diff --git a/iter/iter_test.mbt b/iter/iter_test.mbt
new file mode 100644
index 000000000..ba748db58
--- /dev/null
+++ b/iter/iter_test.mbt
@@ -0,0 +1,144 @@
+// Copyright 2024 International Digital Economy Academy
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+test "empty" {
+  let iter = Iter::empty()
+  let exb = Buffer::make(0)
+  iter.iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect()?
+}
+
+test "singleton" {
+  let iter = Iter::singleton('1')
+  let exb = Buffer::make(0)
+  iter.iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect(~content="1")?
+}
+
+test "repeat" {
+  let iter = Iter::repeat('1')
+  let exb = Buffer::make(0)
+  iter.take(3).iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect(~content="111")?
+}
+
+test "count" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  @assertion.assert_eq(iter.count(), 5)?
+}
+
+test "take" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  let exb = Buffer::make(0)
+  iter.take(3).iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect(~content="123")?
+}
+
+test "take_while" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  let exb = Buffer::make(0)
+  iter.take_while(fn { x => x != '4' }).iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect(~content="123")?
+}
+
+test "drop" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  let exb = Buffer::make(0)
+  iter.drop(3).iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect(~content="45")?
+}
+
+test "drop_while" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  let exb = Buffer::make(0)
+  iter.drop_while(fn { x => x != '4' }).iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect(~content="45")?
+}
+
+test "filter" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  let exb = Buffer::make(0)
+  iter.filter(fn { x => x != '4' }).iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect(~content="1235")?
+}
+
+test "map" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  let exb = Buffer::make(0)
+  iter.map(fn { x => Char::from_int(x.to_int() + 1) }).iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect(~content="23456")?
+}
+
+test "flat_map" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  let exb = Buffer::make(0)
+  iter.flat_map(fn { x => Iter::repeat(x).take(2) }).iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect(~content="1122334455")?
+}
+
+test "fold" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  let result = Char::from_int(iter.fold(fn { acc, x => acc + x.to_int() }, 0) / 5)
+  @assertion.assert_eq(result, '3')?
+}
+
+test "find_first" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  let result = iter.find_first(fn { x => x > '3' })
+  @assertion.assert_eq(result, Some('4'))?
+  let result2 = iter.find_first(fn { x => x > '5' })
+  @assertion.assert_eq(result2, None)?
+}
+
+test "tap" {
+  let iter = from_array(['1', '2', '3', '4', '5'])
+  let exb = Buffer::make(0)
+  iter.tap(fn { x => exb.write_char(x) }).iter(fn {
+    x => exb.write_char(x)
+  })
+  exb.expect(~content="1234512345")?
+}
+
+// For testing purposes
+fn from_array[T](arr: Array[T]) -> Iter[T] {
+  Iter::_unstable_internal_make(fn {
+    yield => {
+      for i = 0; i < arr.length(); i = i + 1 {
+        if yield(arr[i]).not() {
+          break
+        }
+      }
+    }
+  })
+}
diff --git a/iter/moon.pkg.json b/iter/moon.pkg.json
index 144575e9d..67cfc54ae 100644
--- a/iter/moon.pkg.json
+++ b/iter/moon.pkg.json
@@ -3,5 +3,8 @@
         "moonbitlang/core/builtin",
         "moonbitlang/core/assertion",
         "moonbitlang/core/coverage"
+    ],
+    "test_import": [
+        "moonbitlang/core/char"
     ]
 }