feat(lib): allow chaining of TerraformIterator created resources

examples/typescript/documentation/iterators.ts

@@ -10,6 +10,10 @@ import { Construct } from "constructs";
 import { AwsProvider } from "@cdktf/provider-aws/lib/aws-provider";
 import { S3Bucket } from "@cdktf/provider-aws/lib/s3-bucket";
 
+// DOCS_BLOCK_END:iterators,iterators-complex-types
+import { TerraformAsset } from "cdktf";
+import { S3BucketObject } from "@cdktf/provider-aws/lib/s3-bucket-object";
+// DOCS_BLOCK_START:iterators,iterators-complex-types
 export class IteratorsStack extends TerraformStack {
   constructor(scope: Construct, id: string) {
     super(scope, id);
@@ -78,7 +82,38 @@ export class IteratorsStack extends TerraformStack {
     });
     // DOCS_BLOCK_END:iterators-complex-types
 
-    // DOCS_BLOCK_START:iterators,iterators-complex-types
+    // DOCS_BLOCK_START:iterators-chain
+    const s3BucketConfigurationIterator = TerraformIterator.fromMap({
+      website: {
+        name: "website-static-files",
+        tags: { app: "website" },
+      },
+      images: {
+        name: "images",
+        tags: { app: "image-converter" },
+      },
+    });
+
+    const s3Buckets = new S3Bucket(this, "complex-iterator-buckets", {
+      forEach: s3BucketConfigurationIterator,
+      bucket: s3BucketConfigurationIterator.getString("name"),
+      tags: s3BucketConfigurationIterator.getStringMap("tags"),
+    });
+
+    // This would be TerraformIterator.fromDataSources for data_sources
+    const s3BucketsIterator = TerraformIterator.fromResources(s3Buckets);
+    const helpFile = new TerraformAsset(this, "help", {
+      path: "./help",
+    });
+    new S3BucketObject(this, "object", {
+      forEach: s3BucketsIterator,
+      bucket: s3BucketsIterator.getString("id"),
+      key: "help",
+      source: helpFile.path,
+    });
+    // DOCS_BLOCK_END:iterators-chain
+
+    // DOCS_BLOCK_START:iterators,iterators-complex-types,iterators-chain
   }
 }
-// DOCS_BLOCK_END:iterators,iterators-complex-types
+// DOCS_BLOCK_END:iterators,iterators-complex-types,iterators-chain

examples/typescript/documentation/main.ts

@@ -54,18 +54,18 @@ new VariablesStack(app, "variables");
 
 app.synth();
 
-// Full synth examples for Backends
-localToCloudBackend();
-cloudBackendToCustomBackend(localToCloudBackend());
+// // Full synth examples for Backends
+// localToCloudBackend();
+// cloudBackendToCustomBackend(localToCloudBackend());
 
-// Full synth examples for Stacks
-singleStackRunner();
-multiStackRunner();
-crossStackReferencesRunner();
-stackDependenciesRunner();
-escapeHatchesRunner();
+// // Full synth examples for Stacks
+// singleStackRunner();
+// multiStackRunner();
+// crossStackReferencesRunner();
+// stackDependenciesRunner();
+// escapeHatchesRunner();
 
-// Full synth variable examples
-outputVariablesRunner();
-outputsUsageRunner();
-remoteStateRunner();
+// // Full synth variable examples
+// outputVariablesRunner();
+// outputsUsageRunner();
+// remoteStateRunner();

packages/cdktf/lib/terraform-iterator.ts

@@ -14,6 +14,7 @@ import {
 } from "./complex-computed-list";
 import { TerraformDynamicExpression } from "./terraform-dynamic-expression";
 import { Fn } from "./terraform-functions";
+import { ITerraformResource } from "./terraform-resource";
 import {
   FOR_EXPRESSION_KEY,
   FOR_EXPRESSION_VALUE,
@@ -80,6 +81,26 @@ export abstract class TerraformIterator implements ITerraformIterator {
     return new MapTerraformIterator(map);
   }
 
