if to when intention now detects effectively else branches in subsequent code + performs more accurate comment handling #KT-10750 Fixed

Also #KT-11424 Fixed

idea/testData/intentions/branched/ifWhen/ifToWhen/combinedIf.kt

@@ -0,0 +1,8 @@
+fun bar(arg: Int): String {
+    <caret>if (arg == 1) return "One"
+    else if (arg == 2) return "Two"
+    if (arg == 0) return "Zero"
+    if (arg == -1) return "Minus One"
+    else if (arg == -2) return "Minus Two"
+    return "Something Complex"
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/combinedIf.kt.after

@@ -0,0 +1,10 @@
+fun bar(arg: Int): String {
+    when (arg) {
+        1 -> return "One"
+        2 -> return "Two"
+        0 -> return "Zero"
+        -1 -> return "Minus One"
+        -2 -> return "Minus Two"
+        else -> return "Something Complex"
+    }
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/ifElseSwallowComments.kt

@@ -0,0 +1,6 @@
+fun foo(arg: Int): Int {
+    // 1
+    <caret>if (arg == 0) return 0
+    // 2
+    else return -1
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/ifElseSwallowComments.kt.after

@@ -0,0 +1,8 @@
+fun foo(arg: Int): Int {
+    // 1
+    when (arg) {
+        0 -> return 0
+// 2
+        else -> return -1
+    }
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/ifElseSwallowReturnComment.kt

@@ -0,0 +1,4 @@
+fun foo(arg: Int): Int {
+    <caret>if (arg == 0) return 0 // 1
+    else return -1 // 2
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/ifElseSwallowReturnComment.kt.after

@@ -0,0 +1,6 @@
+fun foo(arg: Int): Int {
+    when (arg) {
+        0 -> return 0 // 1
+        else -> return -1 // 2
+    }
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/multipleIfFake.kt

@@ -0,0 +1,9 @@
+fun bar(arg: Int): Int {
+    <caret>if (arg < 0) {
+        if (arg == -3) return 0
+    }
+    if (arg > 0) {
+        return 1
+    }
+    return -1
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/multipleIfFake.kt.after

@@ -0,0 +1,9 @@
+fun bar(arg: Int): Int {
+    when {
+        arg < 0 -> if (arg == -3) return 0
+    }
+    if (arg > 0) {
+        return 1
+    }
+    return -1
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/multipleIfWithLongBranches.kt

@@ -0,0 +1,15 @@
+fun foo(arg: Int): Int {
+    <caret>if (arg < 0) {
+        var x = arg + 1
+        x++
+        return x
+    }
+    if (arg > 0) {
+        var y = arg - 1
+        y--
+        return y
+    }
+    var z = arg
+    z *= 2
+    return z
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/multipleIfWithLongBranches.kt.after

@@ -0,0 +1,19 @@
+fun foo(arg: Int): Int {
+    when {
+        arg < 0 -> {
+            var x = arg + 1
+            x++
+            return x
+        }
+        arg > 0 -> {
+            var y = arg - 1
+            y--
+            return y
+        }
+        else -> {
+            var z = arg
+            z *= 2
+            return z
+        }
+    }
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/multipleIfWithReturns.kt

@@ -0,0 +1,17 @@
+fun foo(arg: Any?): Int {
+    // 1
+    <caret>if (arg is Int) {
+        return arg // 2
+    }
+    // 3
+    if (arg is String) {
+        return 42 // 4
+    }
+    // 5
+    if (arg == null) {
+        // 6
+        return 0
+    }
+    // 7
+    return -1 // 8
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/multipleIfWithReturns.kt.after

@@ -0,0 +1,14 @@
+fun foo(arg: Any?): Int {
+    // 1
+    when (arg) {
+        is Int -> return arg // 2
+// 3
+        is String -> return 42 // 4
+// 5
+        null -> // 6
+            return 0
+// 7
+// 8
+        else -> return -1
+    }
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/multipleIfWithSingleReturns.kt

@@ -0,0 +1,6 @@
+fun bar(arg: Int): Int {
+    <caret>if (arg == 1) return 2
+    if (arg == 2) return 5
+    if (arg == 3) return 9
+    return 13
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/multipleIfWithSingleReturns.kt.after

@@ -0,0 +1,8 @@
+fun bar(arg: Int): Int {
+    when (arg) {
+        1 -> return 2
+        2 -> return 5
+        3 -> return 9
+        else -> return 13
+    }
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/secondIfNoThen.kt

@@ -0,0 +1,4 @@
+fun foo(arg: Int) {
+    <caret>if (arg == 0) return
+    if (arg == 1) else return
+}

idea/testData/intentions/branched/ifWhen/ifToWhen/secondIfNoThen.kt.after

@@ -0,0 +1,6 @@
+fun foo(arg: Int) {
+    when (arg) {
+        0 -> return
+    }
+    if (arg == 1) else return
+}