fix: validation of rest parameters (#7433)

packages/transformers/src/validateArgs/transformProgram.ts

@@ -148,11 +148,12 @@ export default function transformProgram(
 			const methodName = method?.getName();
 			if (!methodName) return;
 
-			const parameters = method
+			const parameters: ParameterInfo[] = method
 				.getParameters()
 				.map((p) => {
 					return {
 						name: p.getName(),
+						isRest: p.isRestParameter(),
 						type: p.getType(),
 						typeName: p.getTypeNode()?.getText(),
 					};
@@ -188,9 +189,13 @@ export default function transformProgram(
 				of withMethodAndClassName
 		) {
 			const paramSpreadWithUnknown = parameters.map((p) =>
-				`${p.name}: unknown`
+				`${p.isRest ? "..." : ""}${p.name}: unknown${
+					p.isRest ? "[]" : ""
+				}`
+			).join(", ");
+			const paramSpread = parameters.map((p) =>
+				`${p.isRest ? "..." : ""}${p.name}`
 			).join(", ");
-			const paramSpread = parameters.map((p) => p.name).join(", ");
 
 			const context: TransformContext = {
 				sourceFile: mfile,
@@ -267,6 +272,7 @@ function getTypeName(t: Type<tsm.Type>): string {
 
 interface ParameterInfo {
 	name: string;
+	isRest?: boolean;
 	type: Type<tsm.Type>;
 	typeName: string | undefined;
 }

packages/transformers/test/fixtures/testSpread.mts

@@ -0,0 +1,58 @@
+/* eslint-disable @typescript-eslint/no-unused-expressions */
+import { validateArgs } from "@zwave-js/transformers";
+import assert from "node:assert";
+
+class Test {
+	@validateArgs()
+	foo(...args: number[]): void {
+		args;
+		return void 0;
+	}
+
+	@validateArgs()
+	bar(arg1: string, ...rest: boolean[]): void {
+		arg1;
+		rest;
+		return void 0;
+	}
+}
+
+const test = new Test();
+// These should not throw
+test.foo();
+test.foo(1);
+test.foo(2, 2);
+
+test.bar("a");
+test.bar("a", true);
+test.bar("a", true, false);
+test.bar("a", true, false, true);
+
+// These should throw
+assert.throws(
+	// @ts-expect-error
+	() => test.foo(true, 1),
+	/args is not assignable to Array<number>/,
+);
+assert.throws(
+	// @ts-expect-error
+	() => test.foo(true, 1),
+	/args\[0\] to be a number, got true/,
+);
+
+assert.throws(
+	// @ts-expect-error
+	() => test.foo(undefined),
+	/args\[0\] to be a number, got undefined/,
+);
+
+assert.throws(
+	// @ts-expect-error
+	() => test.bar("a", 1),
+	/rest is not assignable to Array<boolean>/,
+);
+assert.throws(
+	// @ts-expect-error
+	() => test.bar("a", 1),
+	/rest\[0\] to be a boolean, got 1/,
+);