+  /**
+   * Creates a new iterator from a resource that
+   * has been created with the `for_each` argument.
+   */
+  public static fromResources(
+    resource: ITerraformResource
+  ): ResourceTerraformIterator {
+    return new ResourceTerraformIterator(resource);
+  }
+
+  /**
+   * Creates a new iterator from a data source that
+   * has been created with the `for_each` argument.
+   */
+  public static fromDataSources(
+    resource: ITerraformResource
+  ): ResourceTerraformIterator {
+    return new ResourceTerraformIterator(resource);
+  }
+
   /**
    * @param attribute name of the property to retrieve
    * @returns the given attribute of the current item iterated over as a string
@@ -284,3 +305,46 @@ export class MapTerraformIterator extends TerraformIterator {
     return this._getValue();
   }
 }
+
+// eslint-disable-next-line jsdoc/require-jsdoc
+export class ResourceTerraformIterator extends TerraformIterator {
+  constructor(private readonly element: ITerraformResource) {
+    super();
+
+    if (element.count) {
+      throw new Error(
+        "Cannot create iterator from resource with count argument. Please use the same TerraformCount used in the resource passed here instead."
+      );
+    }
+
+    if (!element.forEach) {
+      throw new Error(
+        "Cannot create iterator from resource without for_each argument"
+      );
+    }
+  }
+
+  /**
+   * Returns the currenty entry in the list or set that is being iterated over.
+   * For lists this is the same as `iterator.value`. If you need the index,
+   * use count using the escape hatch:
+   * https://developer.hashicorp.com/terraform/cdktf/concepts/resources#escape-hatch
+   */
+  public get key(): any {
+    return this._getKey();
+  }
+
+  /**
+   * Returns the value of the current item iterated over.
+   */
+  public get value(): any {
+    return this._getValue();
+  }
+
+  /**
+   * @internal used by TerraformResource to set the for_each expression
+   */
+  public _getForEachExpression(): any {
+    return this.element.fqn; // no wrapping necessary for resources
+  }
+}

packages/cdktf/test/dynamic-block.test.ts

@@ -88,3 +88,29 @@ test("dynamic blocks are properly rendered for providers", () => {
     },
   ]);
 });
+
+test("chained iterators used in dynamic blocks", () => {
+  const app = Testing.app();
+  const stack = new TerraformStack(app, "test");
+  const it = TerraformIterator.fromList(["a", "b", "c"]);
+  const source = new TestResource(stack, "test", {
+    forEach: it,
+    name: "foo",
+  });
+
+  const chainedIt = TerraformIterator.fromResources(source);
+  new TestResource(stack, "chained", {
+    name: "foo",
+    listBlock: chainedIt.dynamic({ name: chainedIt.getString("string_value") }),
+  });
+
+  const synth = JSON.parse(Testing.synth(stack));
+  expect(synth).toHaveProperty(
+    "resource.test_resource.chained.dynamic.list_block.for_each",
+    "${test_resource.test}"
+  );
+  expect(synth).toHaveProperty(
+    "resource.test_resource.chained.dynamic.list_block.content",
+    { name: "${each.value.string_value}" }
+  );
+});

packages/cdktf/test/iterator.test.ts

@@ -393,3 +393,62 @@ test("count can count references", () => {
     "data${count.index}"
   );
 });
+
+test("chained iterators used in for_each", () => {
+  const app = Testing.app();
+  const stack = new TerraformStack(app, "test");
+  const it = TerraformIterator.fromList(["a", "b", "c"]);
+  const source = new TestResource(stack, "test", {
+    forEach: it,
+    name: "foo",
+  });
+
+  const chainedIt = TerraformIterator.fromResources(source);
+  new TestResource(stack, "chained", {
+    forEach: chainedIt,
+    name: chainedIt.getString("string_value"),
+  });
+
+  const synth = JSON.parse(Testing.synth(stack));
+  expect(synth).toHaveProperty(
+    "resource.test_resource.chained.for_each",
+    "${test_resource.test}"
+  );
+  expect(synth).toHaveProperty(
+    "resource.test_resource.chained.name",
+    "${each.value.string_value}"
+  );
+});
+
+test("chained iterators from singular resources", () => {
+  const app = Testing.app();
+  const stack = new TerraformStack(app, "test");
+  const source = new TestResource(stack, "test", {
+    name: "foo",
+  });
+
+  expect(() => {
+    TerraformIterator.fromResources(source);
+  }).toThrowErrorMatchingInlineSnapshot(
+    `"Cannot create iterator from resource without for_each argument"`
+  );
+});
+
+test("chained iterators used with count", () => {
+  const app = Testing.app();
+  const stack = new TerraformStack(app, "test");
+
+  const resource = new TestResource(stack, "test", { name: "foo" });
+  const it = TerraformCount.of(resource.numericValue);
+
+  const datasFromCount = new TestDataSource(stack, "test_data", {
+    count: it,
+    name: `data${it.index}`,
+  });
+
+  expect(() => {
+    TerraformIterator.fromDataSources(datasFromCount);
+  }).toThrowErrorMatchingInlineSnapshot(
+    `"Cannot create iterator from resource with count argument. Please use the same TerraformCount used in the resource passed here instead."`
+  );
+});

tools/documentation-generation/yarn.lock

@@ -73,23 +73,23 @@ archiver-utils@^2.1.0:
     normalize-path "^3.0.0"
     readable-stream "^2.0.0"
 
