fix(sdk): custom bind method on awscdk targets (#3769)

Following @eladb's recommendation in PR #3398, I removed the import of `target-awscdk` and `target-tf-aws`, and checked if the `host` implements the methods of the `IAwsFunction` interface. This way, the error that was occurring due to not having `aws-cdk-lib` globally installed no longer happens.

## Checklist

- [x] Title matches [Winglang's style guide](https://www.winglang.io/contributing/start-here/pull_requests#how-are-pull-request-titles-formatted)
- [x] Description explains motivation and solution
- [x] Tests added (always)
- [ ] Docs updated (only required for features)
- [ ] Added `pr/e2e-full` label if this feature requires end-to-end testing

*By submitting this pull request, I confirm that my contribution is made under the terms of the [Wing Cloud Contribution License](https://github.com/winglang/wing/blob/main/CONTRIBUTION_LICENSE.md)*.

examples/tests/valid/dynamo.js

@@ -1,4 +1,4 @@
-const { DynamoDBClient, PutItemCommand } = require("@aws-sdk/client-dynamodb");
+const { DynamoDBClient, PutItemCommand, GetItemCommand } = require("@aws-sdk/client-dynamodb");
 
 const client = new DynamoDBClient({});
 
@@ -7,8 +7,19 @@ export async function _putItem(tableName, item) {
     TableName: tableName,
     Item: item,
   });
-  
+
   const response = await client.send(command);
   console.log(response);
   return;
 }
+
+export async function _getItem(tableName, key) {
+  const command = new GetItemCommand({
+    TableName: tableName,
+    Key: key
+  });
+
+  const response = await client.send(command);
+  console.log(response);
+  return response;
+}

examples/tests/valid/dynamo_awscdk.w

@@ -0,0 +1,123 @@
+/*\
+skip: true
+\*/
+// this example only works on AWS (intentionally)
+
+bring "aws-cdk-lib" as awscdk;
+bring aws;
+bring cloud;
+bring util;
+
+enum AttributeType {
+  String,
+  Number,
+  Binary,
+}
+
+struct Attribute {
+  type: AttributeType;
+  value: Json;
+}
+
+class DynamoTable {
+  table: awscdk.aws_dynamodb.Table;
+  tableName: str;
+  init() {
+    let target = util.env("WING_TARGET");
+    if target != "awscdk" {
+      throw("Unsupported target: ${target} (expected 'awscdk')");
+    }
+
+    this.table = new awscdk.aws_dynamodb.Table(
+      tableName: this.node.addr,
+      billingMode: awscdk.aws_dynamodb.BillingMode.PAY_PER_REQUEST,
+      removalPolicy: awscdk.RemovalPolicy.DESTROY,
+      partitionKey: awscdk.aws_dynamodb.Attribute {
+        name: "Flavor",
+        type: awscdk.aws_dynamodb.AttributeType.STRING,
+      },
+    );
+    this.tableName = this.table.tableName;
+  }
+
+  bind(host: std.IInflightHost, ops: Array<str>) {
+    if let host = aws.Function.from(host) {
+      if ops.contains("putItem") {
+        host.addPolicyStatements([aws.PolicyStatement {
+          actions: ["dynamodb:PutItem"],
+          resources: [this.table.tableArn],
+          effect: aws.Effect.ALLOW,
+        }]);
+      }
+
+      if ops.contains("getItem") {
+        host.addPolicyStatements([aws.PolicyStatement {
+          actions: ["dynamodb:GetItem"],
+          resources: [this.table.tableArn],
+          effect: aws.Effect.ALLOW,
+        }]);
+      }
+    }
+  }
+
+  extern "./dynamo.js" inflight _putItem(tableName: str, item: Json): void;
+  inflight putItem(item: Map<Attribute>) {
+    let json = this._itemToJson(item);
+    this._putItem(this.tableName, json);
+  }
+
+  extern "./dynamo.js" inflight _getItem(tableName: str, key: Json): Json;
+  inflight getItem(key: Map<Attribute>): Json {
+    let json = this._itemToJson(key);
+    return this._getItem(this.tableName, json);
+  }
+
+  inflight _itemToJson(item: Map<Attribute>): Json {
+    let json = MutJson {};
+    for key in item.keys() {
+      let attribute = item.get(key);
+      let attributeTypeStr = this._attributeTypeToString(attribute.type);
+
+      let innerJson = MutJson {};
+      innerJson.set(attributeTypeStr, attribute.value);
+      json.set(key, innerJson);
+    }
+    return json;
+  }
+
+  inflight _attributeTypeToString(type: AttributeType): str {
+    if type == AttributeType.String {
+      return "S";
+    } elif type == AttributeType.Number {
+      return "N";
+    } elif type == AttributeType.Binary {
+      return "B";
+    }
+  }
+}
+
+// --- tests ---
+
+let table = new DynamoTable();
+
+test "cdk table" {
+  table.putItem({
+    "Flavor" => Attribute {
+      type: AttributeType.String,
+      value: "Chocolate",
+    },
+    "Quantity" => Attribute {
+      type: AttributeType.String,
+      value: "20Kg"
+    }
+  });
+
+  let c = table.getItem({
+    "Flavor" => Attribute {
+      type: AttributeType.String,
+      value: "Chocolate",
+    }
+  });
+  assert(c.get("Item").get("Flavor").get("S").asStr() == "Chocolate");
+  assert(c.get("Item").get("Quantity").get("S").asStr() == "20Kg");
+}

libs/wingsdk/src/shared-aws/function.ts

@@ -1,6 +1,5 @@
 import { PolicyStatement } from "./types";
 import { IInflightHost } from "../std";
-import { Function as TfAwsFunction } from "../target-tf-aws";
 
 /**
  * A shared interface for AWS functions.
@@ -30,10 +29,16 @@ export class Function {
    * @param host The inflight host.
    */
   public static from(host: IInflightHost): IAwsFunction | undefined {
-    if (host instanceof TfAwsFunction) {
+    if (this.isAwsFunction(host)) {
       return host;
     }
-
     return undefined;
   }
+
+  private static isAwsFunction(obj: any): obj is IAwsFunction {
+    return (
+      typeof obj.addPolicyStatements === "function" &&
+      typeof obj.addEnvironment === "function"
+    );
+  }
 }

libs/wingsdk/src/target-awscdk/function.ts

@@ -11,15 +11,15 @@ import { Construct } from "constructs";
 import * as cloud from "../cloud";
 import * as core from "../core";
 import { createBundle } from "../shared/bundling";
-import { PolicyStatement } from "../shared-aws";
+import { IAwsFunction, PolicyStatement } from "../shared-aws";
 import { IInflightHost } from "../std";
 
 /**
  * AWS implementation of `cloud.Function`.
  *
  * @inflight `@winglang/sdk.cloud.IFunctionClient`
  */
-export class Function extends cloud.Function {
+export class Function extends cloud.Function implements IAwsFunction {
   private readonly function: CdkFunction;
   /** Function ARN */
   public readonly arn: string;