diff --git a/Validator.test.ts b/Validator.test.ts
index 0098b4f..ed0148c 100644
--- a/Validator.test.ts
+++ b/Validator.test.ts
@@ -52,7 +52,7 @@ Deno.test("validate schema (match)", async () => {
     ],
   ];
   for (const [value, constraints] of values) {
-    assertEquals([], await validate(value, constraints));
+    assertEquals(await validate(value, constraints), [], String(value));
   }
 });
 
@@ -92,6 +92,6 @@ Deno.test("validate schema (no match)", async () => {
     ],
   ];
   for (const [value, constraints] of values) {
-    assertNotEquals([], await validate(value, constraints));
+    assertNotEquals(await validate(value, constraints), [], String(value));
   }
 });
diff --git a/validators/array.test.ts b/validators/array.test.ts
index 3681d0c..e084bc7 100644
--- a/validators/array.test.ts
+++ b/validators/array.test.ts
@@ -13,7 +13,7 @@ Deno.test("isArray (match)", async () => {
     ["foo"],
   ];
   for (const value of values) {
-    assertEquals(await validate(value, isArray()), []);
+    assertEquals(await validate(value, isArray()), [], String(value));
   }
 });
 
@@ -33,6 +33,6 @@ Deno.test("isArray (no match)", async () => {
     Symbol(),
   ];
   for (const value of values) {
-    assertNotEquals(await validate(value, isArray()), []);
+    assertNotEquals(await validate(value, isArray()), [], String(value));
   }
 });
diff --git a/validators/boolean.test.ts b/validators/boolean.test.ts
index 15aaaaa..3b61aab 100644
--- a/validators/boolean.test.ts
+++ b/validators/boolean.test.ts
@@ -13,7 +13,7 @@ Deno.test("isBoolean (match)", async () => {
     false,
   ];
   for (const value of values) {
-    assertEquals(await validate(value, isBoolean()), []);
+    assertEquals(await validate(value, isBoolean()), [], String(value));
   }
 });
 
@@ -31,6 +31,6 @@ Deno.test("isBoolean (no match)", async () => {
     Symbol(),
   ];
   for (const value of values) {
-    assertNotEquals(await validate(value, isBoolean()), []);
+    assertNotEquals(await validate(value, isBoolean()), [], String(value));
   }
 });
diff --git a/validators/empty.test.ts b/validators/empty.test.ts
index 7469bb2..f39f6bf 100644
--- a/validators/empty.test.ts
+++ b/validators/empty.test.ts
@@ -80,7 +80,7 @@ Deno.test("isNotEmpty (match)", async () => {
     Symbol("foo"),
   ];
   for (const value of values) {
-    assertEquals(await validate(value, isNotEmpty()), []);
+    assertEquals(await validate(value, isNotEmpty()), [], String(value));
   }
 });
 
@@ -94,6 +94,6 @@ Deno.test("isNotEmpty (no match)", async () => {
     [],
   ];
   for (const value of values) {
-    assertNotEquals(await validate(value, isNotEmpty()), []);
+    assertNotEquals(await validate(value, isNotEmpty()), [], String(value));
   }
 });
diff --git a/validators/logic.test.ts b/validators/logic.test.ts
index 3849290..6abc7f9 100644
--- a/validators/logic.test.ts
+++ b/validators/logic.test.ts
@@ -11,7 +11,7 @@ Deno.test("or (match)", async () => {
     [1, [isString(), isInteger()]],
   ];
   for (const [value, validators] of values) {
-    assertEquals(await validate(value, or(...validators)), []);
+    assertEquals(await validate(value, or(...validators)), [], String(value));
   }
 });
 
