diff --git a/src/jvmTest/kotlin/com/sunnychung/application/multiplatform/hellohttp/test/bigtext/BigTextVerifyImpl.kt b/src/jvmTest/kotlin/com/sunnychung/application/multiplatform/hellohttp/test/bigtext/BigTextVerifyImpl.kt
index 19fb6992..c4b32a76 100644
--- a/src/jvmTest/kotlin/com/sunnychung/application/multiplatform/hellohttp/test/bigtext/BigTextVerifyImpl.kt
+++ b/src/jvmTest/kotlin/com/sunnychung/application/multiplatform/hellohttp/test/bigtext/BigTextVerifyImpl.kt
@@ -46,7 +46,7 @@ internal class BigTextVerifyImpl(bigTextImpl: BigTextImpl) : BigText {
     val originalLength: Int
         get() = length - transformOffsetsByPosition.values.sum()
 
-    private data class TransformOp(val originalRange: IntRange, val replaceMapping: BigTextTransformOffsetMapping)
+    private data class TransformOp(val originalRange: IntRange, val offsetMapping: BigTextTransformOffsetMapping)
 
     override fun buildString(): String {
         val r = bigTextImpl.buildString()
@@ -86,6 +86,7 @@ internal class BigTextVerifyImpl(bigTextImpl: BigTextImpl) : BigText {
             println("VerifyImpl pos $pos offset $it")
         }
         stringImpl.insertAt(pos, text)
+//        transformOps += TransformOp(pos until pos + text.length, BigTextTransformOffsetMapping.WholeBlock)
         verify()
         return r
     }
@@ -104,6 +105,7 @@ internal class BigTextVerifyImpl(bigTextImpl: BigTextImpl) : BigText {
             val offset = transformOffsetsByPosition.subMap(0, start).values.sum()
             stringImpl.delete(offset + start, offset + endExclusive)
         }
+        transformOps += TransformOp(start until endExclusive, BigTextTransformOffsetMapping.WholeBlock)
         println("new len = ${bigTextImpl.length}")
         verify()
         return r
@@ -219,10 +221,10 @@ internal class BigTextVerifyImpl(bigTextImpl: BigTextImpl) : BigText {
             val mapped = i + offsetSum
             if (mapped > transformedPosition) {
                 if (result != null) {
-                    return transformOps.firstOrNull { it.replaceMapping == BigTextTransformOffsetMapping.WholeBlock && it.originalRange.first == start }
+                    return transformOps.firstOrNull { it.offsetMapping == BigTextTransformOffsetMapping.WholeBlock && it.originalRange.first == start }
                         ?.originalRange
                         ?.endInclusive
-                        ?.let { it + 1 }
+                        ?.let { maxOf(it + 1, result!!) }
                         ?: result
                 }
                 return i
diff --git a/src/jvmTest/kotlin/com/sunnychung/application/multiplatform/hellohttp/test/bigtext/transform/BigTextTransformPositionCalculatorTest.kt b/src/jvmTest/kotlin/com/sunnychung/application/multiplatform/hellohttp/test/bigtext/transform/BigTextTransformPositionCalculatorTest.kt
index f8a5e51a..cf15e87b 100644
--- a/src/jvmTest/kotlin/com/sunnychung/application/multiplatform/hellohttp/test/bigtext/transform/BigTextTransformPositionCalculatorTest.kt
+++ b/src/jvmTest/kotlin/com/sunnychung/application/multiplatform/hellohttp/test/bigtext/transform/BigTextTransformPositionCalculatorTest.kt
@@ -90,6 +90,22 @@ class BigTextTransformPositionCalculatorTest {
         v.verifyPositionCalculation()
     }
 
