From fad0c445f3a65c1a0e52d0adb334cd65d69e7a51 Mon Sep 17 00:00:00 2001
From: Luke Chisholm <luke.chisholm6@gmail.com>
Date: Mon, 15 Sep 2025 15:20:21 -0700
Subject: [PATCH] fix(lib): properly interpolate dependencies in
 replaceTriggeredBy

This change will address the bug identified in https://github.com/hashicorp/terraform-cdk/issues/3196
where using replaceTriggeredBy will improperly generate a tokenized address.
---
 packages/cdktf/lib/terraform-resource.ts      | 12 +++-----
 packages/cdktf/lib/tfExpression.ts            | 28 +++++++++++++++++++
 .../test/__snapshots__/resource.test.ts.snap  |  4 +--
 3 files changed, 34 insertions(+), 10 deletions(-)

diff --git a/packages/cdktf/lib/terraform-resource.ts b/packages/cdktf/lib/terraform-resource.ts
index 675ea7ba29..a0abd8bc5e 100644
--- a/packages/cdktf/lib/terraform-resource.ts
+++ b/packages/cdktf/lib/terraform-resource.ts
@@ -11,7 +11,7 @@ import {
   processDynamicAttributesForHcl,
 } from "./util";
 import { ITerraformDependable } from "./terraform-dependable";
-import { ref, dependable } from "./tfExpression";
+import { ref, dependable, replaceTriggeredBy } from "./tfExpression";
 import { IResolvable } from "./tokens/resolvable";
 import { IInterpolatingParent } from "./terraform-addressable";
 import { ITerraformIterator } from "./terraform-iterator";
@@ -78,13 +78,9 @@ export function lifecycleToTerraform(
     ...lifecycle,
     ...(lifecycle?.replaceTriggeredBy?.length
       ? {
-          replaceTriggeredBy: lifecycle?.replaceTriggeredBy?.map((x) => {
-            if (typeof x === "string") {
-              return x;
-            } else {
-              return x.fqn;
-            }
-          }),
+          replaceTriggeredBy: lifecycle?.replaceTriggeredBy?.map((x) =>
+            replaceTriggeredBy(x),
+          ),
         }
       : undefined),
   };
diff --git a/packages/cdktf/lib/tfExpression.ts b/packages/cdktf/lib/tfExpression.ts
index f9baf57295..511fae77ec 100644
--- a/packages/cdktf/lib/tfExpression.ts
+++ b/packages/cdktf/lib/tfExpression.ts
@@ -466,6 +466,33 @@ export function dependable(dependable: ITerraformDependable): string {
   return Token.asString(new Dependable(dependable));
 }
 
+// eslint-disable-next-line jsdoc/require-jsdoc
+class ReplaceTriggeredBy extends TFExpression {
+  constructor(private readonly trigger: ITerraformDependable | string) {
+    super(trigger);
+  }
+
+  public resolve(context: IResolveContext) {
+    context.suppressBraces = true;
+
+    if (typeof this.trigger === "string") {
+      return context.resolve(this.trigger);
+    }
+    return context.resolve(this.trigger.fqn);
+  }
+}
+
+/**
+ * Takes either a full resource or a resource property and then
+ * returns the logical address without braces/interpolation to
+ * be used in replaceTriggeredBy directives.
+ */
+export function replaceTriggeredBy(
+  trigger: ITerraformDependable | string,
+): string {
+  return Token.asString(new ReplaceTriggeredBy(trigger));
+}
+
 export type Expression =
   | Reference
   | FunctionCall
@@ -473,6 +500,7 @@ export type Expression =
   | ConditionalExpression
   | OperatorExpression
   | Dependable
+  | ReplaceTriggeredBy
   | ForExpression
   | string
   | string[]
diff --git a/packages/cdktf/test/__snapshots__/resource.test.ts.snap b/packages/cdktf/test/__snapshots__/resource.test.ts.snap
index 21de4c79f7..dc5d942d90 100644
--- a/packages/cdktf/test/__snapshots__/resource.test.ts.snap
+++ b/packages/cdktf/test/__snapshots__/resource.test.ts.snap
@@ -456,8 +456,8 @@ exports[`supports resource and attribute references in lifecycle.replaceTriggere
       "simple": {
         "lifecycle": {
           "replace_triggered_by": [
-            "\${test_resource.other}",
-            "\${test_resource.other.string_value}"
+            "test_resource.other",
+            "test_resource.other.string_value"
           ]
         },
         "name": "foo"