check action objects for implementation use

.changeset/lazy-ads-warn.md

@@ -0,0 +1,7 @@
+---
+'@xstate/vscode-server': patch
+---
+
+Action objects (`{ type: 'action1' }`) are now checked as part of the unused action implementation algorithm.
+
+This resolves an issue where action objects could reference a valid implementation but the extension reported a warning that the implementation was unused.

apps/extension/server/src/__tests__/getUnusedActionImplementations.test.ts

@@ -0,0 +1,64 @@
+import { extractMachinesFromFile } from '@xstate/machine-extractor';
+import { DiagnosticSeverity } from 'vscode-languageserver';
+import { getUnusedActionImplementations } from '../diagnostics/getUnusedActionImplementations';
+
+test('returns a Diagnostic for each unused action in the machine', () => {
+  const result = extractMachinesFromFile(`
+		createMachine(
+			{},
+			{
+				actions: {
+					action1: () => {},
+					action2: () => {},
+				},
+			},
+		);
+	`);
+  const diagnostics = getUnusedActionImplementations(
+    result!.machines[0]!,
+    undefined!,
+    undefined!,
+  );
+
+  expect(diagnostics).toHaveLength(2);
+
+  for (const action of ['action1', 'action2']) {
+    expect(diagnostics).toContainEqual({
+      message: `${action} is never used in the machine definition`,
+      range: {
+        start: {
+          character: expect.any(Number),
+          line: expect.any(Number),
+        },
+        end: {
+          character: expect.any(Number),
+          line: expect.any(Number),
+        },
+      },
+      severity: DiagnosticSeverity.Warning,
+    });
+  }
+});
+
+test('does not return a Diagnostic for actions used in the machine', () => {
+  const result = extractMachinesFromFile(`
+		createMachine(
+			{
+				entry: ['action1', { type: 'action2' }],
+			},
+			{
+				actions: {
+					action1: () => {},
+					action2: () => {},
+				},
+			},
+		);
+	`);
+  const diagnostics = getUnusedActionImplementations(
+    result!.machines[0]!,
+    undefined!,
+    undefined!,
+  );
+
+  expect(diagnostics).toHaveLength(0);
+});

apps/extension/server/src/diagnostics/getUnusedActionImplementations.ts

@@ -9,7 +9,7 @@ export const getUnusedActionImplementations: DiagnosticGetter = (
   machineResult,
 ) => {
   const allActions = getSetOfNames(
-    machineResult.getAllActions(['named']) || [],
+    machineResult.getAllActions(['named', 'object']) || [],
   );
 
   const unusedActions =