2 files changed, 20 insertions, 14 deletions
diff --git a/src/jsMain/kotlin/io/Path.kt b/src/jsMain/kotlin/io/Path.kt
index 20e4a90..241c559 100644
--- a/src/jsMain/kotlin/io/Path.kt
+++ b/src/jsMain/kotlin/io/Path.kt
@@ -60,21 +60,16 @@ sealed class Path {
 		fun relativize(path: Path): Relative = when (path) {
 			is Relative -> path
 			is Absolute -> {
-				var commonPrefix = true
-				val partList = mutableListOf<String>()
-				var returns = 0
-				for ((idx, part) in path.parts.withIndex()) {
-					if (idx < this.parts.size) {
-						if (this.parts[idx] == part && commonPrefix) {
-							continue
-						} else {
-							commonPrefix = false
-							returns++
-						}
-					}
-					partList.add(part)
+				var idx = 0
+				while (idx < path.parts.size && idx < parts.size && path.parts[idx] == parts[idx]) {
+					idx++
 				}
-				Relative(List(returns) { ".." } + partList)
+				val returns = if (idx < parts.size) {
+					parts.size - idx
+				} else {
+					0
+				}
+				Relative(List(returns) { ".." } + path.parts.subList(idx, path.parts.size))
 			}
 		}
 	}
diff --git a/src/jsTest/kotlin/io/PathTest.kt b/src/jsTest/kotlin/io/PathTest.kt
index 174c2b2..9ba8a9e 100644
--- a/src/jsTest/kotlin/io/PathTest.kt
+++ b/src/jsTest/kotlin/io/PathTest.kt
@@ -90,4 +90,15 @@ class PathTest : FunSpec({
 			}
 		}
 	}
+	test("relaitivization works") {
+		forAll(
+			row("/a/b", "/a", ".."),
+			row("/a", "/a/b", "b"),
+			row("/a/b", "/a/c", "../c"),
+		) { a, b, c ->
+			assertSoftly {
+				Path.of(a).shouldBeTypeOf<Path.Absolute>().relativize(Path.of(b)) shouldBe Path.of(c)
+			}
+		}
+	}
 })