Convert "lift return / assignment" intentions into a single inspection

Also includes minor test fix, related to KT-14900

idea/testData/inspectionsLocal/liftOut/ifToAssignment/.inspection

@@ -0,0 +1 @@
+org.jetbrains.kotlin.idea.inspections.LiftReturnOrAssignmentInspection

idea/testData/inspectionsLocal/liftOut/ifToAssignment/cascadeIf.kt

@@ -0,0 +1,18 @@
+// WITH_RUNTIME
+fun test(x: Any) {
+    var res: String
+    <caret>if (x is String)
+        when {
+            x.length > 3 -> res = "long string"
+            else -> res = "short string"
+        }
+    else if (x is Int)
+        when {
+            x > 999 || x < -99 -> res = "long int"
+            else -> res = "short int"
+        }
+    else if (x is Long)
+        TODO()
+    else
+        res = "I don't know"
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/cascadeIf.kt.after

@@ -0,0 +1,18 @@
+// WITH_RUNTIME
+fun test(x: Any) {
+    var res: String
+    <caret>res = if (x is String)
+        when {
+            x.length > 3 -> "long string"
+            else -> "short string"
+        }
+    else if (x is Int)
+        when {
+            x > 999 || x < -99 -> "long int"
+            else -> "short int"
+        }
+    else if (x is Long)
+        TODO()
+    else
+        "I don't know"
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/ifElseIf.kt

@@ -0,0 +1,9 @@
+// PROBLEM: none
+
+fun test(n: Int) {
+    var a: String = ""
+    <caret>if (n == 1)
+        a = "one"
+    else if (n == 2)
+        a = "two"
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/ifElseIfElse.kt

@@ -0,0 +1,9 @@
+fun test(n: Int) {
+    val a: String
+    <caret>if (n == 1)
+        a = "one"
+    else if (n == 2)
+        a = "two"
+    else
+        a = "three"
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/ifElseIfElse.kt.after

@@ -0,0 +1,9 @@
+fun test(n: Int) {
+    val a: String
+    <caret>a = if (n == 1)
+        "one"
+    else if (n == 2)
+        "two"
+    else
+        "three"
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/ifElseifElseInconsistent.kt

@@ -0,0 +1,12 @@
+// PROBLEM: none
+
+fun test(n: Int) {
+    val a: String
+    val b: String
+    <caret>if (n == 1)
+        a = "one"
+    else if (n == 2)
+        a = "two"
+    else
+        b = "three"
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/innerIfTransformed.kt

@@ -0,0 +1,23 @@
+fun <T> doSomething(a: T) {}
+
+fun test(n: Int): String {
+    var res: String
+
+    if (n == 1) {
+        <caret>if (3 > 2) {
+            doSomething("***")
+            res = "one"
+        } else {
+            doSomething("***")
+            res = "???"
+        }
+    } else if (n == 2) {
+        doSomething("***")
+        res = "two"
+    } else {
+        doSomething("***")
+        res = "too many"
+    }
+
+    return res
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/innerIfTransformed.kt.after

@@ -0,0 +1,23 @@
+fun <T> doSomething(a: T) {}
+
+fun test(n: Int): String {
+    var res: String
+
+    if (n == 1) {
+        <caret>res = if (3 > 2) {
+            doSomething("***")
+            "one"
+        } else {
+            doSomething("***")
+            "???"
+        }
+    } else if (n == 2) {
+        doSomething("***")
+        res = "two"
+    } else {
+        doSomething("***")
+        res = "too many"
+    }
+
+    return res
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIf.kt

@@ -0,0 +1,7 @@
+fun test(n: Int): String {
+    var res: String
+
+    <caret>if (n == 1) res = "one" else res = "two"
+
+    return res
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIf.kt.after

@@ -0,0 +1,7 @@
+fun test(n: Int): String {
+    var res: String
+
+    <caret>res = if (n == 1) "one" else "two"
+
+    return res
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIfWithAugmentedAssignment.kt

@@ -0,0 +1,7 @@
+fun test(n: Int): String {
+    var res: String = "!"
+
+    <caret>if (n == 1) res += "one" else res += "two"
+
+    return res
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIfWithAugmentedAssignment.kt.after

@@ -0,0 +1,7 @@
+fun test(n: Int): String {
+    var res: String = "!"
+
+    <caret>res += if (n == 1) "one" else "two"
+
+    return res
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIfWithBlocks.kt

@@ -0,0 +1,15 @@
+fun <T> doSomething(a: T) {}
+
+fun test(n: Int): String {
+    var res: String
+
+    <caret>if (n == 1) {
+        doSomething("***")
+        res = "one"
+    } else {
+        doSomething("***")
+        res = "two"
+    }
+
+    return res
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIfWithBlocks.kt.after

@@ -0,0 +1,15 @@
+fun <T> doSomething(a: T) {}
+
+fun test(n: Int): String {
+    var res: String
+
+    <caret>res = if (n == 1) {
+        doSomething("***")
+        "one"
+    } else {
+        doSomething("***")
+        "two"
+    }
+
+    return res
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIfWithShadowedVar.kt

@@ -0,0 +1,18 @@
+// PROBLEM: none
+fun <T> doSomething(a: T) {}
+
+fun test(n: Int): String {
+    var res: String = ""
+
+    <caret>if (n == 1) {
+        doSomething("***")
+        res = "one"
+    } else {
+        var res: String
+
+        doSomething("***")
+        res = "two"
+    }
+
+    return res
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIfWithUnmatchedAssignmentOps.kt

@@ -0,0 +1,12 @@
+// PROBLEM: none
+fun test(s: String): Int {
+    var n: Int = 1;
+
+    <caret>if (s.equals("add")) {
+        n += 1
+    } else {
+        n -= 1
+    }
+
+    return n
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIfWithUnmatchedAssignments.kt

@@ -0,0 +1,13 @@
+// PROBLEM: none
+fun test(n: Int): String {
+    var res: String = ""
+    var res2: String = ""
+
+    <caret>if (n == 1) {
+        res = "one"
+    } else {
+        res2 = "two"
+    }
+
+    return res + res2
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIfWithoutElse.kt

@@ -0,0 +1,13 @@
+// PROBLEM: none
+fun <T> doSomething(a: T) {}
+
+fun test(n: Int): String {
+    var res: String = ""
+
+    <caret>if (n == 1) {
+        doSomething("***")
+        res = "one"
+    }
+
+    return res
+}

idea/testData/inspectionsLocal/liftOut/ifToAssignment/simpleIfWithoutTerminatingAssignment.kt

@@ -0,0 +1,16 @@
+// PROBLEM: none
+fun <T> doSomething(a: T) {}
+
+fun test(n: Int): String {
+    var res: String
+
+    <caret>if (n == 1) {
+        res = "one"
+        doSomething("***")
+    } else {
+        doSomething("***")
+        res = "two"
+    }
+
+    return res
+}