-[email protected].1:
-  version "5.3.1"
-  resolved "https://registry.yarnpkg.com/archiver/-/archiver-5.3.1.tgz#21e92811d6f09ecfce649fbefefe8c79e57cbbb6"
-  integrity sha512-8KyabkmbYrH+9ibcTScQ1xCJC/CGcugdVIwB+53f5sZziXgwUh3iXlAlANMxcZyDEfTHMe6+Z5FofV8nopXP7w==
+[email protected].2:
+  version "5.3.2"
+  resolved "https://registry.yarnpkg.com/archiver/-/archiver-5.3.2.tgz#99991d5957e53bd0303a392979276ac4ddccf3b0"
+  integrity sha512-+25nxyyznAXF7Nef3y0EbBeqmGZgeN/BxHX29Rs39djAfaFalmQ89SE6CWyDCHzGL0yt/ycBtNOmGTW0FyGWNw==
   dependencies:
     archiver-utils "^2.1.0"
-    async "^3.2.3"
+    async "^3.2.4"
     buffer-crc32 "^0.2.1"
     readable-stream "^3.6.0"
-    readdir-glob "^1.0.0"
+    readdir-glob "^1.1.2"
     tar-stream "^2.2.0"
     zip-stream "^4.1.0"
 
-async@^3.2.3:
-  version "3.2.4"
-  resolved "https://registry.yarnpkg.com/async/-/async-3.2.4.tgz#2d22e00f8cddeb5fde5dd33522b56d1cf569a81c"
-  integrity sha512-iAB+JbDEGXhyIUavoDl9WP/Jj106Kz9DEn1DPgYw5ruDn0e3Wgi3sKFm55sASdGBNOQB8F59d9qQ7deqrHA8wQ==
+async@^3.2.4:
+  version "3.2.5"
+  resolved "https://registry.yarnpkg.com/async/-/async-3.2.5.tgz#ebd52a8fdaf7a2289a24df399f8d8485c8a46b66"
+  integrity sha512-baNZyqaaLhyLVKm/DlvdW051MSgO6b8eVfIezl9E5PqWxFgzLm/wQntEW4zOytVburDEr0JlALEpdOFwvErLsg==
 
 balanced-match@^1.0.0:
   version "1.0.2"
@@ -146,9 +146,9 @@ case@^1.6.3:
 "cdktf@file:../../packages/cdktf":
   version "0.0.0"
   dependencies:
-    archiver "5.3.1"
+    archiver "5.3.2"
     json-stable-stringify "^1.0.2"
-    semver "^7.5.3"
+    semver "^7.5.4"
 
 chalk@^4, chalk@^4.1.2:
   version "4.1.2"
@@ -497,10 +497,10 @@ readable-stream@^3.1.1, readable-stream@^3.4.0, readable-stream@^3.6.0:
     string_decoder "^1.1.1"
     util-deprecate "^1.0.1"
 
-readdir-glob@^1.0.0:
-  version "1.1.2"
-  resolved "https://registry.yarnpkg.com/readdir-glob/-/readdir-glob-1.1.2.tgz#b185789b8e6a43491635b6953295c5c5e3fd224c"
-  integrity sha512-6RLVvwJtVwEDfPdn6X6Ille4/lxGl0ATOY4FN/B9nxQcgOazvvI0nodiD19ScKq0PvA/29VpaOQML36o5IzZWA==
+readdir-glob@^1.1.2:
+  version "1.1.3"
+  resolved "https://registry.yarnpkg.com/readdir-glob/-/readdir-glob-1.1.3.tgz#c3d831f51f5e7bfa62fa2ffbe4b508c640f09584"
+  integrity sha512-v05I2k7xN8zXvPD9N+z/uhXPaj0sUFCe2rcWZIpBsqxfP7xXFQ0tipAd/wjj1YxWyWtUS5IDJpOG82JKt2EAVA==
   dependencies:
     minimatch "^5.1.0"
 
@@ -524,13 +524,6 @@ safe-buffer@~5.2.0:
   resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.2.1.tgz#1eaf9fa9bdb1fdd4ec75f58f9cdb4e6b7827eec6"
   integrity sha512-rp3So07KcdmmKbGvgaNxQSJr7bGVSVk5S9Eq1F+ppbRo70+YeaDxkw5Dd8NPN+GD6bjnYm2VuPuCXmpuYvmCXQ==
 
-semver@^7.5.3:
-  version "7.5.3"
-  resolved "https://registry.yarnpkg.com/semver/-/semver-7.5.3.tgz#161ce8c2c6b4b3bdca6caadc9fa3317a4c4fe88e"
-  integrity sha512-QBlUtyVk/5EeHbi7X0fw6liDZc7BBmEaSYn01fMU1OUYbf6GPsbTtd8WmnqbI20SeycoHSeiybkE/q1Q+qlThQ==
-  dependencies:
-    lru-cache "^6.0.0"
-
 semver@^7.5.4:
   version "7.5.4"
   resolved "https://registry.yarnpkg.com/semver/-/semver-7.5.4.tgz#483986ec4ed38e1c6c48c34894a9182dbff68a6e"