From ac0e281977dcc0abec9ef9f3e162aa4c5cd08f48 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Tue, 10 Oct 2023 13:01:43 +0200
Subject: [PATCH] frontend-app-api: tweak error messaging to include more
 information about where undeclared inputs are from

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 .../wiring/createExtensionInstance.test.ts    | 45 ++++++++++++++++++-
 .../src/wiring/createExtensionInstance.ts     | 15 +++++--
 2 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/packages/frontend-app-api/src/wiring/createExtensionInstance.test.ts b/packages/frontend-app-api/src/wiring/createExtensionInstance.test.ts
index 70f70368d3..6e69e99cb7 100644
--- a/packages/frontend-app-api/src/wiring/createExtensionInstance.test.ts
+++ b/packages/frontend-app-api/src/wiring/createExtensionInstance.test.ts
@@ -289,7 +289,50 @@ describe('createExtensionInstance', () => {
         }),
       }),
     ).toThrow(
-      "Failed to instantiate extension 'core.test', received undeclared input(s) 'undeclared'",
+      "Failed to instantiate extension 'core.test', received undeclared input 'undeclared' from extension 'core.test'",
+    );
+  });
+
+  it('should refuse to create an instance with multiple undeclared inputs', () => {
+    expect(() =>
+      createExtensionInstance({
+        attachments: new Map([
+          [
+            'undeclared1',
+            [
+              createExtensionInstance({
+                attachments: new Map(),
+                config: { output: 'many1' },
+                extension: simpleExtension,
+              }),
+            ],
+          ],
+          [
+            'undeclared2',
+            [
+              createExtensionInstance({
+                attachments: new Map(),
+                config: { output: 'many1' },
+                extension: simpleExtension,
+              }),
+              createExtensionInstance({
+                attachments: new Map(),
+                config: { output: 'many1' },
+                extension: simpleExtension,
+              }),
+            ],
+          ],
+        ]),
+        config: undefined,
+        extension: createExtension({
+          id: 'core.test',
+          attachTo: { id: 'ignored', input: 'ignored' },
+          output: {},
+          factory() {},
+        }),
+      }),
+    ).toThrow(
+      "Failed to instantiate extension 'core.test', received undeclared inputs 'undeclared1' from extension 'core.test' and 'undeclared2' from extensions 'core.test', 'core.test'",
     );
   });
 
diff --git a/packages/frontend-app-api/src/wiring/createExtensionInstance.ts b/packages/frontend-app-api/src/wiring/createExtensionInstance.ts
index ad3b858a60..5a325dc0a0 100644
--- a/packages/frontend-app-api/src/wiring/createExtensionInstance.ts
+++ b/packages/frontend-app-api/src/wiring/createExtensionInstance.ts
@@ -60,12 +60,21 @@ function resolveInputs(
   inputMap: AnyExtensionInputMap,
   attachments: Map<string, ExtensionInstance[]>,
 ) {
-  const undeclaredAttachments = Array.from(attachments.keys()).filter(
-    name => inputMap[name] === undefined,
+  const undeclaredAttachments = Array.from(attachments.entries()).filter(
+    ([inputName]) => inputMap[inputName] === undefined,
   );
   if (undeclaredAttachments.length > 0) {
     throw new Error(
-      `received undeclared input(s) '${undeclaredAttachments.join("', '")}'`,
+      `received undeclared input${
+        undeclaredAttachments.length > 1 ? 's' : ''
+      } ${undeclaredAttachments
+        .map(
+          ([k, exts]) =>
+            `'${k}' from extension${exts.length > 1 ? 's' : ''} '${exts
+              .map(e => e.id)
+              .join("', '")}'`,
+        )
+        .join(' and ')}`,
     );
   }