fix: round compact stat badges to nearest instead of truncating

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## 0.8.3 - Unreleased
 
+- Round compact stat badges (issue, PR, star, and release download counts) to the nearest thousand and million instead of truncating, so a count like 19,999 shows as "20K" rather than "19K" and matches GitHub's own compact numbers (thanks @LeoLin990405). (#81)
+
 ## 0.8.2 - 2026-06-12
 
 - Streamline the GitHub API submenu by showing sample age once, while moving shared-budget guidance into a dedicated API settings tab.

Sources/RepoBar/Support/StatValueFormatter.swift

@@ -8,16 +8,21 @@ enum StatValueFormatter {
             return "\(short)K"
         }
         if value < 1_000_000 {
-            return "\(value / 1000)K"
+            let thousands = self.rounded(value, divisor: 1000)
+            return thousands >= 1000 ? "1M" : "\(thousands)K"
         }
         if value < 10_000_000 {
             let short = self.oneDecimal(value, divisor: 1_000_000)
             return "\(short)M"
         }
-        if value >= 1_000_000_000 {
-            return "999M"
-        }
-        return "\(value / 1_000_000)M"
+        let millions = self.rounded(value, divisor: 1_000_000)
+        return millions >= 1000 ? "999M" : "\(millions)M"
+    }
+
+    private static func rounded(_ value: Int, divisor: Int) -> Int {
+        // Round half up without an intermediate `value + divisor/2` that could
+        // overflow near Int.max: compare the remainder against half the divisor.
+        value / divisor + (value % divisor * 2 >= divisor ? 1 : 0)
     }
 
     private static func oneDecimal(_ value: Int, divisor: Double) -> String {
@@ -26,9 +31,6 @@ enum StatValueFormatter {
         if formatted.hasSuffix(".0") {
             return String(formatted.dropLast(2))
         }
-        if formatted.hasPrefix("10") {
-            return "10"
-        }
         return formatted
     }
 }

Tests/RepoBarTests/StatValueFormatterTests.swift

@@ -0,0 +1,55 @@
+@testable import RepoBar
+import Testing
+
+struct StatValueFormatterTests {
+    @Test
+    func `passes through values below one thousand`() {
+        #expect(StatValueFormatter.compact(0) == "0")
+        #expect(StatValueFormatter.compact(42) == "42")
+        #expect(StatValueFormatter.compact(999) == "999")
+    }
+
+    @Test
+    func `keeps one decimal below ten thousand`() {
+        #expect(StatValueFormatter.compact(1000) == "1K")
+        #expect(StatValueFormatter.compact(1500) == "1.5K")
+        #expect(StatValueFormatter.compact(1999) == "2K")
+        #expect(StatValueFormatter.compact(9999) == "10K")
+    }
+
+    @Test
+    func `rounds thousands to nearest instead of truncating`() {
+        #expect(StatValueFormatter.compact(10000) == "10K")
+        #expect(StatValueFormatter.compact(10500) == "11K")
+        #expect(StatValueFormatter.compact(19999) == "20K")
+        #expect(StatValueFormatter.compact(99500) == "100K")
+        #expect(StatValueFormatter.compact(123_456) == "123K")
+    }
+
+    @Test
+    func `rolls rounded thousands up into millions`() {
+        #expect(StatValueFormatter.compact(999_499) == "999K")
+        #expect(StatValueFormatter.compact(999_500) == "1M")
+        #expect(StatValueFormatter.compact(999_999) == "1M")
+    }
+
+    @Test
+    func `keeps one decimal below ten million`() {
+        #expect(StatValueFormatter.compact(1_000_000) == "1M")
+        #expect(StatValueFormatter.compact(1_500_000) == "1.5M")
+        #expect(StatValueFormatter.compact(9_999_999) == "10M")
+    }
+
+    @Test
+    func `rounds millions and caps oversized counts`() {
+        #expect(StatValueFormatter.compact(10_500_000) == "11M")
+        #expect(StatValueFormatter.compact(99_999_999) == "100M")
+        #expect(StatValueFormatter.compact(999_000_000) == "999M")
+        #expect(StatValueFormatter.compact(1_000_000_000) == "999M")
+    }
+
+    @Test
+    func `caps Int.max without integer overflow`() {
+        #expect(StatValueFormatter.compact(Int.max) == "999M")
+    }
+}