Updated on 2026-08-14

core/ui/src/test/java/com/tangem/core/ui/extensions/StringMaskTest.kt

@@ -0,0 +1,91 @@
+package com.tangem.core.ui.extensions
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+
+class StringMaskTest {
+
+    @Test
+    fun GIVEN_empty_string_WHEN_mask_THEN_returns_empty_string() {
+        // GIVEN
+        val input = ""
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("")
+    }
+
+    @Test
+    fun GIVEN_one_char_WHEN_mask_THEN_returns_asterisk() {
+        // GIVEN
+        val input = "a"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("*")
+    }
+
+    @Test
+    fun GIVEN_two_chars_WHEN_mask_THEN_returns_two_asterisks() {
+        // GIVEN
+        val input = "ab"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("**")
+    }
+
+    @Test
+    fun GIVEN_three_chars_WHEN_mask_THEN_masks_middle_only() {
+        // GIVEN
+        val input = "abc"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("a*c")
+    }
+
+    @Test
+    fun GIVEN_four_chars_WHEN_mask_THEN_masks_middle_two() {
+        // GIVEN
+        val input = "abcd"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("a**d")
+    }
+
+    @Test
+    fun GIVEN_five_chars_WHEN_mask_THEN_keeps_edges_and_two_stars_in_middle() {
+        // GIVEN
+        val input = "abcde"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("ab**de")
+    }
+
+    @Test
+    fun GIVEN_seven_chars_WHEN_mask_THEN_keeps_two_on_each_side_and_two_stars() {
+        // GIVEN
+        val input = "abcdefg"
+
+        // WHEN
+        val actual = input.mask()
+
+        // THEN
+        assertThat(actual).isEqualTo("ab**fg")
+    }
+}