+    @ParameterizedTest
+    @ValueSource(ints = [1048576, 64, 16])
+    fun transformDeleteWholeText(chunkSize: Int) {
+        val t = BigTextImpl(chunkSize = chunkSize).apply {
+            append("1234567890<234567890<bcdefghij<BCDEFGHIJ<row break< should h<appen her<e.")
+        }
+        val tt = BigTextTransformerImpl(t).apply {
+            setLayouter(MonospaceTextLayouter(FixedWidthCharMeasurer(16f)))
+            setContentWidth(16f * 10)
+        }
+        val v = BigTextVerifyImpl(tt)
+        val originalLength = v.originalLength
+        v.delete(0 until originalLength)
+        v.verifyPositionCalculation()
+    }
+
     @ParameterizedTest
     @ValueSource(ints = [1048576, 64, 16])
     fun simpleIncrementalTransformReplaces(chunkSize: Int) {
@@ -261,4 +277,110 @@ class BigTextTransformPositionCalculatorTest {
             replaceMapping = BigTextTransformOffsetMapping.WholeBlock
         )
     }
+
+    @ParameterizedTest
+    @ValueSource(ints = [1048576, 64, 16])
+    fun mixedTransformReplaces(chunkSize: Int) {
+        val t = BigTextImpl(chunkSize = chunkSize).apply {
+            append("1234567890<234567890<bcdefghij<BCDEFGHIJ<row break< should h<appen her<e.")
+        }
+        val tt = BigTextTransformerImpl(t).apply {
+            setLayouter(MonospaceTextLayouter(FixedWidthCharMeasurer(16f)))
+            setContentWidth(16f * 10)
+        }
+        val v = BigTextVerifyImpl(tt)
+        val originalLength = v.originalLength
+
+        v.replace(32 .. 36, "long replacement", BigTextTransformOffsetMapping.Incremental)
+        v.verifyPositionCalculation()
+
+        v.replace(15 .. 23, "!?", BigTextTransformOffsetMapping.WholeBlock)
+        v.verifyPositionCalculation()
+
+        v.replace(0 .. 2, "-+-+-", BigTextTransformOffsetMapping.WholeBlock)
+        v.verifyPositionCalculation()
+
+        v.replace(originalLength - 12 until originalLength, "*-*-*", BigTextTransformOffsetMapping.Incremental)
+        v.verifyPositionCalculation()
+
+        v.replace(3 .. 3, "some relatively long string that is longer than a chunk", BigTextTransformOffsetMapping.Incremental)
+        v.verifyPositionCalculation()
+
+        v.replace(4 .. 5, "=", BigTextTransformOffsetMapping.WholeBlock)
+        v.verifyPositionCalculation()
+    }
+
+    @ParameterizedTest
+    @ValueSource(ints = [1048576, 64, 16])
+    fun mixedTransforms(chunkSize: Int) {
+        val t = BigTextImpl(chunkSize = chunkSize).apply {
+            append("1234567890<234567890<bcdefghij<BCDEFGHIJ<row break< should h<appen her<e.")
+        }
+        val tt = BigTextTransformerImpl(t).apply {
+            setLayouter(MonospaceTextLayouter(FixedWidthCharMeasurer(16f)))
+            setContentWidth(16f * 10)
+        }
+        val v = BigTextVerifyImpl(tt)
+        val originalLength = v.originalLength // 73
+
+        v.insertAt(8, "inserted text 8")
+        v.verifyPositionCalculation()
+
+        v.delete(40 .. 52)
+//        isD = true
+        v.verifyPositionCalculation()
+
+        v.replace(32 .. 36, "long replacement", BigTextTransformOffsetMapping.Incremental)
+        v.verifyPositionCalculation()
+
+        v.delete(26 .. 28)
+        v.verifyPositionCalculation()
+
+        v.insertAt(29, "XYZ")
+//        isD = true
+        v.verifyPositionCalculation()
+
+        v.delete(24 .. 24)
+        v.verifyPositionCalculation()
+
+        v.replace(15 .. 23, "!?", BigTextTransformOffsetMapping.WholeBlock)
+        isD = true
+        v.verifyPositionCalculation()
+
+        v.replace(0 .. 2, "-+-+-", BigTextTransformOffsetMapping.WholeBlock)
+        v.verifyPositionCalculation()
+
+        v.insertAt(0, "inserted text at the beginning")
+        v.verifyPositionCalculation()
+
+        v.replace(originalLength - 12 until originalLength - 8, "*-*-*", BigTextTransformOffsetMapping.WholeBlock)
+        v.verifyPositionCalculation()
+
+        v.delete(originalLength - 8 until originalLength)
+        v.verifyPositionCalculation()
+
+        v.replace(3 .. 3, "some relatively long string that is longer than a chunk", BigTextTransformOffsetMapping.Incremental)
+        v.verifyPositionCalculation()
+
+        v.insertAt(3, "inserted text 3")
+        v.verifyPositionCalculation()
+
+        v.replace(4 .. 5, "=", BigTextTransformOffsetMapping.WholeBlock)
+        v.verifyPositionCalculation()
+
+        v.insertAt(53, "^")
+        v.verifyPositionCalculation()
+
+        v.delete(54 .. 54)
+        v.verifyPositionCalculation()
+
+        v.replace(55 .. 55, "_")
+        v.verifyPositionCalculation()
+
+        v.delete(56 .. 59)
+        v.verifyPositionCalculation()
+
+        v.insertAt(56, "qwerty")
+        v.verifyPositionCalculation()
+    }
 }