From 68c557b381357cd8ac83935397758ad371e01059 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Mon, 13 Apr 2026 14:58:03 +0200
Subject: [PATCH] backend-plugin-api: tighten internal any usage (#33867)

* backend-plugin-api: tighten internal any usage

Replace internal `any` type annotations with proper types:

- Use `'root' | 'plugin'` union in DepsToInstances conditional type
  and createServiceRef implementation signature
- Use Error type guard with object cast fallback in
  isDatabaseConflictError instead of `as any`

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
Made-with: Cursor

* Use isError in isDatabaseConflictError

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
Made-with: Cursor

* Update changeset wording per review feedback

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
Made-with: Cursor

---------

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 .changeset/tighten-internal-any-usage.md                    | 5 +++++
 packages/backend-plugin-api/src/services/system/types.ts    | 4 ++--
 .../backend-plugin-api/src/services/utilities/database.ts   | 4 +++-
 packages/backend-plugin-api/src/wiring/types.ts             | 6 +++++-
 4 files changed, 15 insertions(+), 4 deletions(-)
 create mode 100644 .changeset/tighten-internal-any-usage.md

diff --git a/.changeset/tighten-internal-any-usage.md b/.changeset/tighten-internal-any-usage.md
new file mode 100644
index 0000000000..acbeecdd3e
--- /dev/null
+++ b/.changeset/tighten-internal-any-usage.md
@@ -0,0 +1,5 @@
+---
+'@backstage/backend-plugin-api': patch
+---
+
+Added stricter type checks in `isDatabaseConflictError`.
diff --git a/packages/backend-plugin-api/src/services/system/types.ts b/packages/backend-plugin-api/src/services/system/types.ts
index 7e4b78b5a1..c6425cca42 100644
--- a/packages/backend-plugin-api/src/services/system/types.ts
+++ b/packages/backend-plugin-api/src/services/system/types.ts
@@ -136,8 +136,8 @@ export function createServiceRef<
   TService,
   TInstances extends 'singleton' | 'multiton',
 >(
-  options: ServiceRefOptions<TService, any, TInstances>,
-): ServiceRef<TService, any, TInstances> {
+  options: ServiceRefOptions<TService, 'root' | 'plugin', TInstances>,
+): ServiceRef<TService, 'root' | 'plugin', TInstances> {
   const { id, scope = 'plugin', multiton = false, defaultFactory } = options;
   return {
     id,
diff --git a/packages/backend-plugin-api/src/services/utilities/database.ts b/packages/backend-plugin-api/src/services/utilities/database.ts
index f5abcd7fba..6a550c0d78 100644
--- a/packages/backend-plugin-api/src/services/utilities/database.ts
+++ b/packages/backend-plugin-api/src/services/utilities/database.ts
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+import { isError } from '@backstage/errors';
+
 /**
  * Tries to deduce whether a thrown error is a database conflict.
  *
@@ -23,7 +25,7 @@
  *          known database engine
  */
 export function isDatabaseConflictError(e: unknown) {
-  const message = (e as any)?.message;
+  const message = isError(e) ? e.message : undefined;
 
   return (
     typeof message === 'string' &&
diff --git a/packages/backend-plugin-api/src/wiring/types.ts b/packages/backend-plugin-api/src/wiring/types.ts
index 28b70b547f..9397cf597b 100644
--- a/packages/backend-plugin-api/src/wiring/types.ts
+++ b/packages/backend-plugin-api/src/wiring/types.ts
@@ -56,7 +56,11 @@ type DepsToInstances<
     [key in string]: ServiceRef<unknown> | ExtensionPoint<unknown>;
   },
 > = {
-  [key in keyof TDeps]: TDeps[key] extends ServiceRef<unknown, any, 'multiton'>
+  [key in keyof TDeps]: TDeps[key] extends ServiceRef<
+    unknown,
+    'root' | 'plugin',
+    'multiton'
+  >
     ? Array<TDeps[key]['T']>
     : TDeps[key]['T'];
 };