@@ -22,6 +22,10 @@ Deno.test("or (no match)", async () => {
     [1, [isString()]],
   ];
   for (const [value, validators] of values) {
-    assertNotEquals(await validate(value, or(...validators)), []);
+    assertNotEquals(
+      await validate(value, or(...validators)),
+      [],
+      String(value),
+    );
   }
 });
diff --git a/validators/number.test.ts b/validators/number.test.ts
index 3b21fef..862dc9a 100644
--- a/validators/number.test.ts
+++ b/validators/number.test.ts
@@ -49,9 +49,13 @@ Deno.test("isInteger (match)", async () => {
     -1,
   ];
   for (const value of values) {
-    assertEquals(await validate(value, isInteger()), []);
+    assertEquals(await validate(value, isInteger()), [], String(value));
   }
-  assertEquals(await validate(NaN, isInteger({ allowNaN: true })), []);
+  assertEquals(
+    await validate(NaN, isInteger({ allowNaN: true })),
+    [],
+    String(NaN),
+  );
 });
 
 Deno.test("isInteger (no match)", async () => {
@@ -67,7 +71,11 @@ Deno.test("isInteger (no match)", async () => {
     0.1,
   ];
   for (const value of values) {
-    assertNotEquals(await validate(value, isInteger()), []);
+    assertNotEquals(await validate(value, isInteger()), [], String(value));
   }
-  assertNotEquals(await validate(NaN, isInteger({ allowNaN: false })), []);
+  assertNotEquals(
+    await validate(NaN, isInteger({ allowNaN: false })),
+    [],
+    String(NaN),
+  );
 });
diff --git a/validators/string.test.ts b/validators/string.test.ts
index 43ac0ef..308cb22 100644
--- a/validators/string.test.ts
+++ b/validators/string.test.ts
@@ -15,7 +15,7 @@ Deno.test("isString (match)", async () => {
     new String("bar"),
   ];
   for (const value of values) {
-    assertEquals(await validate(value, isString()), []);
+    assertEquals(await validate(value, isString()), [], String(value));
   }
 });
 
@@ -31,7 +31,7 @@ Deno.test("isString (no match)", async () => {
     Symbol(),
   ];
   for (const value of values) {
-    assertNotEquals(await validate(value, isString()), []);
+    assertNotEquals(await validate(value, isString()), [], String(value));
   }
 });
 
@@ -47,7 +47,7 @@ Deno.test("isUrl (match)", async () => {
     assertEquals(
       await validate(value, isUrl({ allowLocal: true, allowDataUrl: true })),
       [],
-      "" + value,
+      String(value),
     );
   }
 });
@@ -66,7 +66,7 @@ Deno.test("isUrl (no match)", async () => {
     assertNotEquals(
       await validate(value, isUrl({ allowLocal: true })),
       [],
-      "" + value,
+      String(value),
     );
   }
 });
@@ -88,11 +88,7 @@ Deno.test("isEmail (match)", async () => {
     "firstname-lastname@example.com",
   ];
   for (const value of values) {
-    assertEquals(
-      await validate(value, isEmail()),
-      [],
-      "" + value,
-    );
+    assertEquals(await validate(value, isEmail()), [], String(value));
   }
 });
 
@@ -117,10 +113,6 @@ Deno.test("isEmail (no match)", async () => {
     "Abc..123@example.com",
   ];
   for (const value of values) {
-    assertNotEquals(
-      await validate(value, isEmail()),
-      [],
-      "" + value,
-    );
+    assertNotEquals(await validate(value, isEmail()), [], String(value));
   }
 });
diff --git a/validators/symbol.test.ts b/validators/symbol.test.ts
index baa2069..af19dd0 100644
--- a/validators/symbol.test.ts
+++ b/validators/symbol.test.ts
@@ -12,7 +12,7 @@ Deno.test("isSymbol (match)", async () => {
     Symbol(),
   ];
   for (const value of values) {
-    assertEquals(await validate(value, isSymbol()), []);
+    assertEquals(await validate(value, isSymbol()), [], String(value));
   }
 });
 
@@ -31,6 +31,6 @@ Deno.test("isSymbol (no match)", async () => {
     new Object(),
   ];
   for (const value of values) {
-    assertNotEquals(await validate(value, isSymbol()), []);
+    assertNotEquals(await validate(value, isSymbol()), [], String(value));
   }
 });