feat(chat): display token usage and tps in message footers (#1094)

app/src/test/java/com/m57/hermescontrol/ui/chat/TokenEstimatorTest.kt

@@ -0,0 +1,43 @@
+package com.m57.hermescontrol.ui.chat
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class TokenEstimatorTest {
+    @Test
+    fun estimate_emptyOrNull_returnsZero() {
+        assertEquals(0, TokenEstimator.estimate(null))
+        assertEquals(0, TokenEstimator.estimate(""))
+    }
+
+    @Test
+    fun estimate_asciiText_usesByteDiv4() {
+        // "test" is 4 bytes -> (4 + 3) / 4 = 1 token
+        assertEquals(1, TokenEstimator.estimate("test"))
+        // 8 chars -> (8 + 3) / 4 = 2 tokens
+        assertEquals(2, TokenEstimator.estimate("testtest"))
+    }
+
+    @Test
+    fun estimate_cjkText_countsDenseCharacters() {
+        // 3 CJK ideographs -> 3 tokens
+        assertEquals(3, TokenEstimator.estimate("你好世界".substring(0, 3)))
+        // 4 Korean Hangul -> 4 tokens
+        assertEquals(4, TokenEstimator.estimate("안녕하세요".substring(0, 4)))
+    }
+
+    @Test
+    fun formatTokenCount_formatsCompactUnits() {
+        assertEquals("42", TokenEstimator.formatTokenCount(42))
+        assertEquals("999", TokenEstimator.formatTokenCount(999))
+        assertEquals("1,500", TokenEstimator.formatTokenCount(1500))
+        assertEquals("12.5k", TokenEstimator.formatTokenCount(12500))
+        assertEquals("1.2M", TokenEstimator.formatTokenCount(1200000))
+    }
+
+    @Test
+    fun formatTps_roundsProperly() {
+        assertEquals("42", TokenEstimator.formatTps(41.6))
+        assertEquals("50", TokenEstimator.formatTps(50.2))
+    }
+}