^"
     "@smithy/types": "workspace:^"
+    "@smithy/util-stream": "workspace:^"
     "@tsconfig/recommended": 1.0.1
     "@types/node": ^14.14.31
     concurrently: 7.0.0
@@ -2517,7 +2518,7 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@smithy/util-stream@workspace:packages/util-stream":
+"@smithy/util-stream@workspace:^, @smithy/util-stream@workspace:packages/util-stream":
   version: 0.0.0-use.local
   resolution: "@smithy/util-stream@workspace:packages/util-stream"
   dependencies: