Improve handling of non-coercable objects in assertEqual (denoland#1385)

js/testing/util.ts

@@ -13,19 +13,29 @@
  limitations under the License.
  */
 
-// TODO(ry) Use unknown here for parameters types.
-// tslint:disable-next-line:no-any
-export function assertEqual(actual: any, expected: any, msg?: string) {
- if (!msg) {
- msg = `actual: ${actual} expected: ${expected}`;
- }
+export function assertEqual(actual: unknown, expected: unknown, msg?: string) {
  if (!equal(actual, expected)) {
+ let actualString: string;
+ let expectedString: string;
+ try {
+ actualString = String(actual);
+ } catch (e) {
+ actualString = "[Cannot display]";
+ }
+ try {
+ expectedString = String(expected);
+ } catch (e) {
+ expectedString = "[Cannot display]";
+ }
  console.error(
  "assertEqual failed. actual =",
- actual,
+ actualString,
  "expected =",
- expected
+ expectedString
  );
+ if (!msg) {
+ msg = `actual: ${actualString} expected: ${expectedString}`;
+ }
  throw new Error(msg);
  }
 }

js/testing/util_test.ts

@@ -17,7 +17,7 @@ import { test } from "./testing.ts";
 import { assert } from "./util.ts";
 import * as util from "./util.ts";
 
-test(async function util_equal() {
+test(function util_equal() {
  assert(util.equal("world", "world"));
  assert(!util.equal("hello", "world"));
  assert(util.equal(5, 5));
@@ -38,3 +38,35 @@ test(async function util_equal() {
  )
  );
 });
+
+test(function util_assertEqual() {
+ const a = Object.create(null);
+ a.b = "foo";
+ util.assertEqual(a, a);
+});
+
+test(function util_assertEqualActualUncoercable() {
+ let didThrow = false;
+ const a = Object.create(null);
+ try {
+ util.assertEqual(a, "bar");
+ } catch (e) {
+ didThrow = true;
+ console.log(e.message);
+ assert(e.message === "actual: [Cannot display] expected: bar");
+ }
+ assert(didThrow);
+});
+
+test(function util_assertEqualExpectedUncoercable() {
+ let didThrow = false;
+ const a = Object.create(null);
+ try {
+ util.assertEqual("bar", a);
+ } catch (e) {
+ didThrow = true;
+ console.log(e.message);
+ assert(e.message === "actual: bar expected: [Cannot display]");
+ }
+ assert(didThrow);
+});